JP2009185014A - Fullerene derivative, its solution and membrane thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multiple addition fullerene derivative having a hydrocarbon group having specific aromaticity as an addition substituent and a fullerene derivative membrane using the same which has high solubility in an ester solvent and excels in optical properties. <P>SOLUTION: The fullerene derivative has a partial structure of a fullerene skeleton represented by formula (I) wherein C<SP>1</SP>is bonded to hydrogen or any substituent; C<SP>6</SP>to C<SP>8</SP>are each independently bonded to an organic group having a structure represented by -Ar-(OH)<SB>n</SB>(wherein Ar is a hydrocarbon group having 8-18C aromaticity and n is an integer of 1-3); and all of C<SP>1</SP>to C<SP>10</SP>are carbons constituting the fullerene skeleton. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a novel fullerene derivative, a solution thereof and a membrane thereof. Specifically, the present invention relates to a fullerene derivative having a specific aromatic hydrocarbon group as a partial structure on a fullerene skeleton, a solution containing the fullerene derivative, and a film containing the fullerene derivative.

Since large-scale synthesis method of fullerene C ₆₀ is established in 1990, studies on fullerene has been energetically developed. As a result, many fullerene derivatives have been synthesized and their various functions have been clarified. Along with this, various applications of fullerenes are being developed.

Among the fullerene derivatives, in particular, in the partial structure represented by the following formula (I) of the fullerene skeleton, a partial structure in which a substituent is added to three carbon atoms (for example, C ^{6 to} C ⁸ ) among C ^{6 to} C ¹⁰ (Hereinafter sometimes referred to as “triple-addition partial structure”) and partial structures in which substituents are added to all of C ^{6 to} C ¹⁰ (hereinafter referred to as “5-fold addition partial structure” as appropriate). Various fullerene derivatives having ..) have been synthesized and reported.

（式(Ｉ)中、Ｃ^１〜Ｃ^１０は何れも、フラーレン骨格を構成する炭素原子を表す。）

(In formula (I), C ^{1 to} C ¹⁰ all represent carbon atoms constituting the fullerene skeleton.)

In the following description, the carbon atoms represented by C ^{1 to} C ¹⁰ of the partial structure represented by the above formula (I) may be simply represented by “C ¹ ” to “C ¹⁰ ”.
Furthermore, in the following description, a substituent bonded to C ^{6 to} C ¹⁰ in the above-described triple addition partial structure and / or pentaaddition partial structure may be referred to as an “addition substituent”.

In addition, the fullerene derivative having the above-described triple addition partial structure and / or pentaaddition partial structure may be called according to the total number of additional substituents. According to this name, a fullerene derivative having one triple addition partial structure is a “triple addition fullerene derivative”, and a fullerene derivative having one five addition structure is a “5-addition fullerene derivative”. A fullerene derivative having two structures is a “6-addition fullerene derivative”, and a fullerene derivative having one triple-addition partial structure and one 5-addition partial structure is “8-addition fullerene derivative”. The two fullerene derivatives are “ten-added fullerene derivatives”.
In addition, fullerene derivatives having one or more of the above-described triple addition partial structure and / or five-fold addition partial structure are collectively referred to as “multiple addition fullerene derivative”.

Among the five-added fullerene derivatives, for example, a _C60 skeleton five-added fullerene derivative has a 50-electron π-electron conjugate and is different from unsubstituted C ₆₀ which is a 60-electron π-electron conjugate. It has configuration and electronic properties.

Further, as the triple added fullerene derivative added fewer of 5 polyaddition fullerene derivative from substituent group, it has also been reported synthesized triple additional C ₇₀ derivative is a π-electron conjugated, for example 66 electron system. These triple addition fullerene derivatives have different physical properties not only from unsubstituted C ₆₀ and C ₇₀ but also from the above five addition C ₆₀ derivatives. From this, each fullerene derivative is expected as a new electron conductive material, semiconductor, bioactive substance and the like.

Multiple addition fullerene derivatives such as 5 polyaddition C ₆₀ derivatives or triple additional C ₇₀ derivative is a unique structure that intensive organic group is attached to a particular site fullerenes, because they and have a long π electron conjugated I am interested in its electrochemical properties.

By the way, in order to use a fullerene derivative as a ligand of an electronic material or a metal complex, or to use it as an intermediate of another fullerene derivative, it is preferable that the fullerene derivative exhibits high solubility in an organic solvent. .
Conventionally, some multi-addition fullerene derivatives have been developed that are soluble in aromatic hydrocarbon solvents such as toluene, halogen solvents such as chloroform, aliphatic hydrocarbon solvents such as hexane, and the like.

  Furthermore, from the viewpoints of safety and volatility, propylene glycol-1-monomethyl ether-2-acetate (hereinafter sometimes referred to as “PGMEA” as appropriate) is easy to handle and generally used in industrial applications. A multi-addition fullerene derivative exhibiting high solubility in an ester solvent represented by the above has been developed (see Patent Document 1).

JP 2006-56878 A

  In order to further expand the field of application of fullerene, not only has a high hydroxyl group solubility in PGMEA and a hydroxyl group as a reaction starting point, but also a fullerene derivative having a low absorbance at a wavelength of 193 nm, and a k value at a wavelength of 193 nm A fullerene derivative film having a low (extinction coefficient) has been desired.

  In the conventional technique represented by the above-mentioned Patent Document 1, a multiple having a phenyl group (phenol group) having one or more hydroxyl groups as an additional substituent for the purpose of improving the solubility in various solvents. Addition fullerene derivatives have been synthesized, but when a phenyl group is used as an addition substituent, there is strong absorption at a wavelength of 193 nm, and for applications that require transparency, it may be difficult to apply these fullerene derivatives. there were.

The present invention has been made in view of the above-described problems.
That is, the present invention is a multiple addition fullerene derivative having a hydrocarbon group having a specific aromaticity as an addition substituent, has high solubility in an ester solvent such as PGMEA, and has an absorbance at a wavelength of 193 nm. An object is to provide a low fullerene derivative, a solution containing the fullerene derivative, and a fullerene derivative film having a low k value at a wavelength of 193 nm.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor has a hydrocarbon group having a specific aromaticity in which π conjugation is extended and a group having 1 to 3 hydroxyl groups as an additional substituent. By introducing it, a fullerene derivative having high solubility in an ester solvent such as PGMEA, a high reactive site, and low absorbance at a wavelength of 193 nm was developed and the present invention was completed.

（式(Ｉ)中、Ｃ^１〜Ｃ^１０は何れも、フラーレン骨格を構成する炭素原子を表す。）

（式(II)中、Ａｒは炭素数８〜１８の芳香族性を有する炭化水素基を表し、ｎは１〜３の整数を表す。） That is, the gist of the present invention is that in the partial structure represented by the following formula (I) of the fullerene skeleton, C ¹ is bonded to a hydrogen atom or an arbitrary substituent, and C ^{6 to} C ⁸ are each independently And a fullerene derivative which is bonded to an organic group having a structure represented by the following formula (II) (claim 1).

(In formula (I), C ^{1 to} C ¹⁰ all represent carbon atoms constituting the fullerene skeleton.)

(In the formula (II), Ar represents an aromatic hydrocarbon group having 8 to 18 carbon atoms, and n represents an integer of 1 to 3)

  In the present invention, Ar in the formula (II) is preferably a condensed polycyclic hydrocarbon group having 8 to 18 carbon atoms (claim 2).

The C ^{6 to} C ¹⁰ are preferably each independently bonded to an organic group having a structure represented by the formula (II).

In the fullerene derivative, C ¹ is bonded to a hydrogen atom or an arbitrary substituent, and C ^{6 to} C ⁸ and / or C ^{6 to} C ¹⁰ are each independently represented by the formula (II). It may have a plurality of partial structures represented by the formula (I) bonded to an organic group having a structure as defined above (claim 4).

Further, Ar in the formula (II) is preferably a naphthalene skeleton (Claim 5), and n is preferably 1 (Claim 6). In particular, the formula (II) is represented by the following formula: A structure represented by (III) is preferred (claim 7).

The C ¹ is preferably bonded to an organic group having 1 to 30 carbon atoms (Claim 6).

At this time, the C ¹ is preferably bonded to a methyl group (Claim 9) or an alkenyl group (Claim 10).

Further, the fullerene skeleton is preferably fullerene C ₆₀ or fullerene C ₇₀ (claims 11 and 12).
The fullerene skeleton may contain fullerenes other than fullerenes C ₆₀ and C ₇₀ (claim 13).

  Another gist of the present invention resides in a fullerene derivative solution obtained by dissolving such a fullerene derivative of the present invention in a solvent (claim 14).

  In this case, the solvent is preferably an ester solvent (claim 15).

  Still another subject matter of the present invention resides in a fullerene derivative film comprising the fullerene derivative of the present invention (claim 16).

  According to the present invention, a fullerene derivative having high solubility and a reactive site in an ester solvent such as PGMEA and having a low absorbance at a wavelength of 193 nm, a fullerene derivative solution containing the same, and a k value at a wavelength of 193 nm A fullerene derivative film having a low (extinction coefficient) can be realized.

  Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and can be arbitrarily modified and implemented without departing from the scope of the invention.

[1. Fullerene derivative]
[1-1. Fullerene Derivative Structure]
The fullerene derivative of the present invention is a fullerene derivative having a specific partial structure.
Here, “fullerene” is a carbon cluster having a closed shell structure. The carbon number of fullerene is usually an even number of 60 to 130.

Specific examples of fullerene include C ₆₀ , C ₇₀ , C ₇₆ , C ₇₈ , C ₈₂ , C ₈₄ , C ₉₀ , C ₉₄ , C ₉₆ and higher carbon clusters having more carbon than these. It is done.
Note that in this specification, a fullerene skeleton having i carbon atoms (where i represents an arbitrary natural number) is appropriately represented by a general formula “C _i ”.

  The “fullerene derivative” is a general term for compounds or compositions having a fullerene skeleton. That is, fullerene derivatives include those having a substituent on the fullerene skeleton, those containing a metal or a compound inside the fullerene skeleton, and those having a complex formed with another metal atom or compound.

Fullerene skeleton having the fullerene derivative of the present invention is not limited, inter alia mixtures of _{C 60,} C _{70, C 60} and _{C 70,} or _{C 60} and _{C 70} non-fullerene skeleton are _preferred, C _60, C _{70, C 60} more preferably a mixture of _{C 70} and, particularly preferably _{C 60.} Since C ₆₀ and C ₇₀ are obtained as the main product in the production of fullerenes, the advantage that is easily available. That is, the fullerene derivative of the present invention is preferably a C ₆₀ or C ₇₀ derivative. Among these, the C ₆₀ derivative is particularly advantageous because it is easy to obtain due to its large production volume, and since it can easily form a 5-fold adduct or more multiple adduct when it is used as a derivative and its solubility is improved. It is more preferable that In addition, when a derivative is used, a lot of π-conjugated systems derived from the fullerene skeleton remain, and when this is used for a resist, a C ₇₀ derivative is preferable from the viewpoint of improving etching resistance.
Also, in terms of cost, it is preferably a mixture of C ₆₀ derivatives and C ₇₀ derivatives. In this case, the mixing ratio of the C ₆₀ derivative and C ₇₀ derivatives are any, may be determined from the ranges depending on the application of the derivatives.

Note that the fullerene skeleton of the fullerene derivative of the present invention may contain fullerenes other than fullerenes C ₆₀ and C ₇₀ . In this case, other fullerenes include C ₇₆ , C ₇₈ , C ₈₂ , C ₈₄ , C ₉₀ , C ₉₄ , C _{96 and the} like. The content of other fullerenes is arbitrary, and a preferable range may be set depending on the application.

（式(Ｉ)中、Ｃ^１〜Ｃ^１０は何れも、フラーレン骨格を構成する炭素原子を表す。） In the fullerene derivative of the present invention, in the partial structure represented by the following formula (I) of the fullerene skeleton, C ¹ is bonded to a hydrogen atom or an arbitrary substituent, and at least C ^{6 to} C ⁸ are each independently And is bonded to an organic group having a structure represented by the following formula (II). In the following description, the hydrogen atom and substituent bonded to C ¹ are collectively referred to as “R ¹⁰ ” as appropriate. Further, an organic group having a structure represented by the following formula (II) is appropriately referred to as “R ²⁰ ”.

(In formula (I), C ^{1 to} C ¹⁰ all represent carbon atoms constituting the fullerene skeleton.)

（式(II)中、Ａｒは炭素数８〜１８の芳香族性を有する炭化水素基を表し、ｎは１〜３の整数を表す。）

(In the formula (II), Ar represents an aromatic hydrocarbon group having 8 to 18 carbon atoms, and n represents an integer of 1 to 3)

Hereinafter, the group bonded to C ¹ (namely, R ¹⁰ ) will be described in detail.
In the formula (I), C ¹ is bonded to a hydrogen atom or an optional substituent (that is, R ¹⁰ ). There is no limitation on the type of the substituent, provided that it does not significantly impair the excellent physical properties of the fullerene derivative of the present invention.

When R ¹⁰ is a substituent, examples thereof include a halogen atom, an organic group, and other substituents.

When R ¹⁰ is a halogen atom, specific examples thereof include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these, a chlorine atom and a bromine atom are preferable because of ease of production.

When R ¹⁰ is an organic group, specific examples thereof include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, isopropyl group, sec- Linear or branched chain alkyl group such as butyl group, iso-butyl group, tert-butyl group, tert-amyl group, 2-methylbutyl group, 3-methylbutyl group; cyclopropyl group, cyclobutyl group, cyclopentyl group, Cyclic alkyl groups such as cyclohexyl group; alkenyl groups such as allyl group, crotyl group, cinnamyl group; aralkyl groups such as benzyl group, p-methoxybenzyl group, phenylethyl group; phenyl group, biphenyl group, naphthyl group, anthracenyl group, Aryl groups such as toluyl groups; alkoxy groups such as methoxy groups and ethoxy groups; phenoxy groups Aryloxy groups such as monomethylamino group, dimethylamino group, monodiethylamino group, diethylamino group, and the like; methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, isopropoxycarbonyl group, butoxycarbonyl group, tert-butoxycarbonyl Alkoxycarbonyl groups such as groups; aryloxycarbonyl groups; 5-membered heterocyclic groups such as thienyl groups, thiazolyl groups, isothiazolyl groups, furyl groups, oxazolyl groups, isoxazolyl groups, pyrrolyl groups, imidazolyl groups, pyrazolyl groups; pyridyl groups, pyridazyl groups Groups, pyrimidyl groups, pyrazyl groups, piperidyl groups, piperazyl groups, morpholyl groups and other 6-membered heterocyclic groups; thioformyl groups, thioacetyl groups, thiobenzoyl groups and other thiocarbonyl groups; Substitution of tilsilyl group, monomethylsilyl group, triethylsilyl group, diethylsilyl group, monoethylsilyl group, triisopropylsilyl group, diisopropylsilyl group, monoisopropylsilyl group, triphenylsilyl group, diphenylsilyl group, monophenylsilyl group, etc. A silyl group etc. are mentioned.

When R ¹⁰ is an organic group, the organic group may further have another substituent as long as the excellent physical properties of the fullerene derivative of the present invention are not significantly impaired. Examples of the substituent that the organic group represented by R ¹⁰ may have include an alkyl group, an alkenyl group, an aryl group, an alkoxy group, a hydroxyl group (hydroxy group), an amino group, a carboxyl group, an alkoxycarbonyl group, a halogen atom, and the like. Is mentioned. In addition, these substituents may be further substituted in multiple by one or more substituents.

Furthermore, when R ¹⁰ is an organic group, the carbon number is arbitrary as long as the effects of the present invention are not significantly impaired, but it is usually 1 or more and usually 30 or less. When R ¹⁰ has a substituent, the number of carbons including the substituent preferably satisfies the above specified range.

When R ¹⁰ is another substituent, specific examples thereof include a hydroxyl group (hydroxy group), an amino group, a mercapto group, a carboxyl group, a cyano group, a silyl group, and a nitro group.

Among the above, preferred groups as R ¹⁰ include a hydrogen atom; a halogen atom; an alkyl group such as a methyl group, an ethyl group, and a propyl group; and an alkenyl group such as an allyl group, a crotyl group, and a cinnamyl group.

Among these, as R ¹⁰ , an alkyl group is more preferable from the viewpoint of ease of synthesis and oxidation resistance, and a methyl group is particularly preferable from the viewpoint of thermal stability and cost. In addition to the ease of synthesis, an alkenyl group is preferable from the viewpoint of improving solubility, and an allyl group, crotyl group, and cinnamyl group are particularly preferable from the viewpoint of cost. Furthermore, in order to improve the refractive index (n value) of the fullerene derivative film, an organic group containing a halogen atom other than a fluorine atom, a sulfur atom, or the like is preferable.

Subsequently, the organic group having a structure represented by the formula (II) (that is, R ²⁰ ) will be described in detail.
R ²⁰ is an organic group in which 1 to 3 hydroxyl groups (OH groups) are bonded to an aromatic hydrocarbon group having 8 to 18 carbon atoms. Any other substituents may be introduced as long as the excellent physical properties of the fullerene derivative of the present invention are not significantly impaired.

Specific examples of the aromatic hydrocarbon group having 8 to 18 carbon atoms to which a hydroxyl group is bonded include vinylphenyl groups such as a vinylphenyl group, a divinylphenyl group, and a trivinylphenyl group; a pentarenyl group. , Indenyl group, naphthyl group, azulenyl group, heptaenyl group, biphenylenyl group, as-indacenyl group, s-indacenyl group, acenaphthylenyl group, fluorenyl group, phenalenyl group, phenanthrenyl group, anthracenyl group, fluoracenyl group, acephenanthrylenyl group , Condensed polycyclic hydrocarbon groups such as an acetylenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, and a tetracenyl group.
Among these, a naphthyl group, anthracenyl group, phenalenyl group, and pyrenyl group are preferable from the viewpoint of raw material procurement, and a naphthyl group is particularly preferable from the viewpoint of ease of synthesis.

  The position where the monovalent hydrocarbon group having 8 to 18 carbon atoms and aromaticity is bonded to the fullerene is not limited, and is arbitrary. For example, in the case of a naphthalene skeleton, from the viewpoint of raw material procurement and ease of synthesis. Bonding at the β-position is preferred. With respect to other skeletons, preferred bonding positions can be determined from the above viewpoint.

  In the formula (II), the number of hydroxyl groups (OH groups) bonded to an aromatic hydrocarbon group having 8 to 18 carbon atoms is 1 to 3. Among these, the number of hydroxyl groups is preferably 1 from the viewpoint of easy reaction control when performing further reactions.

  In addition, the position where the hydroxyl group is bonded to the aromatic hydrocarbon group is not limited and is arbitrary, and when there are a plurality of hydroxyl groups, the relative positional relationship is also not limited and is arbitrary. For example, a naphthol group In this case, from the viewpoint of raw material procurement, it is preferable that it binds to fullerene at the position of amphi (Amphi), that is, β-position (2-position), and a hydroxyl group binds to the position of 6-position.

In the present invention, the organic group having a structure represented by the above formula (II) (that is, R ²⁰ ) is preferably a structure represented by the following formula (III).
In the following, the naphthol group represented by the above formula (III) is represented as “β- (6-OH—C ₁₀ H ₆ )”.

  With respect to other skeletons, preferred bonding positions can be determined from the above viewpoint.

In the fullerene derivative of the present invention, C ^{6 to} C ⁸ in the formula (I) are each independently bonded to an organic group having a structure represented by the formula (II) (that is, R ²⁰ ). From the viewpoint of increasing the solubility in an ester solvent, it is desirable that not only C ^{6 to} C ⁸ but also all of C ^{6 to} C ¹⁰ are each independently bonded to R ²⁰ . R ²⁰ may be groups having the same structure or different structures, but R ²⁰ is preferably all groups having the same structure from the viewpoint of easy synthesis.

In the present specification, an organic compound having a structure in which C ^{1 of} formula (I) is bonded to a hydrogen atom or an arbitrary substituent (ie, R ¹⁰ ), and C ^{6 to} C ⁸ are each independently represented by formula (II). The partial structure bonded to the group (that is, R ²⁰ ) may be referred to as “the triple addition partial structure of the present invention”. In addition, C ¹ in formula (I) is bonded to a hydrogen atom or an arbitrary substituent (that is, R ¹⁰ ), and C ^{6 to} C ¹⁰ are each independently an organic group having a structure represented by formula (II) (that is, , R ²⁰ ) may be referred to as “the 5-addition partial structure of the present invention”.

Examples of the fullerene derivative of the present invention are listed below. However, the fullerene derivative of the present invention is not limited to the examples given below, and may have a plurality of triple addition partial structures and / or multiple double addition partial structures.
- triple added fullerene derivatives represented by having one triple additional partial structure of the general formula _{^{C i (R 20) 3 (}} R 10) of the present invention on the fullerene skeleton.
· 5 polyaddition fullerene derivatives represented by having one quintuple additional partial structure of the general formula _{^{C i (R 20) 5 (}} R 10) of the present invention on the fullerene skeleton.
A hexaaddition fullerene derivative represented by the general formula C _i (R ²⁰ ) ₆ (R ¹⁰ ) ₂ having two triple addition partial structures of the present invention on the fullerene skeleton.
-8 folds represented by the general formula C _i (R ²⁰ ) ₈ (R ¹⁰ ) ₂ having one triple addition partial structure of the present invention and one pentaaddition partial structure of the present invention on the fullerene skeleton Addition fullerene derivative.
A 10-fold addition fullerene derivative represented by the general formula C _i (R ²⁰ ) ₁₀ (R ¹⁰ ) ₂ having two of the 5-fold addition partial structure of the present invention on the fullerene skeleton.

Among these, as the fullerene derivative of the present invention, a pentaaddition fullerene derivative represented by the general formula Ci (R ²⁰ ) ₅ (R ¹⁰ ) having one pentaaddition partial structure of the present invention on the fullerene skeleton. However, it is preferable from the viewpoint of obtaining a single component and facilitating production.

Further, from the viewpoint of improving the solubility and increasing the hydroxyl group which is a reaction active point, the compound represented by the general formula C _i (R ²⁰ ) ₆ (R ¹⁰ ) ₂ having two triple addition partial structures of the present invention on the fullerene skeleton. The hexafold represented by the general formula C _i (R ²⁰ ) ₈ (R ¹⁰ ) ₂ having one triple addition partial structure and one pentaaddition partial structure of the present invention. The 10-addition fullerene derivative represented by the general formula C _i (R ²⁰ ) ₁₀ (R ¹⁰ ) ₂ having two addition-fullerene derivatives and two 5-addition partial structures is preferable.

  In the fullerene derivative of the present invention, the partial structure of the above formula (I) may be a structure observed from the inside of the closed shell structure of the fullerene skeleton or a structure observed from the outside. In other words, when a fullerene derivative is observed from the inside or outside of the closed shell structure of the fullerene skeleton, if at least one of the triple addition partial structure and / or the pentaaddition partial structure of the present invention is present, the present invention It corresponds to the fullerene derivative.

[1-2. Properties of fullerene derivatives]
The fullerene derivative of the present invention is soluble in an ester solvent, that is, has high solubility in an ester solvent.
In this specification, a fullerene derivative is “soluble in an ester solvent” means that a fullerene derivative is mixed with an ester solvent, subjected to ultrasonic irradiation for 10 minutes, and then a precipitate or an insoluble matter is detected visually. Means not. Specifically, per unit volume (1 mL) of the ester solvent with respect to an ester solvent of either propylene glycol-1-monomethyl ether-2-acetate (that is, PGMEA) or ethyl lactate at 25 ° C. and normal pressure. When 10 mg or more of the fullerene derivative is dissolved, it is determined that the fullerene derivative is soluble in the ester solvent, that is, has high solubility in the ester solvent.

  When the fullerene derivative of the present invention is used after being dissolved in an ester solvent, the type of the ester solvent is not limited as long as the fullerene derivative of the present invention is dissolved. Examples of ester solvents include methyl acetate, ethyl acetate, propyl acetate, phenyl acetate, methyl propionate, ethyl propionate, propyl propionate, phenyl propionate, methyl 3-methoxypropionate, methyl 3-ethoxypropionate, lactic acid Linear esters such as methyl and ethyl lactate; cyclic esters such as γ-butyrolactone and caprolactone; ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol-1-monomethyl ether Examples thereof include ether esters such as acetate and propylene glycol-1-monoethyl ether acetate.

Among these, linear esters and ether esters are preferable, and specifically, propylene glycol-1-monomethyl ether-2-acetate (that is, PGMEA) and ethyl lactate are preferable.
In addition, any 1 type may be used for an ester solvent, and 2 or more types may be used together by arbitrary combinations and a ratio.

  These ester solvents are generally used as solvents for manufacturing optical disk materials such as DVD and CD, manufacturing semiconductor integrated circuits, manufacturing masks for manufacturing semiconductor integrated circuits, manufacturing integrated circuits for liquid crystals, and resist materials for manufacturing liquid crystal screens. It is an ester solvent that is commonly used. In addition to the KrF excimer laser and ArF excimer laser that have been developed in the past, the ester solvent is a photoresist that is suitable for shortening the wavelength of light sources such as EUV (extreme ultraviolet light) and EB (electron beam), It is a solvent suitably used for a photoresist, nanoimprint, and interlayer insulating film as a lower layer film material having a function of an antireflection film.

  Therefore, being soluble in the ester solvent, that is, having high solubility in the ester solvent means that the fullerene derivative of the present invention is dissolved in a solvent widely used in the industry as described above. Indicates that it is possible. When the fullerene derivative is dissolved in the ester solvent, the fullerene derivative is often soluble in other organic solvents as well.

  Therefore, the solubility of the fullerene derivative of the present invention in an ester solvent is high. For example, the fullerene derivative of the present invention can be used in organic solar cells such as dye-sensitized solar cells and organic thin film solar cells, organic transistors and diodes, and organic electric fields. General organic devices such as light-emitting elements (organic EL elements) and nonlinear optical materials; resin additives; lubricants; battery substrates for batteries such as insulating films, lithium secondary batteries, fuel cells, capacitors, and additives / surface modifications thereof Coating materials such as separators and other materials and additives that constitute members such as separators; metal and ceramics additives; additives for sliding applications such as solid lubricants and lubricant additives, catalysts, and paints, inks, etc. It shows that it can be applied to various industrial fields such as pharmaceuticals, cosmetics and diagnostics.

  Moreover, the preferable solubility value of the fullerene derivative with respect to the ester solvent described above varies depending on the use of the fullerene derivative. For example, in order to form a coating film for use as a resist material for semiconductor integrated circuit fabrication, semiconductor integrated circuit fabrication mask fabrication, liquid crystal integrated circuit fabrication, and liquid crystal screen fabrication using the fullerene derivative of the present invention, It is desirable that the fullerene derivative has a solubility of usually 10 mg / mL or more, preferably 50 mg / mL or more, more preferably 100 mg / mL or more with respect to the above ester solvent.

The reason why the fullerene derivative of the present invention has high solubility in an ester solvent is not clear, but according to the inventor's inference, in addition to the acidity of the hydroxyl group of R ²⁰ , non-crystal due to a decrease in molecular symmetry It is assumed that there is a synergistic effect with the crystallization effect. Therefore, it is considered that due to these factors, the fullerene derivative of the present invention expresses higher solubility in the ester solvent than expected.

  In addition to the high solubility, the fullerene derivative of the present invention has a specific absorption spectrum in a film state, so that it can be efficiently manufactured as a whole for the light source wavelength and apparatus used in the manufacturing apparatus. It becomes possible to design to realize Furthermore, in the liquid immersion apparatus and the cleaning apparatus, the fullerene derivative of the present invention has a specific contact angle, thereby enabling a design that prevents treatment effects and liquid mixing / diffusion. The fact that the fullerene derivative of the present invention has a specific absorption spectrum enables application to optical parts such as an optical filter, and also has a specific contact angle, thereby forming a protective film by coating. It can also be applied to the above.

In addition, the fullerene derivative of the present invention is usually soluble in an alkaline solvent, that is, has high solubility in an alkaline solvent.
In this specification, a fullerene derivative is “soluble in an alkaline solvent” means that a fullerene derivative is mixed with an alkaline solvent and subjected to ultrasonic irradiation for 10 minutes, and then a precipitate or an insoluble matter is detected visually. Means not. Specifically, when 50 mg or more of the fullerene derivative is dissolved per unit volume (1 mL) of the aqueous sodium hydroxide solution with respect to the aqueous sodium hydroxide solution at 25 ° C. and normal pressure, the fullerene derivative is dissolved in the alkaline solvent. On the other hand, it is judged to be soluble, ie, highly soluble in an alkaline solvent.

  When the fullerene derivative of the present invention is dissolved in an alkali solvent and used, the type of the alkali solvent is not limited as long as the fullerene derivative of the present invention is dissolved. Examples of the alkaline solvent include alkaline organic solvents such as pyridine, piperidine, triethylamine, tri-n-propylamine, methyldiethylamine, 1,8-diazabicyclo- (5,4,0) -7-undecene, dimethylethanolamine, and the like. Sodium hydroxide aqueous solution, lithium hydroxide aqueous solution, calcium hydroxide aqueous solution, sodium carbonate aqueous solution, lithium carbonate aqueous solution, calcium carbonate aqueous solution, ammonia aqueous solution, tetramethylammonium hydroxide aqueous solution and the like. In the case of an alkaline aqueous solution, the concentration of the solute is arbitrary.

Among them, an alkaline aqueous solution is preferable as the alkaline solvent, and an aqueous solution such as an aqueous ammonia solution or an aqueous tetramethylammonium hydroxide solution, which is a nonmetallic alkaline aqueous solution, is preferable for applications where it is desirable to avoid metal contamination in the product.
In addition, any 1 type may be used for these alkaline solvents, and 2 or more types may be used together by arbitrary combinations and a ratio.

  Moreover, although the preferable solubility value of the fullerene derivative with respect to the above-mentioned alkali solvent varies depending on the use of the fullerene derivative, it is desirable that the solubility in the alkali solvent is usually 50 mg / mL or more, preferably 100 mg / mL or more.

The reason why the fullerene derivative of the present invention has high solubility in an alkaline solvent is not clear, but according to the inventor's guess, there are 3 or more R ^20, which is a group containing a phenolic hydroxyl group, locally and This is considered to be due to the fact that the affinity for the alkaline solvent is increased while having the hydrophobic fullerene skeleton due to regioselective binding to the fullerene skeleton.

Moreover, the fullerene derivative of the present invention has very high thermal stability. This is because the fullerene derivative of the present invention retains a large amount of π-electron conjugation of the fullerene skeleton and is bonded with a substituent by a carbon-carbon bond. Can exist stably without decomposition. Therefore, the fullerene derivative of the present invention can also be suitably used for applications requiring heat resistance that cannot be decomposed and used with ordinary organic substances.
The thermal stability of the fullerene derivative of the present invention may be evaluated by a heat resistance test at a high temperature or by using TG-DTA (simultaneous differential thermothermal gravimetric measurement) that can be measured quickly. Absent. In addition, when evaluating by TG-DTA, the kind and quantity of gas to circulate, the kind of bread, the heating rate, the upper limit temperature for measurement, the amount of sample, etc. can be arbitrarily selected according to the physical properties to be measured.

[2. Method for producing fullerene derivative]
There is no restriction | limiting in the method to manufacture the fullerene derivative of this invention, It can manufacture by arbitrary methods.

Conventionally, a general method for producing a fullerene derivative having a triple addition partial structure and / or a pentaaddition partial structure in which a hydrogen atom or a substituent is bonded to C ¹ has already been established. Specifically, when C ¹ is bonded to an organic group, Japanese Patent Application Laid-Open No. 2005-15470 and Chemistry Letters, 2004, p. Reference may be made to the method described in H.328. In the case where C ¹ is bonded to a hydrogen atom, Nature, 419, 2002, p. Reference may be made to the method described in 702-705. Furthermore, if the halogen atom is bonded to ^{C 1,} reference may be made to the method described in JP-A-2002-241389. Regarding the production of 10-, 8- and 6-adducts, the methods described in Angew. Chem. Int. Ed. 2007, 46, P2844-2847 can be referred to.
The fullerene derivative of the present invention can also be produced by the method described in the above document. In this case, the conditions described in the above document can be used as various conditions such as the reaction temperature, the type of solvent, the mixing order of the reagents, and the reaction time. It is possible to adopt.

  Especially, it is preferable to manufacture the fullerene derivative of this invention with the manufacturing method illustrated below. However, the manufacturing method illustrated below is an example of the manufacturing method of the fullerene derivative of this invention, and the manufacturing method of the fullerene derivative of this invention is not limited to the following examples.

In the method for producing a fullerene derivative of the present invention, a fullerene, a transition metal, a Grignard reagent (Grignrad reagent), and a raw material into which R ¹⁰ can be introduced (hereinafter referred to as “R ¹⁰ introduction agent” as appropriate) are prepared. Reaction is performed to obtain the fullerene derivative of the present invention. At this time, a reaction solvent is usually used, and the reaction is allowed to proceed in the reaction solvent.

[2-1. Fullerene]
As the fullerene, [1. Various fullerenes listed as specific examples of fullerenes in the “fullerene derivative” column can be used. In addition, any 1 type may be used for fullerene, and 2 or more types may be used together by arbitrary combinations and a ratio.

[2-2. Transition metal]
In the production method of the present invention, at least one transition metal is present in the reaction system. The type of transition metal is not limited, but is preferably a transition metal selected from metals belonging to Group 10 and Group 11 of the long-period periodic table, and among these, from the viewpoint of reactivity, it is Group 11 metal. Copper metal is particularly preferred.
In addition, as a transition metal made to exist in a reaction system, only 1 type may be used individually and 2 or more types may be used together by arbitrary combinations and a ratio.

In addition, as the transition metal, as long as the reaction proceeds, a single transition metal or a transition metal complex may be used, and a metal compound containing the transition metal (transition metal compound) May be used.
Examples of the transition metal, transition metal complex and metal compound include copper bromide dimethyl sulfide complex, copper bromide dibutyl sulfide complex, copper iodide dimethyl sulfide complex, copper iodide dibutyl sulfide complex, copper chloride dimethyl sulfide complex, Copper chloride dibutyl sulfide complex, copper cyanide, copper fluoride, copper chloride, copper bromide, copper iodide, organic copper-phosphine complex, silver fluoride, silver chloride, silver bromide, silver iodide, gold fluoride, Gold chloride, gold iodide, palladium chloride, palladium bromide, palladium iodide, nickel chloride, nickel bromide, nickel iodide, platinum chloride, platinum bromide, platinum iodide, nickel cyclooctadiene complex, palladium cyclooctadiene Complex, platinum cyclooctadiene complex, nickel-phosphine complex, palladium-phosphine complex, platinum-phosphine Body, and the like. Of these, copper bromide and copper bromide dimethyl sulfide complexes, which are Group 11 metals and monovalent metal compounds and metal complexes, are preferred from the viewpoint of reactivity.
In addition, the transition metal simple substance, complex, and metal compound may be used alone, or two or more kinds may be used in any combination and ratio.

  The content of the transition metal in the reaction system is arbitrary as long as the above reaction proceeds, but the ratio to the fullerene is usually 4 times mol or more, preferably 6 times mol or more, and usually 32 times mol or less, preferably Is preferably 16 times mole or less. If the transition metal content is too high, the production cost increases, and separation from the fullerene derivative may be difficult. If the transition metal content is too low, the reaction may not be completed. In addition, when using together 2 or more types of transition metals, it is desirable for those total amount to satisfy | fill the said range.

[2-3. Grignard reagent]
In the production method of the present invention, at least one Grignard reagent is present in the reaction system. R ²⁰ can be added to the fullerene skeleton by allowing a Grignard reagent to coexist in the reaction system according to the methods described in the above-mentioned patent documents and non-patent documents.

There is no restriction on the blending time of these Grignard reagents as long as the desired fullerene derivative is obtained. However, in the production method of the present invention, before introducing R ¹⁰ , an organic group having a structure represented by formula (II) in C ^{6 to} C ⁸ or C ^{6 to} C ¹⁰ of the partial structure of formula (I) ( It is desirable to carry out the reaction to add R ²⁰ ). For this reason, the Grignard reagent is usually introduced into the reaction system before the reaction in which the R ¹⁰ introduction agent is allowed to act.

As the Grignard reagent, for example, a compound represented by R ²⁰ -MX ′ can be used.
Here, R ²⁰ is as described above, and may be selected according to the structure of the target fullerene derivative of the present invention.
M represents a metal element. Examples of M include Mg, Zn, Hg, Li and the like, but Mg (magnesium atom) is preferable.
X ′ represents a halogen atom. Examples of X ′ include a chlorine atom, a bromine atom, and an iodine atom, with a bromine atom and an iodine atom being preferred, and a bromine atom being particularly preferred.

In R ²⁰ -MX ′ described above, it is usually desirable to introduce a protecting group into the hydroxyl group of R ^{20 and} use the compound into which the protecting group has been introduced as the Grignard reagent. Examples of the protecting group introduced into the hydroxyl group of R ²⁰ include a methyl group, a tetrahydropyranyl group, and a silyl group. In addition, a protecting group may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
In addition, the method for introducing a protecting group varies depending on the protecting group. For example, when the protecting group is a tetrahydropyranyl group, a technique such as allowing dihydropyran to act in the presence of a weak acid can be used.

  In addition, only 1 type may be used for a Grignard reagent, and 2 or more types may be used together by arbitrary combinations and a ratio.

When the above-mentioned Grignard reagent is used, the amount used is usually 4 times mol or more, preferably 6 times mol or more, and usually 48 times mol or less, preferably 32 times mol or less, more preferably in terms of the ratio to the raw material fullerene. Is preferably 16 times mole or less. If the amount of Grignard reagent used is too large, the production cost increases, and a large amount of R ¹⁰ introduction agent used for stopping the reaction may be required. If the amount is too small, the reaction may not be completed.
In addition, when using 2 or more types of Grignard reagents together, it is desirable to make the total amount satisfy the above range.

[2-4. R ¹⁰ introduction agent]
As the R ¹⁰ introduction agent, an appropriate agent may be used depending on the group to be introduced (that is, R ¹⁰ ).
For example, when producing a fullerene derivative in which R ¹⁰ is a hydrogen atom, the R ¹⁰ introduction agent is not particularly limited as long as a hydrogen atom can be introduced into the fullerene skeleton. Examples of the R ¹⁰ introduction agent include acidic aqueous solutions such as an aqueous ammonium chloride solution and an aqueous hydrogen chloride solution. In order to suppress the oxidation reaction, it is preferable to perform an oxidation reaction suppression operation such as degassing so that oxygen is not mixed into the acidic aqueous solution.

For example, when producing a fullerene derivative in which R ¹⁰ is an organic group, the R ¹⁰ introduction agent is not particularly limited as long as the organic group can be introduced into the fullerene skeleton. As an example of the R ¹⁰ introduction agent, the compound R ¹⁰ -X having a structure in which the organic group R ¹⁰ and the leaving group X are bonded to each other can be used. In this case, the leaving group X is not particularly limited as long as it can be a leaving group in a nucleophilic substitution reaction. For example, a halogen atom such as a chlorine atom, a bromine atom or an iodine atom; an acetoxy group, And acyloxy groups such as trifluoroacetoxy group; sulfonyloxy groups such as methanesulfonyloxy group and benzenesulfonyloxy group; and the like. Among these, from the viewpoint of reactivity and raw material procurement, the leaving group X is preferably a halogen atom, and particularly preferably a bromine atom or an iodine atom.

Furthermore, for example, when producing a fullerene derivative in which R ¹⁰ is a halogen atom, there is no other limitation on the R ¹⁰ introduction agent as long as the halogen atom can be introduced into the fullerene skeleton. Examples of the R ¹⁰ introducing agent include halogenating agents such as chlorine, bromine, iodine, N-bromosuccinimide, N-chlorosuccinimide, N-iodosuccinimide and the like. Among these, N-bromosuccinimide is preferable from the viewpoint of reactivity.

In the case of producing a fullerene derivative in which R ¹⁰ is an organic group, and in the case of producing a fullerene derivative in which R ¹⁰ is a halogen atom, for example, an R ¹⁰ introduction agent in a system in which a transition metal is present. May be used, and a method of producing in situ may be used. First, a hydrogen atom is introduced into C ¹ of the fullerene skeleton, followed by treatment with an appropriate base, and then the desired R ¹⁰ is introduced with the R ¹⁰ introducing agent. A method may be used. At this time, an appropriate method may be selected depending on R ^{10 to} be introduced. When using a base, the kind described in JP-A-2005-15470 can be referred to.

Any one of R ¹⁰ introduction agents may be used, or two or more thereof may be used in any combination and ratio. However, in order to obtain a single compound, it is preferable to use only one of them alone.

Among them, with respect to the R ¹⁰ introduction agent, methyl iodide is used from the viewpoint of easy reaction, product stability and cost reduction, and allyl bromide, allyl iodide, crotyl bromide, cinna from the viewpoint of improving solubility. It is preferable to use milbromide alone.

The amount of the R ¹⁰ introduction agent used is usually 1 times mol or more, preferably 5 times mol or more, and usually 100 times mol or less, preferably 50 times mol or less with respect to fullerene. If the amount of the R ¹⁰ introduction agent is too large, it may be disadvantageous in terms of production cost. If the amount of the R ¹⁰ introduction agent is too small, it reacts with the Grignard reagent remaining in the reaction system, and the reaction is halfway. The target compound (fullerene derivative of the present invention) may not be obtained. Note that when used in combination R ¹⁰ introducing agent of two or more, it is desirable that the total amount of them to satisfy the above range.

[2-5. Reaction solvent]
In the method for producing a fullerene derivative of the present invention, at least the above-mentioned fullerene, transition metal, Grignard reagent and R ¹⁰ introduction agent may be used, but a reaction solvent may be further used.
When a reaction solvent is used, the type thereof is arbitrary as long as it is a solvent capable of suitably dissolving and / or dispersing the above-mentioned fullerene, transition metal, Grignard reagent and R ¹⁰ introduction agent.

Examples of reaction solvents include halogen-substituted aromatic solvents such as orthodichlorobenzene (ODCB), chlorobenzene and trichlorobenzene; aromatic solvents such as benzene, toluene, xylene and trimethylbenzene; halogen hydrocarbon solvents such as chloroform and dichloromethane Ether solvents such as diethyl ether, dibutyl ether, tetrahydrofuran (THF), 1,4-dioxane and methylcyclopentyl ether; pyridine solvents such as pyridine, methylpyridine and dimethylpyridine. Among these, a combination of a halogen-substituted aromatic solvent capable of suitably dissolving fullerene and an ether solvent capable of stably dissolving the Grignard reagent is preferable. Specifically, ODCB and THF are used in combination. preferable. In particular, in the production of 10-, 8-, and 6-adducts, it is preferable to use a pyridine solvent in addition to these ether solvents.
In addition, any 1 type may be used for the reaction solvent, and 2 or more types may be used together by arbitrary combinations and a ratio.

When a reaction solvent is used, the amount used is usually 1 mg / mL or more, preferably 5 mg / mL or more, and usually 40 mg / mL or less, preferably 20 mg / mL or less, as a ratio to fullerene. If the amount of the reaction solvent used is too large, the concentration of the raw material becomes thin and the reaction rate may be slow. If the amount is too small, the raw material and the product cannot be dissolved, and the reaction may not proceed completely.
In addition, when using together 2 or more types of reaction solvent, it is desirable to make those total amount satisfy | fill the said range.
Particularly in the production of 10-, 8-, and 6-adducts, when a pyridine solvent is used in the reaction solvent, the ratio of the pyridine solvent to the total amount of the reaction solvent is 5 to 90% by volume, particularly 10 to 80% by volume. %, Most preferably 15 to 70% by volume. In other words, the pyridine solvent is effective in the production of the 10-, 8-, and 6-adducts because the multiple addition reaction proceeds more than the 5-adduct without leaving the 5-adduct. However, if the amount used is too small, this effect by adding the pyridine solvent cannot be sufficiently obtained, and if it is too large, the production cost may increase.

[2-6. Operation and reaction conditions]
The order and reaction conditions for mixing the above-mentioned fullerene, transition metal, Grignard reagent and R ¹⁰ introduction agent, and a reaction solvent used as necessary are arbitrary as long as the fullerene derivative of the present invention can be produced. Further, the reaction system may contain components other than those described above as long as the progress of the reaction is not inhibited.

However, usually, after the transition metal simple substance, complex and / or metal compound is suspended in the reaction solvent, after blending the Grignard reagent, the fullerene is blended, and then the R ¹⁰ introducing agent is blended. preferable. According to this procedure, at the stage of blending R ¹⁰ introducing agent, since the fullerene derivative R ²⁰ is added and the transition metal is believed to form an intermediate having a complex structure, at that stage R ¹⁰ It is effective to add an introduction agent.
Regarding the intermediate formed by the C ₆₀ derivative and / or C ₇₀ derivative and the copper metal, the "Quarterly chemical review 43 carbon third allotrope fullerene chemistry" 169-170 page, the estimated structure described Has been.

The temperature conditions during the reaction are not limited as long as the reaction proceeds, but in general, the temperature of the reaction system after adding the R ¹⁰ introducing agent to the reaction system is usually 0 ° C. or higher, preferably 15 ° C. or higher, Usually, it is desirable that the temperature is 100 ° C. or lower, preferably 70 ° C. or lower.
Although the reaction time is not limited, generally, after adding the R ¹⁰ introducing agent to the reaction system, it is usually 30 minutes or longer, preferably 2 hours or longer, and usually several tens of hours or shorter, preferably 10 hours or shorter. It is desirable to react.

The R ¹⁰ introduction agent is usually added to the reaction system when the fullerene conversion rate exceeds a predetermined value. In order to prevent oxidation of the product, deoxidation such as nitrogen bubbling or vacuum deaeration is performed. It is preferable to add to the reaction system after performing a gas operation.
In addition, the method currently reported by the above-mentioned patent document, a nonpatent literature, etc. can be employ | adopted for other operation regarding manufacture.

In the above reaction, when a compound in which a protecting group is introduced into the hydroxyl group of R ²⁰ is used as the Grignard reagent, the fullerene derivative of the present invention produced by the reaction is in a state in which the protecting group is introduced into the hydroxyl group of R ^20. (This may be referred to as “hydroxyl-protected fullerene derivative” hereinafter as appropriate). Therefore, in this case, a deprotecting agent corresponding to the type of protecting group is allowed to act on the obtained hydroxyl-protected fullerene derivative to remove the protecting group (this reaction is sometimes referred to as “deprotection reaction”). ), The intended fullerene derivative of the present invention can be produced. Under the present circumstances, only 1 type may be used for a deprotecting agent and it may use 2 or more types together by arbitrary combinations and a ratio.

For example, when the protecting group is a methyl group, examples of the deprotecting agent include boron tribromide, boron trichloride, aluminum trichloride, and trimethylsilyl iodide. Among these, boron tribromide and trimethylsilyl iodide are preferable from the viewpoint of reactivity. In addition, when handling of these deprotecting agents is difficult, a method of generating in situ may be used.
The amount of these deprotecting agents to be used is arbitrary as long as the above-mentioned protecting group can be removed, but it is usually at least 1 mol, preferably 1.2 times in proportion to the corresponding protecting group (methyl group). It is desirable that the amount be not less than mol, more preferably not less than 1.4 times mol, and usually not more than 10 times mol, preferably not more than 5 times mol, more preferably not more than 3 times mol. If the amount of the deprotecting agent used is too large, it may be disadvantageous in terms of production costs, and if the amount of the deprotecting agent used is too small, the reaction may not be completed. In addition, when using 2 or more types of deprotecting agents together, it is desirable for those total amount to satisfy the said range.

For example, when the protecting group is a tetrahydropyranyl group, examples of the deprotecting agent include paratoluenesulfonic acid, metatoluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, hydrochloric acid, sulfuric acid, and other acidic substances. It is done. Among these, paratoluenesulfonic acid and methanesulfonic acid are preferable from the viewpoint of reactivity.
The amount of these deprotecting agents used is arbitrary as long as the protecting group can be eliminated, but is usually 0.01 times mol or more, preferably in terms of the ratio to the corresponding protecting group (tetrahydropyranyl group). It is desirable that the amount be 0.03 times mole or more, usually 2 times mole or less, preferably 1 time mole or less. If the amount of the deprotecting agent used is too large, it may be disadvantageous in terms of production cost, or the contamination effect on the resulting fullerene derivative may be increased. If the amount of the deprotecting agent used is too small, the reaction may occur. The time may be longer. In addition, when using 2 or more types of deprotecting agents together, it is desirable for those total amount to satisfy the said range.

  The deprotection reaction is usually performed in a state where the hydroxyl-protected fullerene derivative is dissolved or suspended in an organic solvent. The organic solvent used for the reaction may be arbitrarily selected as long as it does not inhibit the deprotection reaction or cause an undesirable reaction. Specific examples of the organic solvent include halogenated hydrocarbons such as chlorobenzene, orthodichlorobenzene, trichlorobenzene, and methylene chloride; aromatic hydrocarbons such as toluene, xylene, and trimethylbenzene; alcoholic solvents such as methanol, ethanol, and isopropyl alcohol. Nitrile solvents such as acetonitrile and benzonitrile; Any one of these organic solvents may be used, or two or more thereof may be used in any combination and ratio.

  The amount of the organic solvent used for the hydroxyl-protected fullerene derivative is arbitrary, but the concentration of the hydroxyl-protected fullerene derivative in the organic solvent is usually 1 mg / mL or more, preferably 10 mg / mL or more, more preferably 15 mg / mL. In addition, it is desirable that the amount is usually 1000 mg / mL or less, preferably 500 mg / mL or less, more preferably 100 mg / mL or less.

In any deprotection reaction, the order of mixing the hydroxyl-protected fullerene derivative, the deprotecting agent, the organic solvent, etc. is not limited as long as the reaction proceeds. Furthermore, if deprotection reaction advances, reaction conditions are also arbitrary.
However, although the temperature condition varies greatly depending on the type of deprotection reaction, it is usually 0 ° C or higher, preferably 15 ° C or higher, and usually 180 ° C or lower, preferably 120 ° C or lower.
The reaction time is usually 30 minutes or longer, preferably 2 hours or longer, and usually several tens of hours or shorter, preferably 10 hours or shorter.

  After completion of the reaction, the produced fullerene derivative of the present invention is usually isolated from the reaction solution by a conventional method. The isolation operation varies depending on the type of each reaction. For example, the reaction solution is crystallized with a poor solvent such as hexane as it is, or the reaction solution is stopped by adding ion-exchanged water or an aqueous solution of sulfurous acid to the reaction solution. After extraction with a suitable solvent, the product can be isolated by liquid separation and evaporation of the solvent.

  The obtained fullerene derivative of the present invention may be purified by a technique such as high performance liquid chromatography (HPLC), silica gel column chromatography, alumina column chromatography, recrystallization or the like as necessary. The isolation yield is usually 60% or more, preferably 80% or more, as a consistent yield from fullerene, when carried out under the above-mentioned preferable reaction conditions.

The fullerene derivative of the present invention is usually a proton nuclear magnetic resonance spectrum method (hereinafter sometimes referred to as “ ¹ H-NMR” as appropriate) or a carbon nuclear magnetic resonance spectrum method (hereinafter referred to as “ ¹³ C-NMR” as appropriate). ), Infrared absorption spectroscopy (hereinafter sometimes referred to as “IR” as appropriate), mass spectrometry (hereinafter also referred to as “MS” as appropriate), and general organic analysis such as elemental analysis, Its structure can be confirmed. In addition, when the crystallinity of the fullerene derivative is good, the structure may be confirmed by an X-ray crystal diffraction method.

[3. Fullerene derivative solution]
The fullerene derivative of the present invention can be used for various applications described above by dissolving in a suitable solvent to form a solution. Hereinafter, the fullerene derivative solution of the present invention in which the fullerene derivative of the present invention is dissolved in a solvent is referred to as “the solution of the present invention” as appropriate.

  Although the kind of the solvent in the solution of the present invention is arbitrary, a preferred example includes an organic solvent. As the organic solvent, any organic solvent known so far can be used. Among these, since the fullerene derivative of the present invention has a hydroxyl group and therefore exhibits high solubility in a polar organic solvent, it is preferable to use a polar organic solvent as the solvent of the solution of the present invention.

The type of polar organic solvent is not limited, but examples include alcohols such as methanol, ethanol, and isopropanol; ketones such as acetone, methyl ethyl ketone, methyl isoamyl ketone, methyl amyl ketone, and cyclohexanone; methyl acetate, ethyl acetate, and propyl acetate , Esters (ester solvents) such as butyl acetate, methyl propionate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, and γ-butyrolactone; tetrahydrofuran, dioxane, anisole, ethylene glycol dimethyl ether, Ethers such as diethylene glycol dimethyl ether; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, Ether alcohols such as pyrene glycol monomethyl ether and 3-methoxy-3-methyl-1-butanol; ether esters (ester solvents) which are ester compounds of the ether alcohols and acids such as acetic acid; N, N-dimethyl Examples include amides such as formamide and N-methylpyrrolidone; nitriles such as acetonitrile and benzonitrile; dimethyl sulfoxide and the like.
Among them, ketones such as cyclohexanone and methyl amyl ketone and ester solvents are preferably used from the viewpoint of being often used for industrial applications, and in particular, propylene glycol-1-monomethyl ether-2-acetate (PGMEA). It is preferable to use a high boiling ester solvent such as ethyl lactate.

  An alkaline solvent is also preferably used as the solvent in the solution of the present invention. The type of the alkali solvent is not limited as long as the fullerene derivative of the present invention can be dissolved. Examples thereof include pyridine, piperidine, triethylamine, tri-n-propylamine, methyldiethylamine, 1,8-diazabicyclo- (5 , 4,0) -7-undecene, dimethylethanolamine, and other alkaline organic solvents; sodium hydroxide aqueous solution, lithium hydroxide aqueous solution, calcium hydroxide aqueous solution, sodium carbonate aqueous solution, lithium carbonate aqueous solution, calcium carbonate aqueous solution, ammonia aqueous solution, tetra Examples include alkaline aqueous solutions such as aqueous methylammonium hydroxide solution. In the case of an alkaline aqueous solution, the concentration of the solute is arbitrary.

  In the solution of the present invention, only one solvent may be used, or two or more solvents may be used in any combination and ratio. Therefore, as for the said polar organic solvent and alkali solvent, all may use only 1 type and may use 2 or more types together by arbitrary combinations and a ratio. Moreover, you may use both together.

  Furthermore, the ratio of the fullerene derivative of the present invention to the solvent in the solution of the present invention is arbitrary. Moreover, in the solution of the present invention, the fullerene derivative of the present invention is preferably completely dissolved in a solvent, but may be partially suspended without being dissolved or may be precipitated.

  As long as the excellent physical properties of the fullerene derivative of the present invention are not significantly impaired, the solution of the present invention may contain other components in addition to the fullerene derivative and the solvent of the present invention. Other components may contain only 1 type and may contain 2 or more types by arbitrary combinations and ratios.

  As long as the fullerene derivative of the present invention can be dissolved in a solvent, the method for preparing the solution of the present invention is not limited, but it can usually be prepared by a method of dissolving with stirring in a predetermined apparatus, a method of irradiating ultrasonic waves, or the like. . Further, the mixing order of the fullerene derivative of the present invention, the solvent, and other components used as necessary is not particularly limited.

  The solution of the present invention is usually prepared at about 25 ° C. from the viewpoint of stability and operability, but can be dissolved and stored while heating as long as it is below the boiling point of the solvent. Moreover, although the fullerene derivative of this invention may precipitate, it can also prepare and store under low temperature of 25 degrees C or less.

[4. Fullerene derivative film]
Since the fullerene derivative of the present invention exhibits high solubility in the above-described organic solvents, particularly ester solvents, ketone solvents, and ether solvents, the fullerene derivative solution is applied to an arbitrary substrate and dried by heating. Membranes can be manufactured.
The fullerene derivative solution used in this case may contain other arbitrary compounds in addition to the fullerene derivative and the organic solvent as long as the excellent physical properties of the fullerene derivative of the present invention are not significantly impaired.

As a method for applying the solution of the present invention, any method such as a spray method, a spin coating method, a dip coating method, or a roll coating method can be selected.
Further, the base material to be applied is not limited, and examples thereof include an organic film, a silicon substrate, a silicon film such as a polysilicon film, a silicon oxide film, and a silicon nitride film, and an inorganic film such as a metal wiring.

  In the heat drying treatment of the coating film, it is usually preferable to heat at 80 to 300 ° C. for 10 seconds to 300 seconds. Since the fullerene derivative of the present invention is excellent in thermal stability as compared with a normal organic compound, a stable film can be formed without thermal decomposition even in such heat drying treatment. Moreover, it is preferable to perform heating in air | atmosphere or inert gas atmosphere, such as argon and nitrogen.

  The film thickness of the fullerene derivative film of the present invention varies greatly depending on the application and cannot be uniformly limited, but is usually 10 nm or more, preferably 30 nm or more, and usually 1,000 nm or less, preferably 500 nm or less. More preferably, it is 300 nm or less.

  The fullerene derivative film of the present invention can form a uniform film, and the refractive index (n value) and extinction coefficient (k value) can be measured with a spectroscopic ellipsometer or the like. Moreover, the dielectric constant and reflectance of the fullerene derivative film of the present invention can be calculated using these measured values. These optical constants vary greatly depending on the use of the fullerene derivative film, and also in the same use, depending on the type of process and the type and amount of other components contained in the fullerene derivative film. Therefore, it is preferable to use for the use which can utilize effectively the outstanding physical property which the fullerene derivative film | membrane of this invention has. In particular, the fullerene derivative film of the present invention has a fullerene derivative, which is a component thereof, that retains a large amount of π-electron conjugation of the fullerene skeleton, and has introduced a hydrocarbon group having aromaticity as a substituent. Therefore, since high etching resistance can be expected, it is suitably used for photoresist applications.

  Among the above, the film containing the fullerene derivative of the present invention is characterized by a low k value at a wavelength of 193 nm, and is particularly suitably used for applications in which this physical property can be effectively utilized.

[5. Use of fullerene derivative, fullerene derivative solution and fullerene derivative film]
The fullerene derivative of the present invention, the solution of the present invention, and the fullerene derivative film can be used for the aforementioned applications.
Hereinafter, some examples of applications will be specifically described. However, the applications in which the function of the fullerene derivative of the present invention can be exhibited are not limited to the following descriptions.

[5-1. Photoresist application]
Conventionally, a photoresist is a composition in which a resin component such as a (meth) acrylic, polyhydroxystyrene or novolac resin as a film forming component is combined with an acid generator or a photosensitizer that generates an acid upon exposure. Widely used. Since the fullerene derivative of the present invention is usually highly soluble in an organic solvent used in a photoresist, it can be combined with the photoresist at a higher concentration without using a special solvent. Further, it is possible to form a resist film with a fullerene derivative alone.

  As described above, when the fullerene derivative of the present invention or the solution of the present invention is used in the field of photoresist, by having a fullerene skeleton, it has high heat resistance as a superaromatic molecule, high etching resistance, and edge roughness. It can be reduced and a high-resolution photoresist can be reproduced. Further, the resist film formed using the fullerene derivative of the present invention or the solution of the present invention also has a function as an antireflection film as apparent from the absorption spectrum. It is expected to exhibit an excellent function as a coating type mask material (hard mask). In particular, since the film containing the fullerene derivative of the present invention has a low k value at a wavelength of 193 nm, it can be suitably used for an ArF excimer laser.

[5-2. Semiconductor manufacturing applications]
In the field of semiconductor manufacturing and the like, a nanoimprint method has been studied as a method for forming a fine pattern of 500 μm or less with high production efficiency. The nanoimprint method is a method for forming a fine pattern in which a pattern of a mold having a fine pattern is transferred to a transfer layer.

  Examples of such a nanoimprint method include a step of heating and softening a transfer layer made of a thermoplastic polymer, a step of pressing the transfer layer and a mold to form a pattern of the mold on the transfer layer, and a mold. A method of sequentially separating the transfer layer from the transfer layer; a step of bringing a transfer layer made of a curable monomer into contact with the mold; a step of curing the curable monomer; and a mold from a cured product of the curable monomer And a method of sequentially performing the step of releasing the components. The fullerene derivative of the present invention is usually filled in the thermoplastic polymer at a high concentration without using a special solvent because of its high solubility in the organic solvent used for the thermoplastic polymer and curable material. Is possible.

  As described above, when the fullerene derivative of the present invention or the solution of the present invention is used in the nanoimprint method, the solubility of the fullerene derivative of the present invention in an organic solvent is high, so the fullerene derivative of the present invention in the thermoplastic polymer. Aggregation is suppressed, resulting in molecular dispersion. For this reason, it is possible to realize high resolution. Furthermore, by using the fullerene derivative of the present invention or the solution of the present invention for the nanoimprint method, it is possible to improve the mechanical strength, heat resistance and etching resistance of the transfer layer. Significant improvement is possible.

[5-3. Low dielectric constant insulation materials]
In recent years, resin thin film wiring suitable for high-density and fine multilayer wiring using a resin thin film as an interlayer insulating film has been applied to a circuit board for a central processing unit (CPU) of a computer. In order to realize a computer having a higher processing speed in the future, development of a low dielectric constant insulating material that utilizes high-density and delicate multilayer wiring and is suitable for high-speed signal propagation is required. The fullerene derivative of the present invention can be complexed with other materials at a higher concentration without using a special solvent because the fullerene derivative of the present invention usually has high solubility in an organic solvent used for the above-mentioned applications. It is also possible to form a film with a fullerene derivative alone. At this time, the fullerene derivative of the present invention retains the properties of high resistance and low dielectric constant inherently possessed by the fullerene structure, and has an effect of improving mechanical strength as a filler when used in combination. As a result, it is possible to realize an interlayer insulating film having a low dielectric constant with an excellent performance which has not been achieved conventionally.

[5-4. Solar cell application]
Although organic solar cells have many advantages over silicon-based inorganic solar cells, the energy conversion efficiency is low and the practical level has not been sufficiently achieved. In order to overcome this problem, a bulk heterojunction organic solar cell having an active layer in which a conductive polymer as an electron donor and a fullerene and a fullerene derivative as an electron acceptor are recently proposed has been proposed. Yes. In this bulk heterojunction type organic solar cell, the conductive polymer and the fullerene derivative are mixed at the molecular level, and as a result, a very large interface is successfully created, and the conversion efficiency is greatly improved.

Since the fullerene derivative of the present invention has high solubility in an organic solvent used in the above-mentioned applications, it is easy to form an efficient bulk heterojunction structure with a p-type semiconductor. The fullerene derivative of the present invention essentially retains the properties of fullerene as an n-type semiconductor.
For these reasons, if the fullerene derivative of the present invention or the solution of the present invention is used, an extremely high performance organic solar cell can be realized. Furthermore, by utilizing this high solubility, it is possible to control layer separation from electron donor layers such as conductive polymers, and to control morphology such as alignment orientation and fine packing of derivative molecules, thereby improving characteristics. In addition, it provides great flexibility in device design. Also, in terms of production, it is possible to easily realize a large area at low cost by ordinary printing methods, ink jet printing, and spraying.

[5-5. Semiconductor application]
Research has been made on the use of fullerenes and fullerene derivatives as organic materials for field-effect transistors that can be expected to be applied to optical sensors, rectifiers, and the like. Generally, when a field effect transistor is manufactured using fullerene and a fullerene derivative as a semiconductor, it is known that the field effect transistor functions as an n-type transistor.
The fullerene derivative of the present invention has a high solubility in an organic solvent used in the above-mentioned applications, and therefore, film formation by coating is easy, and the essential properties of fullerene as an n-type semiconductor are retained. . Thereby, the fullerene derivative of the present invention can be expected as a low-cost, high-performance organic semiconductor.

[5-6: Application as raw material intermediate]
Using the fullerene derivative of the present invention as a starting material, a fullerene derivative having a new function can be produced through a step of introducing a specific organic group (protecting group) into the hydroxyl group. Hereinafter, representative examples of the method for introducing the organic group will be described, but the present invention is not limited to the following examples.

Specific methods for introducing an organic group vary depending on the type of the organic group to be introduced. For example, the following may be mentioned.
(1) The hydroxyl group-containing fullerene derivative of the present invention is esterified by reacting with an esterifying agent.
(2) The hydroxyl group-containing fullerene derivative of the present invention is reacted with a carbonating agent to be carbonated.
(3) The hydroxyl group-containing fullerene derivative of the present invention is etherified by reacting with an etherifying agent.
(4) The hydroxyl group-containing fullerene derivative of the present invention is reacted with a urethanizing agent to urethanize.

  As for the conditions for introducing the organic group into the fullerene derivative of the present invention including the above methods (1) to (4), JP-A-2006-56878 and other existing methods can be referred to.

  EXAMPLES Hereinafter, the present invention will be further described with reference to examples. However, the present invention is not limited to the following examples, and can be arbitrarily modified without departing from the gist of the present invention. . In the description of the present specification, THF represents tetrahydrofuran, ODCB represents orthodichlorobenzene, and DMSO represents dimethyl sulfoxide. Further, Me represents a methyl group, Np represents a naphthyl group, and THP represents a tetrahydropyranyl group.

{Production and evaluation of fullerene derivatives}
[Example 1: Production of C ₆₀ {β- (6-OH-C ₁₀ H ₆ )} ₅ (—CH ₃ )]
A THF suspension (84 mL) of a copper (I) dimethyl sulfide complex (9.72 g, 47.3 mmol) was cooled to 5 ° C., and then the Grignard reagent 6-synthesized from 2-bromo-6-methoxynaphthalene was used. OCH ₃ —C ₁₀ H ₆ MgBr / THF solution (1 mol / L; 51 mL) was added, and the temperature was raised to 25 ° C. Thereto, an ODCB solution (135 mL) of C ₆₀ (3.0 g, 4.17 mmol) was added and stirred for 2 hours. To this, MeI (3 mL, 48 mmol) was added and further stirred for 8 hours. The reaction solution was filtered to remove THF, diluted with toluene, and subjected to silica column chromatography (developing solution: toluene and ethyl acetate). The solution was concentrated, crystallized with methanol (500 mL), and vacuum-dried at 50 ° C., whereby C ₆₀ {β- (6-OCH ₃ —C ₁₀ H ₆ )} ₅ (—CH ₃ ) was converted to orange. Obtained as the product of a colored solid (6.87 g, 4.52 mmol, 108.5% yield). The product contained 11% by weight of ODCB as a solvent.

Next, an orthodichlorobenzene solution of C ₆₀ {β- (6-OCH ₃ -C ₁₀ H ₆ )} ₅ (—CH ₃ ) (4.00 g, 2.63 mmol) containing 11 wt% of ODCB solvent. (120 mL) was prepared, and after cooling to 5 ° C., a BBr ₃ -methylene chloride solution (1.0 mol / L, 16.0 mL) was added, and the temperature was raised to 25 ° C. After stirring at room temperature for 10 hours, the reaction was stopped with ion-exchanged water (100 mL), ethyl acetate (200 mL) was added, and the mixture was extracted with a separatory funnel. The organic layer was washed twice with ion exchange water, dried over magnesium sulfate, and then filtered. The solution was concentrated, crystallized with hexane (300 mL), and vacuum-dried at 180 ° C. for 5 hours, whereby the title compound C ₆₀ {β- (6-OH—C ₁₀ H ₆ )} ₅ (− CH ₃ ) was obtained as the product of an orange solid (2.80 g, 1.93 mmol, 73.4% yield, consistent yield 79.6% from C ₆₀ ).

The obtained product was measured by ¹ H-NMR and HPLC. ¹ H-NMR was measured at 400 MHz using DMSO-d ₆ as a solvent. In HPLC, a 0.5 mg / mL methanol solution was prepared and measured under the following measurement conditions.

Column type: ODS
Column size: 150mm x 4.6mmφ
Eluent: Toluene / methanol = 2/8
Detector: UV290nm

  As a result of HPLC measurement, it was observed at 94.6 (Area%) at a retention time of 6.42 min.

Moreover, the measurement result of < ¹ > H-NMR was as follows.
[ ¹ H-NMR (DMSO-d ₆ , 400 MHz)]
9.85 ppm (s, OH, 1 H), 9.84 ppm (s, OH, 1 H), 9.81 ppm (s, OH, 1 H), 9.76 ppm (s, OH, 1 H), 9.70 ppm (s, OH, 1H), 8.2 to 8.4 ppm (m, Np, 4H), 7.8 to 8.0 ppm (m, Np, 8H), 7.6 to 7.7 ppm (m, Np, 4H), 7.54 ppm (d, Np, 1H), 7.24-7.35 ppm (m, Np, 2H), 7.0-7.2 ppm (m, Np, 9H), 6.90 ppm (m, Np, 2H) ), 1.62 ppm (s, C ₆₀ Me, 3H)

From the above results, it was confirmed that the obtained product was the title compound C ₆₀ {β- (6-OH—C ₁₀ H ₆ )} ₅ (—CH ₃ ).

  Furthermore, the obtained product was dissolved in propylene glycol-1-monomethyl ether-2-acetate (PGMEA) at 25 ° C. and normal pressure, and the solubility was measured. The results are shown in Table 1 below.

  Further, a PGMEA solution of the obtained fullerene derivative was prepared (5% by weight), and filtered through a 0.2 μm fluororesin filter manufactured by Advantech, thereby preparing a coating solution. The solution was applied on a silicon substrate and rotated at a rotation speed of 500 rpm for 10 seconds and then at 1500 rpm for 40 seconds. Thereafter, contact baking was performed at 100 ° C. for 1 minute to form a thin film having a thickness of 80 nm. At this point, the film coatability was evaluated by visual observation from the mirror surface state.

  This is described in J. Org. A. A refractive index (n value) and an extinction coefficient (k value) at a wavelength of 193 to 1680 nm were obtained with a spectroscopic ellipsometer (M-2000) having a variable incident angle from Woollam. In addition, the dielectric constant (only the real part is described) and the reflectance at the incident angle of 45 degrees (193 nm data is described as 195 nm data. The unit is an absolute value display of 0 to 1) were obtained by calculation. The results are shown in Tables 1 and 3. The wavelength spectrum of the refractive index and extinction coefficient is shown in FIG.

Furthermore, TG-DTA of the obtained product was measured. The result is shown in FIG. TG-DTA was measured under the following conditions.
Sample mass: 5.050 mg
Gas flow rate: Nitrogen gas, 200 mL / min
Bread: Pt
Temperature increase rate: 10 ° C / min
Measurement upper limit temperature: 30 ° C to 900 ° C

Further, a PGMEA solution of the obtained fullerene derivative was prepared (concentration 5% by weight), stirred for 1 hour or until there was no undissolved matter, and then filtered through a 0.2 μm PTFE filter. Next, the above solution was spin-coated on a quartz substrate (disk shape) of 30 mmφ (thickness 2 mm) (the number of revolutions was initially 500 rpm for 10 sec and the latter half at 3000 rpm for 40 sec). Thereafter, the solvent was removed by drying at 40 ° C. for 2 hours using a vacuum dryer.
In order to measure the film thickness of the fullerene derivative thin film thus formed and use it for correction, a part of the film is peeled off with acetone, and the step between the peeled part and the healthy part is measured with a step gauge (alfa step 500, manufactured by Tencor). did. Next, the quartz plate on which the film was formed was measured with a visible / ultraviolet spectrophotometer (manufactured by Shimadzu Corporation, UV-17010) in a wavelength range of 190 nm to 1500 nm with a double beam system, and the light source was a halogen lamp or deuterium lamp. The switching method and the detector were measured with a silicon photodiode. Using the measured film thickness, the data was corrected to absorbance data of 50 nm film thickness. The result is shown in FIG. FIG. 3 shows that this fullerene derivative has a specific absorption spectrum in a film state.

Separately, a PGMEA solution of the obtained fullerene derivative was prepared (concentration: 5% by weight), stirred for 1 hour or until there was no undissolved material, and then filtered through a 0.2 μm PTFE filter. Next, the above solution was spin-coated on a 4-inch Si wafer (the number of revolutions was initially 10 rpm at 500 rpm and 40 sec at 1500 rpm in the second half). Thereafter, a film was formed by contact baking at 100 ° C. for 60 seconds on a hot plate. Ultrapure water was dropped on the film, and the contact angle was measured with a contact angle meter (CA-X150 type manufactured by Kyowa Interface Science Co., Ltd.). For comparison, the contact angle of a 4-inch Si wafer was also measured. The measurement was repeated 2 times under the condition 1 minute after dropping, and the average value was evaluated.
As a result, the contact angle of the Si wafer was 41.0 °, whereas the contact angle of the thermoset film of the obtained fullerene derivative was 37.7 °, confirming that it has a specific contact angle. It was.

[Example 2: Production of C ₆₀ (β-6-OH—C ₁₀ H ₆ ) ₅ (—CH ₂ CH═CH ₂ )]
After cooling a THF suspension (168 mL) of copper (I) bromide dimethyl sulfide complex (19.44 g, 94.6 mmol) to 5 ° C., Grignard synthesized from a raw material in which 2-bromo-6-naphthol was THP protected. A 6-OTHP-C ₁₀ H ₆ MgBr / THF solution (1 mol / L; 102 mL) of the reagent was added, and the temperature was raised to 25 ° C. An ODCB solution (270 mL) of C ₆₀ (6.0 g, 8.34 mmol) was added thereto and stirred for 4 hours. Allyl bromide (10 mL, 116.6 mmol) was added thereto, and the mixture was further stirred for 12 hours. The reaction solution was filtered to remove THF, diluted with toluene, and subjected to alumina column chromatography (developing solution: toluene). The solution was concentrated, crystallized with hexane (500 mL) and methanol (700 mL), and vacuum-dried at 50 ° C., whereby C ₆₀ (β-6-OTHP-C ₁₀ H ₆ ) ₅ (—CH ₂ CH = CH ₂ ) was obtained as the product of an orange solid (15.16 g, 8.00 mmol, 95.9% yield).

Next, a mixed solution of C ₆₀ (β-6-OTHP-C ₁₀ H ₆ ) ₅ (—CH ₂ CH═CH ₂ ) (5.00 g, 2.64 mmol) in methanol (63 mL) and methylene chloride (63 mL) was added. Prepared, added methanesulfonic acid (26 μL), and stirred at room temperature for 3 hours. The reaction solution was diluted with methylene chloride (30 mL), and then crystallized with hexane (500 mL). Thereafter, by performing 50 ° C. vacuum dried for 3 hours, the title compound _{C 60 (β-6-OH} -C 10 H 6) 5 (-CH 2 CH = CH 2) an orange solid (3.32 g, 2. 25 mmol, 85.2% _yield, as a product of consistent yield 81.7%) of the _{C 60.}

In the same manner as in Example 1, the obtained product was measured by HPLC and ¹ H-NMR (400 MHz).

  As a result of HPLC measurement, a retention time of 6.2.3 min was observed at 92.3 (Area%).

Moreover, the measurement result of < ¹ > H-NMR was as follows.
[ ¹ H-NMR (DMSO-d ₆ , 400 MHz)]
9.80 ppm (brs, OH, 5H), 8.50 ppm (d, Np, 2H), 8.28 ppm (d, Np, 2H), 7.8-8.1 ppm (m, Np, 4H), 7. 2 to 7.8 ppm (m, Np, 12H), 7.0 to 7.2 ppm (m, Np, 10H), 6.21 ppm (m, —CH ₂ —CH═CH ₂ , 1H), 5.53 ppm ( m, —CH ₂ —CH═CH ₂ , 1H), 4.90 ppm (m, —CH ₂ —CH═CH ₂ , 1H), 2.35 ppm (m, —CH ₂ —CH═CH ₂ , 1H), 2.00 ppm (m, —CH ₂ —CH═CH ₂ , 1H)

In addition to the above results, since the target molecular weight (M: 1476) was confirmed by HPLC-MS, the obtained product was obtained as the title compound C ₆₀ (β-6-OH—C ₁₀ H ₆ ) ₅ (—CH ₂ CH = CH ₂ ).
Further, the solubility of the obtained product was measured in the same manner as in Example 1. The results are shown in Table 1 below.
Further, a thin film having a thickness of 80 nm was formed on the obtained product in the same manner as in Example 1, and the refractive index, extinction coefficient, reflectance, and dielectric constant were determined in the same manner as in Example 1. The results are shown in Tables 1 and 4. Moreover, the wavelength spectrum of a refractive index and an extinction coefficient is shown in FIG.

[Example 3: Production of C ₆₀ (β-6-OH—C ₁₀ H ₆ ) ₅ (—CH ₂ CH═CH (CH ₃ ))]
After cooling a THF (56 mL) suspension of copper (I) dimethyl sulfide complex (6.48 g, 31.5 mmol) to 5 ° C., Grignard synthesized from a THP-protected raw material of 2-bromo-6-naphthol. A 6-OTHP-C ₁₀ H ₆ MgBr / THF solution (1 mol / L; 34 mL) of the reagent was added, and the temperature was raised to 25 ° C. An ODCB solution (90 mL) of C ₆₀ (2.0 g, 2.78 mmol) was added thereto and stirred for 4 hours. Crotyl bromide (10 mL, 98 mmol) was added thereto, and the mixture was further stirred for 10 hours. The reaction solution was filtered to remove THF, diluted with toluene, and subjected to alumina column chromatography (developing solution: toluene). The solution was concentrated, crystallized with hexane (200 mL) and methanol (300 mL), and vacuum-dried at 50 ° C., whereby C ₆₀ (β-6-OTHP-C ₁₀ H ₆ ) ₅ (—CH ₂ CH = CH (CH ₃ )) was obtained as the product of an orange solid (4.99 g, 2.61 mmol, 93.9% yield).

Next, C ₆₀ (β-6-OTHP-C ₁₀ H ₆ ) ₅ (—CH ₂ CH═CH (CH ₃ )) (4.00 g, 2.09 mmol) in methanol (50 mL), methylene chloride (50 mL) A mixed solution was prepared, methanesulfonic acid (21 μL) was added, and the mixture was stirred at room temperature for 3 hours. The reaction solution was diluted with methylene chloride (30 mL), and then crystallized with hexane (500 mL). Then, the title compound C ₆₀ (β-6-OH—C ₁₀ H ₆ ) ₅ (—CH ₂ CH═CH (CH ₃ )) was converted to an orange solid (2.42 g) by vacuum drying at 50 ° C. for 3 hours. to give 1.62 mmol, 77.5% _yield, as part of product yield 72.8%) of the _{C 60.}

In the same manner as in Example 1, the obtained product was measured by HPLC and ¹ H-NMR (400 MHz).

  As a result of HPLC measurement, the retention time was observed at 96.7 (Area%) at 6.44 min.

Moreover, the measurement result of < ¹ > H-NMR was as follows.
[ ¹ H-NMR (DMSO-d ₆ , 400 MHz)]
9.85 ppm (brs, OH, 3H), 9.75 ppm (brs, OH, 2H), 8.30 ppm (m, Np, 4H), 7.9 to 8.1 ppm (m, Np, 4H), 7. 6 to 7.8 ppm (m, Np, 4H), 7.3 to 7.6 ppm (m, Np, 8H), 6.9 to 7.3 ppm (m, Np, 10H), 5.70 ppm (m, − _{CH 2 -CH = CH (CH 3} ), 1H), 5.12ppm (m, -CH 2 -CH = CH (CH 3), 1H), 2.39ppm (m, -CH 2 -CH = CH (CH _{3), 1H), 2.05ppm (} m, -CH 2 -CH = CH (CH 3), 1H), 1.55ppm (d, -CH 2 -CH = CH (CH 3), 3H)

From the above results, it was confirmed that the obtained product was the title compound C ₆₀ (β-6-OH—C ₁₀ H ₆ ) ₅ (—CH ₂ CH═CH (CH ₃ )).
Further, the solubility of the obtained product was measured in the same manner as in Example 1. The results are shown in Table 1 below.
Further, a thin film having a thickness of 80 nm was formed on the obtained product in the same manner as in Example 1, and the refractive index, extinction coefficient, dielectric constant, and reflectance were determined in the same manner as in Example 1. The results are shown in Table 1 and Table 5. Moreover, the wavelength spectrum of a refractive index and an extinction coefficient is shown in FIG.

[Example 4: Production of C ₆₀ (β-6-OH-C ₁₀ H ₆ ) ₁₀ (—CH ₃ ) ₂ ]
A THF suspension (88 mL) of a copper (I) bromide dimethyl sulfide complex (17.28 g, 84.1 mmol) was cooled to 5 ° C., and then the Grignard reagent synthesized from 2-bromo-6-methoxynaphthalene OCH ₃ —C ₁₀ H ₆ MgBr / THF solution (1 mol / L; 90 mL) was added, and the temperature was raised to 25 ° C. Thereto was added dehydrated pyridine (68 mL), and the mixture was further stirred for 20 minutes. Next, an ODCB solution (80 mL) of C ₆₀ (2.0 g, 2.78 mmol) was added, and the mixture was stirred at 25 ° C. for 1 hour, and then stirred at 40 ° C. for 24 hours. To this, MeI (15 mL, 240 mmol) was added and stirred for another 12 hours. The reaction solution was filtered to remove THF, diluted with toluene, and subjected to silica column chromatography (developing solution: toluene and ethyl acetate). The solution was concentrated, crystallized with methanol (800 mL), and vacuum-dried at 50 ° C., whereby C ₆₀ (β-6-OCH ₃ —C ₁₀ H ₆ ) ₁₀ (—CH ₃ ) ₂ was converted into a yellow solid. Obtained as the product (7.06 g; 109.6%).

Next, an orthodichlorobenzene solution (80 mL) of C ₆₀ (β-6-OCH ₃ —C ₁₀ H ₆ ) ₁₀ (—CH ₃ ) ₂ (2.00 g, 0.86 mmol) was prepared and cooled to 5 ° C. After that, BBr ₃ -methylene chloride solution (1.0 mol / L, 13.0 mL) was added, and the temperature was raised to 25 ° C. After stirring at room temperature for 10 hours, the reaction was stopped with ion-exchanged water (100 mL), ethyl acetate (200 mL) was added, and the mixture was extracted with a separatory funnel. The organic layer was washed twice with ion exchange water, dried over magnesium sulfate, and then filtered. The solution was concentrated, crystallized with hexane (300 mL), and vacuum-dried at 50 ° C. for 5 hours, whereby the title compound C ₆₀ (β-6-OH—C ₁₀ H ₆ ) ₁₀ (—CH _{3 2} was obtained as the product of a yellow solid (1.70 g, 0.78 mmol, 90.5% yield, consistent yield 99.2% from C ₆₀ ).

The obtained product was measured by HPLC and ¹ H-NMR (400 MHz) in the same manner as in Example 1 except that the HPLC eluent ratio was changed to toluene / methanol = 5/95.

  As a result of HPLC measurement, the retention time was observed at 29.4 (Area%) at 1.96 min, 36.1 (Area%) at 3.40 min, and 34.5 (Area%) at 4.03 min. As a result of LC-MS measurement, these three peaks were all 2179.6, confirming the isomer mixture of the title compound.

Moreover, the measurement result of < ¹ > H-NMR was as follows.
[ ¹ H-NMR (DMSO-d ₆ , 400 MHz)]
9.50~9.80ppm (brs, OH, 10H) , 8.6~6.5ppm (m, Np, 60H), 1.80ppm (s, C 60 Me 2, 6H)

From the above results, it was confirmed that the obtained product was a mixture of positional isomers of the title compound C ₆₀ (β-6-OH—C ₁₀ H ₆ ) ₁₀ (—CH ₃ ) ₂ .
Further, the solubility of the obtained product was measured in the same manner as in Example 1. The results are shown in Table 1 below.
Further, for the obtained product, a thin film having a thickness of 80 nm was formed in the same manner as in Example 1, and the refractive index and extinction coefficient were determined in the same manner as in Example 1. The results are shown in Table 1 and Table 6. Moreover, the wavelength spectrum of a refractive index and an extinction coefficient is shown in FIG.

[Example 5: Mixed fullerene (mixture of C ₆₀ : 64.5 wt%, C ₇₀ : 23.8 wt%, and C ₇₀ or higher higher fullerene: 11.6 wt%) as a raw material) Body production]
A THF (75 mL) suspension of copper (I) bromide dimethyl sulfide complex (10.3 g, 50.0 mmol) was cooled to 5 ° C., and then the Grignard reagent synthesized from 2-bromo-6-methoxynaphthalene 6- OCH ₃ —C ₁₀ H ₆ MgBr / THF solution (1 mol / L; 50 mL) was added, and the temperature was raised to 25 ° C. An ODCB solution (135 mL) of mixed fullerene (3.0 g) containing C ₆₀ , C ₇₀ and higher-order fullerene of C ₇₀ or more was added thereto, and the mixture was stirred at 40 ° C. for 3 hours. To this, MeI (5.2 mL, 83 mmol) was added and further stirred for 8 hours. The reaction solution was filtered to remove THF, diluted with toluene, and subjected to silica column chromatography (developing solution: toluene and ethyl acetate). The solution is concentrated, crystallized with methanol (500 mL), and vacuum-dried at 50 ° C. to contain C ₆₀ {β- (6-OCH ₃ —C ₁₀ H ₆ )} ₅ (—CH ₃ ). The fullerene derivative mixture was obtained as the product of a brown solid (6.27 g).

Next, an orthodichlorobenzene solution (40 mL) of the fullerene derivative mixture (1.01 g) containing C ₆₀ {β- (6-OCH ₃ —C ₁₀ H ₆ )} ₅ (—CH ₃ ) obtained was prepared. After cooling to 5 ° C., a BBr ₃ -methylene chloride solution (1.0 mol / L, 10.0 mL) was added, and the temperature was raised to 25 ° C. After stirring at room temperature for 18 hours, the reaction was stopped with ion-exchanged water (100 mL), ethyl acetate (260 mL) was added, and the mixture was extracted with a separatory funnel. The organic layer was washed twice with ion exchange water, dried over magnesium sulfate, and then filtered. The solution was concentrated, crystallized with hexane (60 mL), and vacuum-dried at 50 ° C. for 3 hours to obtain C ₆₀ {β- (6-OH—C ₁₀ H ₆ )} ₅ (—CH ₃ ). Obtained as a product of a brown solid (707 mg) of a fullerene derivative mixture containing.

The obtained product was measured by ¹ H-NMR and HPLC. ¹ H-NMR was measured at 400 MHz using DMSO-d ₆ as a solvent. In HPLC, a 0.5 mg / mL methanol solution was prepared and measured under the following measurement conditions.

Column type: ODS
Column size: 150mm x 4.6mmφ
Eluent: toluene / methanol = 2/8 (toluene after 25 minutes by gradient method)
/ Methanol = 55/45)
Detector: UV290nm

As a result of HPLC measurement, C ₆₀ {β- (6-OH—C ₁₀ H ₆ )} ₅ (—CH ₃ ) at retention time 5.78 min at 78.5 (Area%), and 3.3 at 11.30 min. C ₇₀ {β- (6-OH—C ₁₀ H ₆ )} ₃ (—CH ₃ ) was observed at (Area%). These two peaks were identified by LC-MS measurement.

Moreover, the measurement result of < ¹ > H-NMR was as follows.
[ ¹ H-NMR (DMSO-d ₆ , 400 MHz)]
9.89 ppm (m, OH, 5H), 6.94 to 7.92 ppm (m, Np, 30H), 1.62 ppm (s, C ₆₀ Me, 3H)

From the above results, the obtained products were C ₆₀ {β- (6-OH—C ₁₀ H ₆ )} ₅ (—CH ₃ ) and C ₇₀ {β- (6-OH—C ₁₀ H ₆ )}. It was confirmed to be a fullerene derivative mixture containing ₃ (—CH ₃ ).
Further, the solubility of the obtained product was measured in the same manner as in Example 1. The results are shown in Table 1 below.
Further, for the obtained product, a thin film having a thickness of 80 nm was formed in the same manner as in Example 1, and the refractive index and extinction coefficient were determined in the same manner as in Example 1. The results are shown in Table 1 and Table 7. Moreover, the wavelength spectrum of a refractive index and an extinction coefficient is shown in FIG.

[Comparative Example 1: Production of C ₆₀ (3-OH—C ₆ H ₄ ) ₅ (—CH ₃ )]
After cooling a THF (112 mL) suspension of copper (I) dimethyl sulfide complex (12.96 g, 63.0 mmol) to 5 ° C., a 3-OCH ₃ —C ₆ H ₄ MgBr / THF solution (1 mol / L; 68 mL) was added and the temperature was raised to 25 ° C. An ODCB solution (180 mL) of C ₆₀ (4.0 g, 5.56 mmol) was added thereto and stirred for 2 hours. Thereto was added methyl iodide (8 mL, 129 mmol), and the mixture was further stirred for 8 hours. The reaction solution was filtered to remove THF, diluted with toluene, and subjected to silica column chromatography (developing solution: toluene, ethyl acetate). The solution was concentrated, crystallized with methanol (600 mL) and hexane (100 mL), and vacuum-dried at 50 ° C., whereby C ₆₀ (3-OCH ₃ —C ₆ H ₄ ) ₅ (—CH ₃ ) was obtained. Obtained as the product of an orange solid (6.58 g, 5.18 mmol, 93.3% yield).

Next, an ODCB (60 mL) solution of C ₆₀ (3-OCH ₃ —C ₆ H ₄ ) ₅ (—CH ₃ ) (1.50 g, 1.18 mmol) was prepared, cooled to 5 ° C., and then BBr ₃ A methylene chloride solution (1 mol / L; 9 mL) was added, and the mixture was stirred at room temperature for 8 hours. The resulting reaction solution was cooled to 5 ° C., quenched with ion exchange water (20 mL), and extracted with ethyl acetate (100 mL). The organic phase was washed twice with ion-exchanged water, dried over magnesium sulfate, and the solution was concentrated and crystallized from hexane (300 mL). Then, C ₆₀ (3-OH—C ₆ H ₄ ) ₅ (—CH ₃ ) was converted into an orange solid (1.21 g, 1.01 mmol, yield 85.3%) by performing vacuum drying at 50 ° C. for 3 hours. , A consistent yield of 79.6% from C ₆₀ ).

In the same manner as in Example 1, the obtained product was measured by HPLC and ¹ H-NMR (400 MHz).

  As a result of HPLC measurement, it was observed at 96.8 (Area%) at a retention time of 2.89 min.

Moreover, the measurement result of < ¹ > H-NMR was as follows.
[ ¹ H-NMR (DMSO-d ₆ , 400 MHz)]
9.58 ppm (s, OH, 1H), 9.55 ppm (s, OH, 2H), 9.49 ppm (s, OH, 1H), 9.40 ppm (s, OH, 1H), 7.30 ppm (m, Ph-OH, 6H), 7.20 ppm (m, Ph-OH, 6H), 6.93 ppm (m, Ph-OH, 1H), 6.75 ppm (m, Ph-OH, 4H), 6.60 ppm ( m, Ph-OH, 3H) , 1.73ppm (brs, CH 3, 3H)

From the above results, it was confirmed that the obtained product was the title compound C ₆₀ (3-OH—C ₆ H ₄ ) ₅ (—CH ₃ ).
Further, the solubility of the obtained product was measured in the same manner as in Example 1. The results are shown in Table 1 below.

  Further, a PGMEA solution of the obtained fullerene derivative was prepared (5% by weight), and a film was formed in the same manner as in Example 1. Moreover, the optical data of the film | membrane obtained like Example 1 were calculated | required. The results are shown in Table 1.

  In addition, the fullerene derivative of this invention shows high solubility also to solvents other than PGMEA. As an example, Table 2 shows the comparison results of the solubility of the fullerene derivative of Example 1 and the fullerene derivative of Comparative Example 1 in ethyl lactate (EL), propylene glycol monomethyl ether (PGME), methyl ethyl ketone (MEK), and cyclohexanone (CHN). Show.

  Table 3 shows the optical constants of the fullerene derivative film produced in Example 1.

  Table 4 shows the optical constants of the fullerene derivative film produced in Example 2.

  Table 5 shows the optical constants of the fullerene derivative film produced in Example 3.

  Table 6 shows the optical constants of the fullerene derivative film produced in Example 4.

  Table 7 shows the optical constants of the fullerene derivative film produced in Example 5.

{Preparation and evaluation of resists using fullerene derivatives}
[Example 6]
Using the fullerene derivative obtained in Example 1, a resist composition was prepared by the following procedure.
(I) OEBR-1000LB (manufactured by Tokyo Ohka Kogyo Co., Ltd.), which is a polymethyl methacrylate-based positive electron beam resist, was diluted twice with ethyl lactate thinner.
(Ii) The fullerene derivative obtained in Example 1 was added so that it might become 5 weight% with respect to solid content of OEBR-1000LB, and it stirred with the stirrer overnight.
(Iii) After stirring, the mixture was filtered through a filter having a pore diameter of 0.1 μm to obtain a resist composition.

[Example 7]
A resist composition was prepared in the same manner as in Example 6 except that the fullerene derivative used in resist preparation was the same as that obtained in Example 4.

[Example 8]
A resist composition was prepared in the same manner as in Example 6 except that the fullerene derivative used in resist preparation was the same as that obtained in Example 5.

[Comparative Example 2]
A resist composition was prepared in the same manner as in Example 6 without adding the fullerene derivative.

[Evaluation of etching resistance]
A resist film was formed by the following procedure, and its etching resistance was evaluated.
(1) Each of the resist compositions prepared in Examples 6 to 8 and Comparative Example 2 was spin-coated on a Si substrate so as to have a thickness of 100 nm (coating process), followed by heat treatment at 170 ° C. for 60 minutes. (Heating step).
(2) EB exposure apparatus: JBX-6000FS (manufactured by JEOL Ltd.) was used for exposure at an acceleration voltage of 50 kV (exposure process).
(3) Xylene was used as a developing solution and immersed in this for 45 seconds (developing step). Thereafter, IPA (isopropyl alcohol) was used as a rinsing solution, and the developer was rinsed off by immersing in IPA (30 seconds).
(4) After pattern formation, the step between the pattern and the Si substrate was measured. The measured level difference was defined as film thickness A (resist film thickness).
(5) A sample was prepared for each required time and etched according to the following procedure.
<RIE etching using CF ₄ gas>
Equipment: RIE-10NR manufactured by Samco International
Etching conditions: CF ₄ , 50 W, 70 sccm, 20 Pa
Etching time: 0 seconds, 60 seconds, 120 seconds, 180 seconds, 240 seconds, 300 seconds Film loss measurement: Alpha step 500 manufactured by KLA Tencor
(6) The level difference between the pattern and the Si substrate was measured. The measured step size was defined as film thickness B.
(7) Ashing was performed as follows, and the level difference between the Si substrate that had been patterned after the ashing and the Si substrate in the non-patterned part was measured. The measured step size was defined as film thickness C.
The ashing was performed as follows.
<Resist stripping by O ₂ ashing>
Equipment: RIE-10NR manufactured by Samco International
Ashing conditions: O ₂ = 20 sccm, 50 W, 20 Pa, 5 minutes Measurement of film loss: Alphastep 500 manufactured by KLA Tencor

(8) The amount of film reduction of the resist film and the Si substrate was determined by the following calculation formula.
Reduction amount of resist film = film thickness A + film thickness C−film thickness B
Reduction amount of Si substrate film = film thickness C
(9) The etching rate of the resist film and the Si substrate was calculated from the slope of the graph of the etching time and the amount of film loss.
(10) The resist film etching rate was divided by the Si substrate etching rate to standardize.
(11) The etching rate of the resist film to which the standardized fullerene derivative is not added (Comparative Example 2) is divided by the etching rate of the resist film to which the standardized fullerene derivative is added (Examples 6 to 8). The ratio of the obtained speed was calculated as an improvement rate ([%]) and compared.
The above results are shown in Table 8.

As is clear from Table 8, Comparative Example 2 which is OEBR-1000LB with no fullerene derivative added has a 45% etching resistance improvement effect in Example 6 by the addition of the fullerene derivative. In Examples 7 and 8, the effects of improving etching resistance by 49% and 38% were obtained by adding fullerene derivatives, respectively.
The reason why the dry etching resistance is remarkably improved by adding a small amount of fullerene derivative as in the above results is not clear, but according to the inventor's guess, as described in Japanese Patent No. 3515326. In addition to the increase in film density due to the presence of fullerene derivatives, which are aggregates of carbon with high etching resistance, in the film and the inhibition of the penetration of etching species into the film, the radical trapping effect of fullerenes This is due to a synergistic effect due to multiple factors such as suppressing the decomposition of the resist resin, and further because the fullerene derivative of the present invention is highly soluble in organic solvents, and is uniformly highly dispersed in the film. It is guessed. Due to these factors, it is considered that the fullerene derivative of the present invention expresses an effect of improving etching resistance far beyond expectation.

[Evaluation of optical constants]
The resist solution not containing the fullerene derivative prepared in Comparative Example 2 and the resist solution containing the fullerene derivative prepared in Example 6 were each applied onto a silicon substrate, and rotated at a rotational speed of 500 rpm for 10 seconds and then at 4000 rpm for 40 seconds. Rotated for seconds. Then, it heat-dried at 170 degreeC for 60 minutes, and formed the thin film with a film thickness of 100 nm.
Using a spectroscopic ellipsometer UVISEL manufactured by HORIBA Joban Yvon and control analysis software DeltaPsi2, measurement and analysis were performed at a light incident angle of 60 °, a detection angle of 60 °, and a wavelength range of 2600 nm to 190 nm to obtain a refractive index and an extinction coefficient. Of the results, the refractive index and extinction coefficient at 193 nm and 248 nm are shown in Table 9. Moreover, the wavelength spectrum of the refractive index in the wavelength range 1000-191 nm in the resist film of Example 6, and the extinction coefficient is shown in FIG.

From the above results, it can be seen that the addition of the fullerene derivative of the present invention can significantly improve the etching resistance without causing a large change in the optical constant.
The fact that the optical constant does not change greatly means that, when added to a photoresist in a multilayer structure of photolithography, the influence on the design of the anti-reflection film on the upper and lower layers of the photoresist is small, and Even when used as an additive to a photoresist underlayer film, the addition has little effect on the optical constant, so the etching resistance can be improved without impairing the original optical characteristics, etc., which is very useful. .
Further, the fact that the extinction coefficient hardly increases means that there is no decrease in light transmission necessary for photosensitivity, that is, no decrease in resist sensitivity occurs.
The fullerene derivative of the present invention is excellent as an additive for improving etching resistance of a photoresist, an antireflection film, and a coating type mask material (hard mask).

  The fullerene derivative of the present invention can be used in any field. Among them, the fullerene derivative of the present invention has the characteristics that it has high solubility in ester solvents such as PGMEA and can be easily produced at low cost. Can be preferably used for applications such as manufacturing of semiconductor integrated circuits, masks for manufacturing semiconductor integrated circuits, manufacturing of integrated circuits for liquid crystals, resist materials for manufacturing liquid crystal screens, and the like. In addition to KrF excimer lasers and ArF excimer lasers, it can be used as an underlayer film material that functions as a photoresist and antireflection film suitable for shortening the wavelength of light sources such as EUV (extreme ultraviolet light) and EB (electron beam). It can be particularly preferably used for applications of photoresist, nanoimprint, and interlayer insulating film. Among them, it can be particularly preferably used for a photoresist using an ArF excimer laser as a light source and an underlayer film material having a function of an antireflection film by utilizing the optical property of low absorbance at a wavelength of 193 nm.

2 is a chart showing the wavelength spectrum of the refractive index and extinction coefficient of the fullerene derivative film of Example 1. FIG. 2 is a graph showing a TG-DTA measurement result of the fullerene derivative of Example 1. FIG. 3 is a chart showing an absorption spectrum of the fullerene derivative film of Example 1. FIG. 4 is a chart showing the wavelength spectrum of the refractive index and extinction coefficient of the fullerene derivative film of Example 2. 10 is a chart showing the wavelength spectrum of the refractive index and extinction coefficient of the fullerene derivative film of Example 3. 10 is a chart showing the wavelength spectrum of the refractive index and extinction coefficient of the fullerene derivative film of Example 4. 10 is a chart showing the wavelength spectrum of the refractive index and extinction coefficient of the fullerene derivative film of Example 5. It is a chart which shows the wavelength spectrum of the refractive index and extinction coefficient of the resist film of Example 6.

Claims (16)

In the partial structure represented by the following formula (I) of the fullerene skeleton,
C ¹ is bonded to a hydrogen atom or an optional substituent,
A fullerene derivative, wherein C ^{6 to} C ⁸ are each independently bonded to an organic group having a structure represented by the following formula (II).

(In formula (I), C ^{1 to} C ¹⁰ all represent carbon atoms constituting the fullerene skeleton.)

(In the formula (II), Ar represents an aromatic hydrocarbon group having 8 to 18 carbon atoms, and n represents an integer of 1 to 3)   The fullerene derivative according to claim 1, wherein Ar in the formula (II) is a condensed polycyclic hydrocarbon group having 8 to 18 carbon atoms. The fullerene derivative according to claim 1, wherein the C ^{6 to} C ¹⁰ are each independently bonded to an organic group having a structure represented by the formula (II). C ¹ is bonded to a hydrogen atom or an arbitrary substituent, and C ^{6 to} C ⁸ and / or C ^{6 to} C ¹⁰ are each independently an organic group having a structure represented by the formula (II) The fullerene derivative according to any one of claims 1 to 3, wherein the fullerene derivative has a plurality of the partial structures represented by the formula (I) bonded thereto.   The fullerene derivative according to any one of claims 1 to 4, wherein Ar in the formula (II) is a naphthalene skeleton.   6. The fullerene derivative according to any one of claims 1 to 5, wherein n in the formula (II) is 1. The fullerene derivative according to any one of claims 1 to 6, wherein the formula (II) has a structure represented by the following formula (III).

The fullerene derivative according to any one of claims 1 to 7, wherein the C ¹ is bonded to an organic group having 1 to 30 carbon atoms. The fullerene derivative according to claim 8, wherein the C ¹ is bonded to a methyl group. The fullerene derivative according to claim 8, wherein the C ¹ is bonded to an alkenyl group. The fullerene skeleton, characterized in that a fullerene C _60, fullerene derivative according to any one of claims 1 to 10. The fullerene skeleton, characterized in that a fullerene C _70, fullerene derivative according to any one of claims 1 to 10. The fullerene derivative according to any one of the fullerene skeleton, characterized in that it comprises fullerene other than fullerene C ₆₀ and C _70, claims 1 to 10.   A fullerene derivative solution obtained by dissolving the fullerene derivative according to any one of claims 1 to 13 in a solvent.   The fullerene derivative solution according to claim 14, wherein the solvent is an ester solvent.   A fullerene derivative film comprising the fullerene derivative according to any one of claims 1 to 13.

Images