JP2008280323A - Fullerene derivative, solution and film thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrochemically stable fullerene derivative having high solubility in ester solvents such as PGMEA (propylene glycol-1-monomethyl ether-2-acetate) irrespective of a multiple addition fullerene derivative having a monohydric phenol as an addition substituent. <P>SOLUTION: In a partial structure of the fullerene skeleton, represented by formula (I), C<SP>1</SP>is bound to a hydrogen atom or an optional substituent and C<SP>6</SP>to C<SP>8</SP>are each bound to a hydroxyphenyl group substituted with an alkyl group or a halogen group. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

Since the establishment of a large-scale synthesis method for C ₆₀ in 1990, research on fullerene has been vigorously developed. As a result, many fullerene derivatives have been synthesized and their various functions have been clarified. Along with this, various applications 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, it may be referred to as “triple-added partial structure” as appropriate), or a partial structure in which substituents are added to all of C ^{6 to} C ¹⁰ (hereinafter referred to as “5-fold added partial structure” as appropriate). Various fullerene derivatives having) have been synthesized and reported.

上記式（Ｉ）中、Ｃ¹〜Ｃ¹⁰は何れも、フラーレン骨格を構成する炭素原子を表わす。

In the 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 five addition 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”.

Of 5 polyaddition fullerene derivative, for example, 5 polyaddition fullerene derivative C ₆₀ backbone is adapted to π-electron conjugated 50 electron system, different stereoisomeric the C ₆₀ unsubstituted which is π-electron conjugated 60 electron system It has configuration and electronic properties.

In addition, as a triple addition fullerene derivative having a smaller number of substituents than a five addition fullerene derivative, for example, a triple addition C ₇₀ derivative which is a π-electron conjugate of 66 electrons has been synthesized and reported. These triple addition fullerene derivatives have different physical properties from not only unsubstituted C ₆₀ and C ₇₀ but also 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.

Multi-addition fullerene derivatives such as 5-addition C ₆₀ derivatives and 3-addition C ₇₀ derivatives have a unique structure in which organic groups are added intensively to specific sites of fullerene and have a long π-electron conjugation. 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, the fullerene derivative preferably exhibits high solubility in an organic solvent. .
Some polyaddition 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 is generally used in industrial applications. A multi-addition fullerene derivative exhibiting high solubility in an ester solvent represented by the above has also been developed (see Patent Document 1).

JP 2006-56878 A

  However, not only the high solubility in PGMEA, but also the electrochemical stability and the reaction control during further reaction are easy, and the multiple addition fullerene derivative has various characteristics such as the solubility control in alkaline solvent. Is desired.

Moreover, in the conventional technique represented by the above-mentioned Patent Document 1, a phenyl group (phenol group) having one or more hydroxyl groups is used as an additional substituent for the purpose of improving the solubility in various solvents. Having multiple addition fullerene derivatives have been synthesized. However, in the case of a polyaddition fullerene derivative having a phenyl group having only one hydroxyl group (monovalent phenol group) as an addition substituent, the organic group bonded to C ¹ is a hydrogen atom or a methyl group, PGMEA, etc. The solubility in the ester-based organic solvent was not sufficient.

  Furthermore, in the case of a polyaddition fullerene derivative having a phenyl group (polyhydric phenol group) having two or more hydroxyl groups as an additional substituent, when these are used as raw materials and further as an intermediate for obtaining the target product, the number of hydroxyl groups In some cases, the reaction control is difficult due to the large amount. In addition, when the polyaddition fullerene derivative is easily oxidized and forms a quinone structure, or a hydrogen atom sandwiched between hydroxyl groups is susceptible to another substitution reaction, etc. was there.

  The present invention has been made in view of the above-described problems. That is, the present invention provides a fully-added fullerene derivative having a monohydric phenol as an additional substituent, an electrochemically stable fullerene derivative having high solubility in an ester solvent such as PGMEA, and the like. It is an object to provide a solution containing a fullerene derivative and a film containing the fullerene derivative.

  As a result of intensive studies to solve the above problems, the present invention introduces a phenyl group having a specific substituent and simultaneously having one hydroxyl group (substituted phenol group) as an additional substituent. A fullerene derivative having high solubility in an ester solvent, high stability and easy reaction control was developed, and the present invention was completed.

（前記式（Ｉ）中、Ｃ¹〜Ｃ¹⁰は何れも、フラーレン骨格を構成する炭素原子を表わす。）

（前記式（II）中、Ｒは有機基又は第３周期以前のハロゲン原子を表わし、ｍは１〜４の整数を表わす。但し、ｍが２以上の場合、Ｒは同種類であっても良く、異なる種類であっても良い。） 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 It exists in the fullerene derivative characterized by couple | bonding with the organic group of the structure represented by following formula (II) (Claim 1).

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

(In the formula (II), R represents an organic group or a halogen atom before the third period, and m represents an integer of 1 to 4. However, when m is 2 or more, R may be the same type. Well, it can be a different type.)

At this time, it is preferable that the C ^{6 to} C ¹⁰ are independently bonded to an organic group having a structure represented by the formula (II).

  The m is preferably 1 or 2 (claim 3).

  Furthermore, it is preferable that an OH group is bonded to the carbon atom at the 4-position of the phenyl group in the formula (II).

  Moreover, it is preferable that at least one of the R is an alkyl group or a halogen atom before the third period.

  Furthermore, it is preferable that at least one of the R is a methyl group, a chlorine atom, or a fluorine atom (Claim 6).

Further, it is preferable that the fullerene skeleton is a fullerene C ₆₀ (claim 7).

  Another gist of the present invention resides in a fullerene derivative solution, wherein the fullerene derivative of the present invention is dissolved in a solvent (claim 8).

  At this time, it is preferable that the solvent is an ester solvent.

  Still another subject matter of the present invention lies in a film characterized by comprising the fullerene derivative of the present invention (claim 10).

  According to the present invention, a fullerene derivative having high solubility in an ester solvent such as PGMEA, easy reaction control, and electrochemically stable, and a fullerene derivative solution and a film containing the same 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 fullerenes 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.
In the present specification, a fullerene skeleton having i carbon atoms (where i represents an arbitrary natural number) is appropriately represented by the 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 in the fullerene skeleton, and those having a complex formed with another metal atom or compound.

The fullerene skeleton of the fullerene derivative of the present invention is not limited, but among them, C ₆₀ or C ₇₀ is preferable, and C ₆₀ is more preferable. 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 derivative of C ₆₀ or C _70, and more preferably a derivative of C _60.

（前記式（Ｉ）中、Ｃ¹〜Ｃ¹⁰は何れも、フラーレン骨格を構成する炭素原子を表わす。） 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 It is characterized by being bonded to an organic group (that is, a substituted phenol 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 the formula (I), C ^{1 to} C ¹⁰ all represent carbon atoms constituting the fullerene skeleton.)

（前記式（II）中、Ｒは有機基又は第３周期以前のハロゲン原子を表わし、ｍは１〜４の整数を表わす。但し、ｍが２以上の場合、Ｒは同種類であっても良く、異なる種類であっても良い。）

(In the formula (II), R represents an organic group or a halogen atom before the third period, and m represents an integer of 1 to 4. However, when m is 2 or more, R may be the same type. Well, it can be a different type.)

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 arbitrary 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, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, isopropyl, 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; Aralkyl groups such as benzyl group, p-methoxybenzyl group and phenylethyl group; Aryl groups such as phenyl group, biphenyl group, naphthyl group, anthracenyl group and toluyl group Alkoxy groups such as methoxy and ethoxy groups; aryloxy groups such as phenoxy groups; monomethyl Substituted amino groups such as amino group, dimethylamino group, monodiethylamino group and diethylamino group; alkoxycarbonyl groups such as methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, isopropoxycarbonyl group, butoxycarbonyl group and tert-butoxycarbonyl group Aryloxycarbonyl group; 5-membered heterocyclic group such as thienyl group, thiazolyl group, isothiazolyl group, furyl group, oxazolyl group, isoxazolyl group, pyrrolyl group, imidazolyl group, pyrazolyl group; pyridyl group, pyridazyl group, pyrimidyl group, pyrazyl Group, 6-membered heterocyclic group such as piperidyl group, piperazyl group, morpholyl group; thiocarbonyl group such as thioformyl group, thioacetyl group, thiobenzoyl group; trimethylsilyl group, dimethylsilyl group, monomethyl group Group, triethylsilyl group, diethylsilyl group, monoethylsilyl group, triisopropylsilyl group, diisopropylsilyl group, monoisopropylsilyl group, triphenylsilyl group, diphenylsilyl group, monophenylsilyl group, etc. Can be 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 of 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.

Further, 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, preferably 6 or less. When R ¹⁰ has a substituent, the number of carbon atoms 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 hydrogen atom; halogen atom; alkyl group such as methyl group, ethyl group, propyl group; hydroxyalkyl group such as hydroxyethyl group, hydroxypropyl group, hydroxybutyl group; Carboxyl group; alkoxycarbonyl group; and the like.
Among them, R ¹⁰ is more preferably an alkyl group from the viewpoint of ease of synthesis and stability in the air, and a methyl group is particularly preferable from the viewpoint of thermal stability and cost. Furthermore, R ¹⁰ is a hydroxyl group, an alkoxycarbonyl group, or the like in that the solubility of the fullerene derivative of the present invention in alcohols or ester solvents can be further increased, and in that it can be easily substituted with another functional group. An alkyl group containing a polar functional group is preferred.

Subsequently, the organic group having a structure represented by the formula (II) (that is, R ²⁰ ) will be described in detail.
R ²⁰ is a monovalent group in which a hydroxyl group (OH group), an organic group and / or a halogen atom before the third period are bonded to a phenyl group. 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.

In the formula (II), the number of hydroxyl groups (OH groups) bonded to the phenyl group is one. In this case, the position at which the hydroxyl group is bonded to the phenyl group is not limited and is arbitrary, but it is preferably bonded to the 4-position carbon atom of the phenyl group from the viewpoint of raw material procurement. That is, R ²⁰ is preferably a phenol group having a hydroxyl group bonded to the 4-position.

  On the other hand, the group bonded to the phenyl group other than the hydroxyl group in the formula (II) (that is, R in the formula (II)) represents an organic group or a halogen atom before the third period. Examples of R include an organic group such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, isopropyl group, sec-butyl group, linear or branched chain alkyl group such as iso-butyl group, tert-butyl group, tert-amyl group, 2-methylbutyl group, 3-methylbutyl group; cyclopropyl group, cyclopentyl group, cyclobutyl group, cyclohexyl group, etc. Cyclic alkyl groups; alkenyl groups such as allyl groups; aryl groups such as phenyl groups, biphenyl groups, and naphthyl groups; alkoxy groups such as methoxy groups and ethoxy groups; aryloxy groups such as phenoxy groups; Examples of the halogen atom include chlorine and fluorine. Among these, from the viewpoint of raw material procurement, an alkyl group and a halogen atom before the third period are preferable, and a methyl group, chlorine, and fluorine are particularly preferable. When m is 2 or more, R may be the same type or a combination of different types.

In the formula (II), m represents the number of R bonded to the phenyl group, and specifically represents an integer of 1 or more and 4 or less. Among these, 2 or less is preferable from the viewpoint of raw material procurement. That is, m is preferably 1 or 2.
Furthermore, in the formula (II), the position where R is bonded to the phenyl group is arbitrary. When a plurality of Rs are bonded to the phenyl group, the positional relationship of each group is arbitrary, including the position of the hydroxyl group. In the formula (II), a phenyl group is shown, but other aromatic ring groups such as a biphenyl group, a naphthyl group, and an anthracenyl group can be used instead of the phenyl group. In this case, the number of substituents bonded to the aromatic ring group can be appropriately adjusted according to the type of the aromatic ring group. However, a phenyl group is preferable from the viewpoint of raw material procurement.

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 the ester solvent, it is desirable that not only C ^{6 to} C ⁸ but also all of C ^{6 to} C ¹⁰ are independently bonded to R ²⁰ . R ²⁰ may be groups having the same structure or different structures, but from the viewpoint of easy synthesis, all of R ²⁰ are preferably groups having the same structure.

In the present specification, C ^{1 of} formula (I) is bonded to a hydrogen atom or an organic group (that is, R ¹⁰ ), and C ^{6 to} C ⁸ are each independently an organic group having a structure represented by formula (II) ( That is, the partial structure bonded to R ²⁰ ) may be referred to as “the triple addition partial structure of the present invention”. In addition, C ¹ in the formula (I) is bonded to a hydrogen atom or an organic group (that is, R ¹⁰ ), and C ^{6 to} C ¹⁰ are each independently an organic group (that is, R in the structure represented by the formula (II)). 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.
A triple addition fullerene derivative represented by the general formula C _i (R ²⁰ ) ₃ (R ¹⁰ ) having one triple addition partial structure of the present invention on the fullerene skeleton.
A 5-addition fullerene derivative represented by the general formula C _i (R ²⁰ ) ₅ (R ¹⁰ ), having one 5-addition partial structure 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.
-An 8-fold addition 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 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 C _i (R ²⁰ ) ₅ (R ¹⁰ ) having one pentaaddition partial structure of the present invention on the fullerene skeleton. However, it is preferable because it is easy to manufacture.

  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 above ester solvent, that is, having high solubility in the above ester solvent means that the fullerene derivative of the present invention is dissolved in the above-mentioned widely used solvents in the industry. 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. Accordingly, the high solubility of the fullerene derivative of the present invention in an ester solvent means that the fullerene derivative of the present invention is converted into an organic solar cell such as a dye-sensitized solar cell or an organic thin film solar cell; an organic transistor / diode; General organic devices such as light-emitting elements (organic EL elements) and nonlinear optical materials; resin additives; lubricants; insulating films; battery substrates and additives for batteries such as Li secondary batteries, fuel cells and capacitors, surface modification, etc. Coating materials, other materials and additives constituting members such as separators; additives for metals, ceramics, etc .; additives for sliding applications such as solid lubricants and lubricating oil additives; catalysts; paints; inks; 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 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 present inventors, in addition to the acidity of the hydroxyl group of the phenol group of R ²⁰ , substitution on the phenol group It is considered that the introduction of a group reduces the molecular interaction with the neighboring fullerene derivative.

  By the way, when the fullerene derivative of the present invention is formed using the ester solution, the film has a specific absorption spectrum. As described above, in addition to the above-described solubility, the fullerene derivative of the present invention has a specific absorption spectrum in a film state, so that the fullerene derivative of the present invention can be efficiently manufactured as a whole with respect to the light source wavelength and apparatus used in the manufacturing apparatus It becomes possible to design to realize Furthermore, in a liquid immersion apparatus and a washing | cleaning apparatus, the design which prevents a processing effect and liquid mixing and spreading | diffusion becomes possible by having a specific contact angle. These specific absorption spectra can be applied to other optical parts such as optical filters, and the specific contact angle can be applied to a protective film by coating.

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 three 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.

  In addition, the fullerene derivative of the present invention has a relatively small number of hydroxyl groups when a further reaction such as modification of a phenol group is performed, so that the control of the number and position of the modifying groups is relatively easy.

  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 the substituent is bonded by a carbon-carbon bond. The fullerene derivative of the present invention can exist stably without being decomposed even at a temperature at which thermal decomposition starts with a normal organic substance. Therefore, the fullerene derivative of the present invention can 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 performing a heat resistance test at a high temperature or 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 be circulated, the kind of bread, the heating rate, the measurement upper limit temperature, the amount of sample and the like 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 production method of 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. Further, when C ¹ is bonded to a halogen atom, the method described in JP-A No. 2002-241389 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 production method 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 and reacted. The fullerene derivative of the present invention is obtained. 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 to be present in the reaction system, only one kind may be used alone, or two or more kinds may be used in any combination and 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 in combination of two or more 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 that those total amount satisfy | fills 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 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 (R) having a structure represented by formula (II) in C ⁶ -C ⁸ or C ⁶ -C ¹⁰ of the partial structure of formula (I) ²⁰ ) It is desirable to carry out the reaction to add. 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 a 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 32 times mol or less, preferably 16 times mol or less, in the ratio to the raw material fullerene. Is desirable. If the amount of the 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 introducing 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 introducing agent is not 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 deaeration 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, the R ¹⁰ introducing agent is not limited as long as the halogen atom can be introduced into the fullerene skeleton. Examples of the R ¹⁰ introduction agent include halogenating agents such as chlorine, bromine, iodine, N-bromosuccinimide, N-chlorosuccinimide, and N-iodosuccinimide. 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 introduction 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 these, regarding the R ¹⁰ introduction agent, it is preferable to use methyl iodide alone from the viewpoints of easiness of reaction, stability of the product and cost reduction.

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 in progress. 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 production method 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 can dissolve and / or disperse the above-mentioned fullerene, transition metal, Grignard reagent and R ¹⁰ introduction agent suitably.

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 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.

[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, degassing such as nitrogen bubbling or vacuum degassing. It is preferable to add to the reaction system after the 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 having a protecting group 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 at least mol, more preferably at least 1.4 mol, and usually at most 10 mol, preferably at most 5 mol, more preferably at most 3 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, 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 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-mentioned solvents, in particular organic solvents such as ester solvents, ketone solvents, and ether solvents, the fullerene derivative solution is applied and dried to form a film containing the fullerene derivative ( Hereinafter, a “fullerene derivative film” can be produced as appropriate. In addition to the fullerene derivative and the solvent, the fullerene derivative solution used at this time may contain other arbitrary compounds as long as the excellent physical properties of the fullerene derivative of the present invention are not significantly impaired.

The coating method is arbitrary, but for example, a spray method, a spin coating method, a dip coating method, a roll coating method, or the like can be used.
Moreover, although there is no restriction | limiting in the object to apply | coat, Usually, it applies to a board | substrate. The substrate is not limited, and examples thereof include organic coatings, silicon substrates, polysilicon films, silicon oxide films, silicon nitride films such as silicon nitride films, and inorganic coatings such as metal wiring.

  Although there is no restriction | limiting in the drying method of the formed coating film, Usually, heat drying is performed. Although the content of the specific heat-drying process is arbitrary unless the effect of this invention is impaired remarkably, normally, it is preferable to heat at 80-300 degreeC in the range for 10 second to 300 second. 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. Moreover, it is preferable to perform heating in air | atmosphere or inert gas atmosphere, such as argon and nitrogen.

  The film thickness in the fullerene derivative film of the present invention varies greatly depending on applications 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 Is 300 nm or less.

  The fullerene derivative film of the present invention is usually a uniform film. In addition, the fullerene derivative film of the present invention can measure the refractive index (n value) and extinction coefficient (k value) 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 are greatly different in numerical values required depending on the use of the fullerene derivative film. Further, the required optical values of the above-mentioned optical characteristics vary greatly 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 high etching resistance because the fullerene derivative as a component retains a large amount of π-electron conjugation of the fullerene skeleton and a phenyl ring is introduced as a substituent. Since it can be expected, it is suitably used for photoresist applications.

[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 of the present invention 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. In addition, since 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 exhibits an excellent function as a single layer of a multilayer film. It is expected.

[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 step of sequentially removing the transfer layer; a step of contacting the transfer layer made of a curable monomer 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 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]
Application to organic solar cells is also possible. In this field, although there are many advantages as compared with silicon-based inorganic solar cells, the energy conversion efficiency is low and the practical level has not been sufficiently reached. 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, the fullerene derivative of the present invention can control the layer separation from the electron donor layer containing a conductive polymer, etc., and the morphology control such as the alignment orientation and fine packing property of the derivative molecule. This makes it possible to improve the characteristics and provide high flexibility in device design. In addition, when the fullerene derivative of the present invention is used, it is possible to easily realize a large area at low cost by a normal printing method, 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. In general, 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, THP represents a tetrahydropyranyl group, THF represents tetrahydrofuran, ODCB represents orthodichlorobenzene, and DMSO represents dimethyl sulfoxide. Further, Me represents a methyl group, tBu represents a t-butyl group, and Ph represents a phenyl group.

[Example 1: Production of C ₆₀ (3-F-4-OH-C ₆ H ₃ ) ₅ (-CH ₃ )]
After cooling a THF suspension (112 mL) of a copper (I) bromide dimethyl sulfide complex (12.96 g, 63.0 mmol) to 5 ° C., a 3-F-4-OMe-C ₆ H ₃ 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 9 hours. MeI (3 mL, 48 mmol) was added and stirred for another 6 hours. The reaction solution was filtered to remove THF, diluted with toluene, and subjected to silica column chromatography (developing solution: toluene). The solution was concentrated, crystallized with methanol (700 mL) and hexane (300 mL), and vacuum-dried at 50 ° C. to obtain C ₆₀ (3-F-4-OMe-C ₆ H ₃ ) ₅ (—CH ₃ ) was obtained as the product of an orange solid (6.60 g, 4.85 mmol, yield 87.3%).

Next, an orthodichlorobenzene solution (126 mL) of C ₆₀ (3-F-4-OMe—C ₆ H ₃ ) ₅ (—CH ₃ ) (3.00 g, 2.21 mmol) was prepared and cooled to 5 ° C. After that, a BBr ₃ -methylene chloride solution (1.0 mol / L, 16.8 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 (40 mL), ethyl acetate (100 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 3 hours to give the title compound C ₆₀ (3-F-4-OH—C ₆ H ₃ ) ₅ (—CH ₃ ). Obtained as the product of an orange solid (2.13 g, 1.65 mmol, 74.8% yield).

The obtained product was measured by ¹ H-NMR and HPLC. ¹ H-NMR was measured at 400 MHz using DMSO-d6 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 = 3/7
Detector: UV290nm

  As a result of HPLC measurement, it was observed at 97.5 (Area%) at a retention time of 2.86 min.

Moreover, the measurement result of < ¹ > H-NMR was as follows.
[ ¹ H-NMR (DMSO-d6, 400 MHz)]
10.15 ppm (brs, OH, 4H), 10.03 ppm (s, OH, 1H), 7.45 ppm (m, Ph, 5H), 7.02 ppm (m, Ph, 6H), 6.75 ppm (m, Ph, 4H), 1.48 ppm (s, C ₆₀ Me, 3H)

From the above results, it was confirmed that the obtained product was the title compound C ₆₀ (3-F-4-OH—C ₆ H ₃ ) 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.

[Example 2: Production of C ₆₀ (3-Me-4-OH-C ₆ H ₃ ) 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-Me-4-OMe-C ₆ H ₃ 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 5 hours. Thereto was added MeI (5 mL, 80 mmol), and the mixture was further stirred for 12 hours. The reaction solution was filtered to remove THF, diluted with toluene, and subjected to silica column chromatography (developing solution: toluene). The solution was concentrated, crystallized with methanol (800 mL), and vacuum-dried at 50 ° C., whereby C ₆₀ (3-Me-4-OMe-C ₆ H ₃ ) ₅ (—CH ₃ ) was orange. Obtained as the product of solid (6.55 g, 4.89 mmol, yield 88.0%).

Next, an orthodichlorobenzene solution (42 mL) of C ₆₀ (3-Me-4-OMe-C ₆ H ₃ ) ₅ (—CH ₃ ) (1.0 g, 0.75 mmol) was prepared and cooled to 5 ° C. After that, BBr ₃ -methylene chloride solution (1.0 mol / L, 5.6 mL) was added, and the temperature was raised to 25 ° C. After stirring at room temperature for 12 hours, the reaction was stopped with ion-exchanged water (15 mL), ethyl acetate (30 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 3 hours to give the title compound C ₆₀ (3-Me-4-OH—C ₆ H ₃ ) ₅ (—CH ₃ ). Obtained as the product of an orange solid (0.81 g, 0.64 mmol, 85.3% yield).

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 97.0 (Area%) at 2.47 min.

Moreover, the measurement result of < ¹ > H-NMR was as follows.
[ ¹ H-NMR (DMSO-d6, 400 MHz)]
9.50 ppm (brs, OH, 3H), 9.45 ppm (s, OH, 1H), 9.37 ppm (s, OH, 1H), 7.51 to 7.37 ppm (m, Ph, 8H), 6. 96 to 6.74 ppm (m, Ph, 6H), 6.54 ppm (d, Ph, 1H), 2.05 ppm (brs, PhMe, 12H), 1.99 ppm (s, PhMe, 3H), 1.83 ppm ( s, C ₆₀ Me, 3H)

From the above results, it obtained product is the title compound _{C 60 (3-Me-4} -OH-C 6 H 3) 5 (-CH 3) was confirmed.
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 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 Table 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. The measurement was performed under the following conditions.

Sample mass: 5.040 mg
Gas flow rate: Nitrogen gas, 200 mL / min
Bread: Pt
Temperature increase rate: 10 ° C / min
Measurement temperature: 30-900 ° C

Further, a propylene glycol monomethyl ether (PGME) solution of the obtained fullerene derivative was prepared (5 wt%), 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 quartz substrate (disk shape) of 30 mmφ (thickness 2 mm) (the number of rotations was initially 10 seconds at 500 rpm, and then 40 seconds at 3000 rpm). Then, the solvent was removed and dried at 40 ° C. for 2 hours in 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 changed to a double-beam type in a region of 190 nm to 1500 nm with a visible / ultraviolet spectrophotometer (manufactured by Shimadzu Corporation, UV-17010), and the light source was switched between a halogen lamp and a deuterium lamp. The method and 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.

  Further, a PGME solution of the obtained fullerene derivative was prepared (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 seconds at 500 rpm, and subsequently 40 seconds at 1500 rpm). 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 in the same manner. The results are shown in Table 4. The measurement was repeated 2 times under the condition 1 minute after dropping, and the average value was evaluated.

[Example 3: Production of C ₆₀ (2-Me-4-OH-C ₆ H ₃ ) 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 2-Me-4-OMe-C ₆ H ₃ 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 8 hours. Thereto was added MeI (5 mL, 80 mmol) and the mixture was further stirred for 12 hours. The reaction solution was filtered to remove THF, diluted with toluene, and subjected to silica column chromatography (developing solution: toluene). The solvent was concentrated, crystallized with methanol (800 mL), and vacuum-dried at 50 ° C., whereby C ₆₀ (2-Me-4-OMe-C ₆ H ₃ ) ₅ (—CH ₃ ) was orange. Obtained as the product of a solid (6.24 g, 4.66 mmol, 83.8% yield).

Next, an orthodichlorobenzene solution (84 mL) of C ₆₀ (2-Me-4-OMe-C ₆ H ₃ ) ₅ (—CH ₃ ) (2.15 g, 1.60 mmol) was prepared and cooled to 5 ° C. After that, BBr ₃ -methylene chloride solution (1.0 mol / L, 10.8 mL) was added, and the temperature was raised to 25 ° C. After stirring at room temperature for 12 hours, the reaction was stopped with ion-exchanged water (50 mL), ethyl acetate (100 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 (500 mL), and vacuum-dried at 50 ° C. for 3 hours to give the title compound C ₆₀ (2-Me-4-OH—C ₆ H ₃ ) ₅ (—CH ₃ ). Obtained as the product of an orange solid (1.64 g, 1.29 mmol, 80.7% yield).

In the same manner as in Example 1, the obtained product was subjected to HPLC and ¹ H-NMR (400 MHz).
Measured with

    As a result of HPLC measurement, it was observed at 92.0 (Area%) at a retention time of 2.55 min.

[ ¹ H-NMR (DMSO-d6, 400 MHz)]
9.51 ppm (s, OH, 2H), 9.46 ppm (s, OH, 1H), 9.44 ppm (s, OH, 1H) 9.34 ppm (s, OH, 1H), 8.20 ppm (d, Ph , 2H), 7.87 ppm (d, Ph, 1H), 7.80 ppm (d, Ph, 1H), 6.93 ppm (d, Ph, 4H), 6.72 ppm (d, Ph, 1H), 6. 61 ppm (d, Ph, 1H), 6.45 ppm (m, Ph, 4H), 6.20 ppm (d, Ph, 1H), 2.62 ppm (s, PhMe, 3H), 2.49 ppm (s, PhMe, 3H), 2.44ppm (s, PhMe , 3H), 2.42ppm (s, PhMe, 3H), 2.00ppm (s, PhMe, 3H), 1.90ppm (s, C 60 Me, 3H)

From the above results, it was confirmed that the obtained product was the title compound C ₆₀ (2-Me-4-OH-C ₆ H ₃ ) 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.

[Example 4: Production of C ₆₀ (3,5-Me ₂ -4-OH-C ₆ H ₂ ) 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., 3,5-Me ₂ -4-OTHP-C ₆ H ₂ 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 10 hours. Thereto was added MeI (5 mL, 80 mmol), and the mixture was further stirred for 6 hours. The reaction solution was filtered to remove THF, diluted with toluene, and subjected to alumina column chromatography (developing solution: toluene). The solvent was concentrated, crystallized with MeOH (600 mL) and hexane (300 mL), and vacuum dried at 50 ° C. to obtain C ₆₀ (3,5-Me ₂ -4-OTHP-C ₆ H ₂ ) _5. (—CH ₃ ) was obtained as the product of an orange solid (7.89 g, 4.48 mmol, 80.6% yield).

_{Next, C 60 (3,5-Me 2} -4-OTHP-C 6 H 2) 5 (-CH 3) (3.00g, 1.70mmol) in methylene chloride (37.5 mL), methanol (37. 5 mL) mixed solution was prepared, methanesulfonic acid (16.5 μL) was added, and the mixture was stirred at room temperature for 8 hours. The reaction solution was diluted with methylene chloride (30 mL), and then crystallized with hexane (200 mL). The title compound C ₆₀ (3,5-Me ₂ -4-OH—C ₆ H ₂ ) ₅ (—CH ₃ ) was then converted into an orange solid (1.91 g, 1 .42 mmol, yield 83.5%) as product.

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 93.5 (Area%) at a retention time of 2.75 min.

Moreover, the measurement result of < ¹ > H-NMR was as follows.
[ ¹ H-NMR (DMSO-d6, 400 MHz)]
8.42 ppm (s, OH, 2H), 8.37 ppm (s, OH, 2H), 8.29 ppm (s, OH, 1H), 7.33 ppm (s, Ph, 4H), 7.31 ppm (s, Ph, 4H), 6.88 ppm (s, Ph, 2H), 2.11 ppm (s, PhMe, 12H), 2.06 ppm (s, PhMe, 12H), 1.92 ppm (s, PhMe, 6H), 1 .35 ppm (s, C ₆₀ Me, 3H)

From the above results, it obtained product is the title compound _{C 60 (3,5-Me 2 -4} -OH-C 6 H 2) 5 (-CH 3) was confirmed.
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.

[Comparative Example 1: Production of C ₆₀ (4-OH-C ₆ H ₄ ) ₅ (CH ₃ )]
C ₆₀ (4-OTHP-C ₆ H ₄ ) ₅ (H) was synthesized by the method described in Supplementary Information of Nature, 419, 702-705, 2002. A methyl group was introduced into this hydride by the method described in Japanese Patent Application Laid-Open No. 2005-15470 (Example 8) (tBuOK was allowed to act on a THF solution, and then MeI was added). The title compound was synthesized by deprotection by the method described in the above literature.

The obtained product was subjected to HPLC and ¹ H- in the same manner as in Example 1 except that the solvent of the HPLC measurement sample was changed to THF and the eluent was changed to toluene / methanol = 2/8 (V / V). Measured by NMR.

  As a result of HPLC measurement, a retention time of 4.11 min was observed at 99.00 (Area%).

Furthermore, the measurement result of ¹ H-NMR was as follows.
[ ¹ H-NMR (DMSO-d6, 270 MHz)]
9.60 ppm (s, OH, 4H), 9.48 ppm (s, OH, 1H), 7.58 ppm (m, Ph, 8H), 6.96 ppm (d, Ph, 2H), 6.77 ppm (m, Ph, 8H), 6.49 ppm (d, Ph, 2H), 1.47 ppm (s, Me, 3H)

From the above results, it was confirmed that the obtained product was the title compound C ₆₀ (4-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.

  In Table 1 below, the expression “<1” indicates that the solubility is less than 1 mg / mL, and the expression “> 10” indicates that the solubility is greater than 10 mg / mL.

In addition, the fullerene derivative of this invention shows high solubility also to solvents other than PGMEA. As an example, the solubility in ethyl lactate and methyl ethyl ketone is shown in Table 2.

Table 3 shows the optical constants of the fullerene derivative film produced in Example 2. The compound of Comparative Example 1 was not soluble enough to form a film.

  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. Among them, in addition to KrF excimer laser and ArF excimer laser, a photoresist suitable for shortening the wavelength of a light source such as EUV (extreme ultraviolet light) and EB, and a photoresist as a lower layer material having an antireflection film function, It can be particularly preferably used for applications of nanoimprints and interlayer insulating films.

It is a figure which shows the wavelength spectrum of the refractive index and extinction coefficient of the fullerene derivative film | membrane of Example 2 of this invention. It is a figure which shows the result of TG-DTA of the fullerene derivative of Example 2 of this invention. It is a figure which shows the wavelength spectrum of the light absorbency of the fullerene derivative film | membrane of Example 2 of this invention.

Claims (10)

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

(In the formula (II), R represents an organic group or a halogen atom before the third period, and m represents an integer of 1 to 4. However, when m is 2 or more, R may be the same type. Well, it can be a different type.) 2. The fullerene derivative according to claim 1, wherein C ^{6 to} C ¹⁰ are each independently bonded to an organic group having a structure represented by the formula (II). The fullerene derivative according to claim 1 or 2, wherein m is 1 or 2. The fullerene derivative according to any one of claims 1 to 3, wherein an OH group is bonded to a carbon atom at the 4-position of the phenyl group in the formula (II). 5. The fullerene derivative according to claim 1, wherein at least one of R is an alkyl group or a halogen atom before the third period. 6. 6. The fullerene derivative according to claim 5, wherein at least one of R is a methyl group, a chlorine atom or a fluorine atom. Characterized in that the fullerene skeleton is a fullerene C _60, fullerene derivative according to any one of claims 1 to 6. A fullerene derivative solution, wherein the fullerene derivative according to any one of claims 1 to 7 is dissolved in a solvent. The fullerene derivative solution according to claim 8, wherein the solvent is an ester solvent. A film comprising the fullerene derivative according to any one of claims 1 to 7.

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