JP5350718B2 - Aminated fullerene - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an industrially readily synthesizable aminated fullerene, having high solubility in alcohols with little added groups without deteriorating characteristics of fullerene, and suitably used for various applications such as physiologically active substances, electronic conductive materials, or resin additives. <P>SOLUTION: The industrially readily synthesizable aminated fullerene having high solubility in alcohols with little added groups without deteriorating the characteristics of the fullerene, and suitably used for the various applications such as the physiologically active substances, the electronic conductive materials, or the resin additives is provided by binding an ester group containing a carbon chain having one or more branches through an alkylene chain to one nitrogen atom composing a cyclic amino group containing two nitrogen atoms, and directly binding the other nitrogen atom composing the cyclic amino group to the fullerene. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a fullerene derivative. Specifically, the present invention relates to an aminated fullerene having a specific structure.

Since the development of mass production method of fullerene C ₆₀ in 1990, developed a number of fullerene derivatives, the various functions have been revealed. Along with this, development of various applications such as electron conductive materials, semiconductors, and physiologically active substances using fullerene derivatives has been promoted.

  The physical properties required for fullerene derivatives vary greatly depending on the application field, but in particular, there is a strong demand for dissolving fullerene derivatives in various solvents for the purpose of thin film formation by coating, uniform dispersion in resin, etc. In addition, fullerene derivatives having high solubility in various solvents have been vigorously developed.

  In particular, in the use of an electron conductive material, a fullerene derivative solution is applied by a technique such as spin coating and used as a thin film containing a fullerene derivative, and a fullerene derivative exhibiting high solubility in a solvent is required. For example, Patent Document 1 describes that a fullerene derivative having a specific structure exhibits high solubility in an ester solvent. Specifically, by adding an organic group having a bulky ester substituent to fullerene, high solubility of the fullerene derivative in an ester solvent is achieved.

  In addition, fullerene usually has a property of removing active oxygen, and therefore is expected to be applied to use of a physiologically active substance. Also in this application, since fullerene derivatives are usually used after being dissolved in a solvent, high solubility in polar solvents such as water and alcohol is required, but known to be soluble in water, alcohol, etc. with low toxicity at a high concentration There are not many fullerene derivatives.

  As an example of a fullerene derivative having water solubility, Non-Patent Document 1 describes a hydroxylated fullerene having a maximum of 40 hydroxyl groups added thereto. This fullerene derivative exhibits a high solubility of 58.9 g / L at the maximum in water, and further, although its structure is unknown, a fullerene derivative having a high water solubility of 200 g / L or more is also described. .

  Patent Document 2 reports an aminated fullerene in which an amino group is added to fullerene. This document discloses a technique capable of producing tetraaminofullerene epoxide, which is an aminated fullerene, with high yield and high selectivity by an industrially possible one-step reaction.

  Furthermore, methanol is sometimes used as a poor solvent for crystallization during the production of aminated fullerenes by utilizing the fact that known aminated fullerenes are not soluble in methanol.

JP 2006-56878 A JP 2006-199674 A Summary of the 30th Memorial Fullerene / Nanotube General Symposium p. 149

  Although the fullerene derivative described in Patent Document 1 exhibits high solubility in an ester solvent, in order to industrially produce the fullerene derivative, it is an unstable product prepared from Grignard reagent and a copper compound in the production process. Many for industrial production, such as using organic copper reagents and multi-step processes such as addition, deprotection, and esterification processes, resulting in high production costs and long production times. There was a problem.

  Further, like fullerene hydroxide described in Non-Patent Document 1, fullerene derivatives that have achieved high solubility by adding many additional groups to fullerene have narrow fullerene conjugation. It may be damaged. Furthermore, the fullerene hydroxide has many problems such as the amount of the additional group being different for each hydroxylated fullerene molecule and the identification of the structure thereof being difficult.

  Furthermore, when the present inventors synthesized aminated fullerenes described in Patent Document 2 and confirmed the solubility of these aminated fullerenes in methanol, none of them showed solubility in methanol (specifically, Is 0.1 mg or less of aminated fullerene soluble in 1 mL of methanol). Therefore, the known aminated fullerene has a problem that it is not soluble in alcohol such as methanol.

  The present invention has been made in view of the above problems, and can be easily synthesized industrially, has high solubility in alcohol, has a small number of additional groups, does not impair the properties of fullerene, and has physiological activity. An object of the present invention is to provide an aminated fullerene that can be suitably used for various uses such as substances, electron conductive materials, and resin additives.

  As a result of intensive studies to solve the above problems, the present inventors have obtained an ester group containing a carbon chain having one or more branches and one nitrogen atom constituting a cyclic amino group containing two nitrogen atoms. Bonded via an alkylene chain, the other nitrogen atom constituting the cyclic amino group is directly bonded to fullerene, so that it can be easily synthesized industrially and has high solubility in alcohol. The present inventors have found that an aminated fullerene can be provided that is suitable for various uses such as physiologically active substances, electron conductive materials, resin additives, etc., with a small number of groups and without impairing the properties of fullerene. It was.

（式（１）中、ｍ及びｎは、それぞれ独立に、１以上４以下の整数を表す。また、Ｅは、置換基を有していても良い、１つ以上の分岐を有する、炭素数４以上１０以下のアルキル基を含むエステル基を表す。Ｒ ₄ 、Ｒ ₅ は、それぞれ独立に、水素原子、アルキル基、アルケニル基、アリール基、アラルキル基、ハロゲン原子、ヒドロキシ基、アルコキシ基、またはアルコキシチオ基を表わす。Ｒ ₆ 、Ｒ ₇ は、それぞれ独立に、水素原子、アルキル基、アルケニル基、アリール基、アラルキル基、ハロゲン原子、ヒドロキシ基、アルコキシ基、またはアルコキシチオ基を表わす。） That is, the gist of the present invention is as follows.
Ring-shaped secondary amino group of structures represented by the following formula (1), characterized in that directly bonded to the fullerene consists in aminated fullerene (claim 1).

(In the formula (1), m and n each independently represent an integer of 1 or more and 4 or less. E is an optionally substituted carbon atom having one or more branches. the. R _4, R ₅ representing an ester group containing 4 to 10 alkyl groups, each independently, a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an aralkyl group, a halogen atom, hydroxy group, alkoxy group or, R ₆ and R ₇ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an aralkyl group, a halogen atom, a hydroxy group, an alkoxy group, or an alkoxythio group.

（式（２）〜（４）中、Ｒ¹は、それぞれ独立に、置換基を有していても良い、１つ以上の分岐を有する、炭素数４以上１０以下のアルキル基を表す。） In this case, the ester group is preferably an ester group having one or more structures selected from the group consisting of the following formulas (2), (3) and (4).

(In formulas (2) to (4), each R ¹ independently represents an alkyl group having 4 or more and 10 or less carbon atoms, which may have a substituent and has one or more branches .)

The R ¹ is preferably a t-butyl group and / or a neopentyl group (Claim 3).

  Moreover, in said Formula (1), it is preferable that n is 2. (Claim 4).

  In the formula (1), m is preferably 1 (claim 5).

In addition, R ₆ and R ₇ are each independently a hydrogen atom, or an alkyl group, an alkenyl group, an aryl group, an aralkyl group, a halogen atom, a hydroxy group, an alkoxy group, of 15 g / mol to 200 g / mol, Or it is preferable that it is an alkoxythio group (Claim 6).
Further, the fullerene is C ₆₀ having 60 carbon atoms , and a tetravalent amino group having a structure represented by the above formula (1) and four divalent oxygen atoms are bonded to the fullerene. Amino C ₆₀ -monoepoxide is preferred (Claim 7 ).

（式（５）中、ＮＲ²は、それぞれ独立して、上記式（１）で表される構造の環状２級アミノ基を表す。また、式（５）中、細線で表される炭素−炭素結合は、フラーレンを形成する炭素骨格が有する炭素−炭素結合を表す。） The tetraamino C ₆₀ -monoepoxide preferably has a partial structure represented by the following formula (5) on the fullerene (claim 8 ).

(Carbon in the formula (5), NR ² each independently represent a ring-shaped secondary amino groups of the structure represented by the above formula (1). Further, in the formula (5), represented by the thin line -A carbon bond represents the carbon-carbon bond which the carbon skeleton which forms fullerene has.)

  According to the present invention, it can be easily synthesized industrially, has high solubility in alcohol, has a small number of additional groups, does not impair the characteristics of fullerene, and is a physiologically active substance, an electron conductive material, a resin additive, etc. It is possible to provide an aminated fullerene that is suitably used for various applications.

  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.

  In the present specification, unless otherwise specified, there is no particular limitation on the type of isomers that the organic compound has, for example, optical isomers, positional isomers, geometric isomers and the like. For example, xylene includes ortho-xylene, meta-xylene, para-xylene, and the like, but when it is simply described as “xylene”, xylene may be any of these isomers. Moreover, the organic compound to be used may contain 2 or more types of isomers by arbitrary ratios and combinations.

[1. Aminated fullerene]
In the aminated fullerene of the present invention, a substituted or unsubstituted cyclic secondary amino group having a structure represented by the following formula (1) is directly bonded to the fullerene.

（式（１）中、ｍ及びｎは、それぞれ独立に、１以上４以下の整数を表す。また、Ｅは、１つ以上の分岐を有する炭素鎖を含むエステル基を表す。）

(In formula (1), m and n each independently represent an integer of 1 or more and 4 or less. E represents an ester group containing a carbon chain having one or more branches.)

(Fullerene)
“Fullerene” is a carbon cluster having a closed shell structure formed by arranging carbon atoms in a spherical or rugby ball shape. The carbon number of fullerene is usually 60 or more and usually 120 or less.

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 following description, fullerene having carbon number i (i represents an arbitrary natural number) is appropriately represented by the formula “C _i ”.

Specific examples of the fullerene of the aminated fullerene of the present invention include the above-mentioned specific examples. Among them, C ₆₀ is preferable from the viewpoint of easy availability as a raw material. In addition, fullerene may be used individually by 1 type and may be used 2 or more types by arbitrary ratios and combinations.

(Cyclic secondary amino group)
The cyclic secondary amino group is represented by the above formula (1), and is a cyclic amino group composed of two nitrogen atoms and (n + 2) carbon atoms (hereinafter referred to as “cyclic secondary amino skeleton” as appropriate). The ester group containing a carbon chain having one or more branches is bonded to one nitrogen atom via a carbon chain having m carbon atoms.

(Cyclic secondary amino skeleton)
In said formula (1), n represents carbon number of a carbon chain. The preferable range of n is usually 1 or more, and the upper limit is usually 4 or less, preferably 3 or less, more preferably 2 or less. Among these, n is particularly preferably 2. When there are too many carbon numbers, polarity may become low and the solubility to alcohol may become low.

  Specific examples of the cyclic secondary amino skeleton include N-imidazolidino group, N-piperazino group, N-homopiperazino group and the like. Among these, N-piperazino group and N-homopiperazino group are preferable, and N-piperazino group is more preferable from the viewpoint of easy availability of raw materials for generating a cyclic secondary amino skeleton. In addition, a cyclic | annular secondary amino skeleton may be used individually by 1 type, and may be used for 2 types by arbitrary ratios and combinations.

  In the cyclic secondary amino skeleton, a hydrogen atom of the cyclic secondary amino skeleton may be substituted with a substituent unless the effects of the present invention are significantly impaired. Examples of the substituent that may be included include an alkyl group, an alkenyl group, an aryl group, an aralkyl group, a halogen atom, a hydroxy group, an alkoxy group, and an alkoxythio group. As for the substituents, one type may be substituted alone, or two or more types may be substituted in any ratio and combination.

  The molecular weight of the substituent is arbitrary as long as the effects of the present invention are not significantly impaired, but is usually 9 g / mol or more, preferably 15 g / mol or more, and the upper limit is usually 200 g / mol or less, preferably 150 g. / Mol or less, more preferably 100 g / mol or less. When the molecular weight is too large, the ratio of fullerene per unit weight relatively decreases, and as a result, the fullerene characteristics may not be sufficiently developed.

  Furthermore, the substituent may have a ring as long as the effects of the present invention are not significantly impaired.

  The substituent may have not only a saturated bond but also an unsaturated bond as long as the effects of the present invention are not significantly impaired. The unsaturated bond may be a double bond or a triple bond. Moreover, you may have a double bond and a triple bond by arbitrary ratios and combinations.

(Ester group containing a carbon chain having one or more branches)
In the above formula (1), E represents an ester group containing a carbon chain having one or more branches (hereinafter referred to as “branch-containing ester group” as appropriate), and cyclic 2 via a carbon chain of carbon number m. Bonded to a secondary amino skeleton. The structure of the branch-containing ester group is arbitrary as long as the effects of the present invention are not significantly impaired, but usually, an ester group and a group having any carbon chain having one or more branches (hereinafter referred to as “R” ¹ ”).) Accordingly, the branched ester group is preferably an ester group having one or more structures selected from the group consisting of the following formulas (2), (3) and (4). Among these, an ester group having a structure represented by the following formula (3) is particularly preferable. In addition, a branch containing ester group may be used individually by 1 type, and may be used 2 or more types by arbitrary ratios and combinations.

The number of carbon atoms R ¹ has independently the above formula (2) to (4) is usually 4 or more, and the upper limit thereof is generally 10 or less, preferably 8 or less, more preferably 6 or less . When the number of carbon atoms is too large, the molecular weight of the cyclic secondary amino group with respect to fullerene increases, and as a result, the properties of fullerene may become insufficient.

R ¹ has one or more branches. The number of branches of R ¹ is arbitrary as long as the effects of the present invention are not significantly impaired in the above formulas (2) to (4). Further, the branch in the present invention may be a branch derived from a tertiary carbon atom or a branch derived from a quaternary carbon atom. Among them, those derived from a quaternary carbon atom are preferable. .

Furthermore, the position of branching in R ¹ is arbitrary as long as the effect of the present invention is not significantly impaired, but it is preferably as close to the end of the carbon chain as possible. Specifically, the longest carbon chain in R ¹ is the main chain and counted from the terminal side (that is, when the terminal carbon atom is in the 1st position), in the above formulas (2) to (4), respectively. Independently, it is usually preferable to be at the terminal side, preferably at the 2nd position from the 3rd position. When the branch position is present on the ester group side from the above range, the aminated fullerene may not have sufficient solubility in alcohol. In addition, the position of a branch may be only one place and may be two or more places.

R ¹ may have not only a saturated bond but also an unsaturated bond as long as the effects of the present invention are not significantly impaired. The unsaturated bond may be a double bond or a triple bond. Moreover, you may have a double bond and a triple bond by arbitrary ratios and combinations.

Further, the molecular weight of R ¹ is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 43 g / mol or more, preferably 57 g / mol or more, more preferably 71 g / mol or more, and the upper limit thereof is Usually, it is 500 g / mol or less, preferably 300 g / mol or less, more preferably 150 g / mol or less. If the molecular weight is too small, there is a possibility that a branched structure cannot be formed. If the molecular weight is too large, the number of carbons constituting R ¹ will increase, resulting in a relative decrease in the proportion of fullerene per unit weight. There is a possibility that the characteristics of fullerene are not sufficiently developed.

R ¹ may be a chain or a ring, but is preferably a chain.

R ¹ is preferably a hydrocarbon group. Furthermore, among the hydrocarbon groups, an aliphatic hydrocarbon group and an aromatic hydrocarbon group can be mentioned. As a result of the interaction between the aromatic hydrocarbon group and fullerene, the aminated fullerene of the present invention has sufficient solubility. Among them, an aliphatic hydrocarbon group is more preferable because it may not be expressed. Furthermore, among the aliphatic hydrocarbon groups, for example, an alkyl group, an alkenyl group, an alkynyl group and the like can be mentioned, and among them, an alkyl group is particularly preferable.

From the above viewpoint, in formulas (2) to (4), R ¹ is preferably independently an alkyl group having 4 to 10 carbon atoms. At this time, R ¹ has one or more branches independently in Formulas (2) to (4).

Specific examples of R ¹ include t-butyl group, neopentyl group, 2- (t-butyl) ethyl group, 3- (t-butyl) propyl group, 4,4-dimethylcyclohexyl group, 1-methyl-1- Examples include a cyclohexyl group and a 2,2,3- (trimethyl) -1-n-propyl group. Among these, R ¹ is preferably a t-butyl group or a neopentyl group.

R ¹ may have a substituent unless the effects of the present invention are significantly impaired. Examples of the substituent include an alkyl group, an alkenyl group, an aryl group, an aralkyl group, a halogen atom, a hydroxy group, an alkoxy group, and an alkoxythio group. As for the substituents, one type may be substituted alone, or two or more types may be substituted in any ratio and combination.

The molecular weight of the substituent is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 9 g / mol or more, preferably 15 g / mol or more, more preferably 29 g / mol or more, and its upper limit. Is usually 80 g / mol or less, preferably 60 g / mol or less, more preferably 50 g / mol or less. If the molecular weight is too small, the effect may not be sufficient. If the molecular weight is too large, the molecular weight of R ¹ will increase, resulting in a relative decrease in the proportion of fullerene per unit weight. There is a possibility that the characteristics of fullerene are not sufficiently developed.

  Furthermore, the substituent may have a ring as long as the effects of the present invention are not significantly impaired.

  The substituent may have not only a saturated bond but also an unsaturated bond as long as the effects of the present invention are not significantly impaired. The unsaturated bond may be a double bond or a triple bond. Moreover, you may have a double bond and a triple bond by arbitrary ratios and combinations.

In addition, these substituents may be further substituted in multiple by one or more substituents. As a substituent which can be substituted, the substituent etc. which can be substituted by said R < ¹ > are mentioned, for example.

(Carbon chain of carbon number m)
The cyclic secondary amino skeleton and the branch-containing ester group are bonded via a carbon chain having a carbon number of m.

  In said formula (1), m represents carbon number which a carbon chain has. m is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 1 or more, and its upper limit is usually 4 or less, preferably 3 or less, more preferably 2 or less. Among these, m is preferably 1. When the value of m is 0, the solubility of the aminated fullerene in the alcohol becomes insufficient, and when it is too large, the polarity of the cyclic secondary amino skeleton is lowered, and sufficient solubility of the aminated fullerene of the present invention is exhibited. There is a possibility not to.

  Since the cyclic secondary amino skeleton and the branch-containing ester group are bonded via a carbon chain having a carbon number of m, usually both are bonded by a linking group containing the carbon chain. The molecular weight of the linking group containing a carbon chain is arbitrary as long as the effects of the present invention are not significantly impaired, but is usually 14 g / mol or more, and the upper limit is usually 56 g / mol or less, preferably 42 g / mol or less. More preferably, it is 28 g / mol or less. When the molecular weight is too large, the polarity of the cyclic secondary amino skeleton is lowered, and sufficient solubility of the aminated fullerene may not be exhibited. In addition, a connection group may be used individually by 1 type, and may be used 2 or more types by arbitrary ratios and combinations.

  In addition, the linking group containing a carbon chain may have not only a saturated bond but also an unsaturated bond as long as the effects of the present invention are not significantly impaired. The unsaturated bond may be a double bond or a triple bond. Moreover, you may have a double bond and a triple bond by arbitrary ratios and combinations.

  The linking group containing a carbon chain is arbitrary as long as the effects of the present invention are not significantly impaired, and among them, an alkylene group is preferable. Specific examples of the alkylene group include a methylene group, an ethylene group, and a 1,3-propylene group. Especially, as a coupling group containing a carbon chain, a methylene group is preferable.

  Further, the linking group containing a carbon chain may be substituted with a substituent unless the effects of the present invention are significantly impaired. Examples of the substituent include an alkyl group, an alkenyl group, an aryl group, an aralkyl group, a halogen atom, a hydroxy group, an alkoxy group, and an alkoxythio group. As for the substituents, one type may be substituted alone, or two or more types may be substituted in any ratio and combination.

The molecular weight of the substituent is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 15 g / mol or more, preferably 29 g / mol or more, more preferably 57 g / mol or more, and the upper limit is Usually, it is 200 g / mol or less, preferably 100 g / mol or less, more preferably 71 g / mol or less. If the molecular weight is too small, the effect may not be sufficient. If the molecular weight is too large, the molecular weight of R ¹ will increase, resulting in a relative decrease in the ratio of fullerene per unit weight. There is a possibility that the above characteristics are not fully developed.

  Furthermore, the substituent may have a ring as long as the effects of the present invention are not significantly impaired.

  The substituent may have not only a saturated bond but also an unsaturated bond as long as the effects of the present invention are not significantly impaired. The unsaturated bond may be a double bond or a triple bond. Moreover, you may have a double bond and a triple bond by arbitrary ratios and combinations.

(Specific structure of cyclic secondary amino group)
In the aminated fullerene of the present invention, specific examples of the structure of the cyclic secondary amino group include those having the following structures.

（なお、上記構造式中、「ｔＢｕ」はｔ−ブチル基を、「Ｍｅ」はメチル基を表す。）

(In the above structural formula, “tBu” represents a t-butyl group, and “Me” represents a methyl group.)

(Preferred embodiment of bond between fullerene and cyclic secondary amino group)
In the aminated fullerene of the present invention, the nitrogen atom of the cyclic secondary amino group and the fullerene are directly bonded. The number of cyclic secondary amino groups bonded to one fullerene is usually 1 or more, preferably 2 or more, more preferably 4 or more, and the upper limit is usually 10 or less, preferably 8 or less, more preferably 6 or less. It is. If the number of cyclic secondary amino groups is too small, the solubility of the aminated fullerene in alcohol may be low, and if too large, the conjugation of fullerene may be narrowed, and the beneficial properties of fullerene may be impaired. There is.

  In the aminated fullerene of the present invention, other atoms and / or functional groups may be bonded to the fullerene in addition to the cyclic secondary amino group. When an odd number of cyclic secondary amino groups are bonded to fullerene, usually other atoms and / or functional groups are also bonded to fullerene, and the total amount of bonds is an even number. On the other hand, even when an even number of ester-substituted cyclic secondary amino groups are bonded to the fullerene, other atoms and / or functional groups may be bonded to the fullerene. The other atoms and / or functional groups are arbitrary as long as the effects of the present invention are not significantly impaired, and examples thereof include a hydrogen atom, a hydroxyl group, and a divalent oxygen atom. As for other atoms and / or functional groups, one type may be bonded to the fullerene alone, or two or more types may be bonded to the fullerene in any ratio and combination.

  In the aminated fullerene of the present invention, one cyclic secondary amino group may be bonded to the fullerene alone, or two or more cyclic secondary amino groups may be bonded to the fullerene in an arbitrary ratio and combination. May be.

A preferred embodiment of the coupling between the fullerenes and the annular secondary amino group, fullerene C ₆₀ with the annular secondary amino group are four bound, further, tetra amino C ₆₀ to divalent oxygen atoms bonded - monoepoxide or fullerene C ₆₀ tetraamino C ₆₀ aforementioned cyclic secondary amino group is bonded to four is mentioned, particularly preferably tetra amino C ₆₀ can be selectively synthesized by a known production method - a monoepoxide.

（式（５）中、ＮＲ²は、それぞれ独立して、上記の環状２級アミノ基を表す。また、式（５）中、細線で表される炭素−炭素結合は、フラーレンを形成する炭素骨格が有する炭素−炭素結合を表す。） Tetraamino C ₆₀ - Of monoepoxide, tetra amino C ₆₀ having a partial structure represented by the following formula (5) on the fullerene - monoepoxide, since it selectively synthesized by known production methods, particularly preferred

(In Formula (5), each NR ² independently represents the above-mentioned cyclic secondary amino group. In Formula (5), the carbon-carbon bond represented by a thin line represents carbon forming fullerene. (Represents a carbon-carbon bond of the skeleton)

  Specific examples of the aminated fullerene having the partial structure of the above formula (5) include those having the following structures.

（なお、構造式中、「ｔＢｕ」は、ｔ−ブチル基を表す。）

(In the structural formula, “tBu” represents a t-butyl group.)

  The aminated fullerene of the present invention preferably has the above structure.

[2. Method for producing aminated fullerene]
The aminated fullerene of the present invention can be produced from an appropriate material by any known production method. For example, the aminated fullerene of the present invention is cyclic as a raw material for fullerene and aminated fullerene in the presence of visible light or hydroperoxide according to the method described in JP-A-2002-88075 or JP-A-2006-199674. It can be produced by reacting with an amine having a secondary amino group (hereinafter appropriately referred to as “cyclic secondary amine”). Specifically, for example, fullerenes and cyclic secondary amines are reacted in the presence of inorganic hydroperoxides such as hydrogen peroxide or organic hydroperoxides such as cumene hydroperoxide, or hydroperoxides are generated in the presence of oxygen molecules. Then, fullerene and a cyclic secondary amine are reacted. Especially, it is preferable to make fullerene and a cyclic | annular secondary amine react with presence of organic hydroperoxide from a viewpoint of an industrial manufacturing method.

  Hereinafter, a method for producing an aminated fullerene of the present invention by reacting fullerene with a cyclic secondary amine in the presence of an organic hydroperoxide (hereinafter referred to as “the production method of the present invention” as appropriate) will be described. However, the content described below is an example of the method for producing an aminated fullerene of the present invention, and the method for producing an aminated fullerene of the present invention is not limited to the content described below.

  In the production method of the present invention, from the viewpoint of suppressing side reactions, the fullerene is dissolved in a solvent, the cyclic secondary amine is further mixed, and then the organic hydroperoxide is mixed, whereby the aminated fullerene of the present invention is obtained. To manufacture.

(Fullerene)
Any fullerene can be used as long as the aminated fullerene of the present invention is obtained. Among these, [1. It is preferable to use the fullerene described in [Aminated Fullerene]. In addition, fullerene may be used individually by 1 type and may be used 2 or more types by arbitrary ratios and combinations.

(Cyclic secondary amine)
The cyclic secondary amine is optional as long as the aminated fullerene of the present invention can be obtained, and those capable of binding the above cyclic secondary amino group to the fullerene can be arbitrarily used. Examples thereof include those having a structure in which a hydrogen atom is bonded to a bond of the cyclic secondary amino group. A cyclic | annular secondary amine may be used individually by 1 type, and may be used 2 or more types by arbitrary ratios and combinations.

  The cyclic secondary amine can be usually synthesized by alkylating the nitrogen atom of a cyclic amine having two nitrogen atoms (that is, a cyclic amine having two NH groups on the ring). Specifically, for example, a cyclic secondary amine can be synthesized by reacting the cyclic amine with an alkyl halide. Hereinafter, a method for synthesizing a cyclic secondary amine by reacting the cyclic amine with an alkyl halide will be described in detail. The method for synthesizing a cyclic secondary amine is limited to the following contents. is not.

  The cyclic amine has two nitrogen atoms and is optional as long as the aminated fullerene of the present invention is obtained. The carbon number of the cyclic amine is usually the same as the carbon number of the cyclic secondary amino skeleton.

  Further, the molecular weight of the cyclic amine is usually 72 or more, preferably 86 or more, and the upper limit thereof is usually 200 or less, preferably 150 or less, more preferably 120 or less. If the molecular weight is too large, it may be difficult to obtain.

  Specific examples of the cyclic amine include piperazine, homopiperazine, imidazolidine and the like. Among these, piperazine and homopiperazine are preferable, and piperazine is more preferable.

  The cyclic amine may be substituted with a substituent as long as the aminated fullerene of the present invention is obtained. Examples of the substituent that may be substituted include a substituent that may be substituted on the cyclic secondary amino skeleton.

  Alkyl halides are usually those in which a halogen atom is bonded to the carbon chain to which the above-mentioned branch-containing ester group is bonded. Specific examples of the halogen atom include a chlorine atom, a bromine atom and an iodine atom. Among them, a chlorine atom, a bromine atom and an iodine atom are preferable, and a bromine atom is more preferable.

  Specific examples of the alkyl halide include α-bromoacetate-t-butyl, α-bromoacetate neopentyl, α-chloroacetate-t-butyl, β-bromopropionate-t-butyl, and the like. Bromoacetate-t-butyl and α-bromoacetate neopentyl are preferable from the viewpoint of reactivity, and α-bromoacetate-t-butyl is more preferable from the viewpoint of availability.

  When synthesizing a cyclic secondary amine using the above cyclic amine and the above alkyl halide, a linking group containing the above carbon chain is usually attached to one of the nitrogen atoms of the cyclic amine. A mixture of a monoalkylated form of the bonded cyclic amine and a dialkylated form of the cyclic amine in which the linking group containing the above carbon chain is bonded to two nitrogen atoms is obtained. In the production method of the present invention, as long as the aminated fullerene of the present invention is obtained, the monoalkylated product may be separated and purified from the mixture and used as a cyclic secondary amine, or the mixture may be used as a cyclic secondary amine. It may be used.

  The amount of the monoalkylated compound contained in the above mixture varies depending on the ratio of the cyclic amine and alkyl halide used in the synthesis and the reaction conditions, but is usually 10 mol% or more, preferably 20 mol% or more, more preferably 30 mol% or more, and the upper limit is usually 99 mol% or less, preferably 95 mol% or less, more preferably 90 mol% or less. If the amount of the monoalkylated product is too small, it is necessary to use a large amount of reagent in the addition reaction to fullerene, and thus it may require a great deal of effort to remove the dialkyl product after the reaction. If too much, a great deal of labor may be required for the synthesis and separation of the monoalkylated product.

  The raw materials, reaction conditions, reaction apparatus, and the like when synthesizing the cyclic secondary amine other than those described above can be arbitrarily determined as long as the aminated fullerene of the present invention is obtained.

(Organic hydroperoxide)
Any organic hydroperoxide can be used as long as the aminated fullerene of the present invention can be obtained. One hydrogen atom contained in hydrogen peroxide having the structure of the following formula (6) is converted into an organic group R. It is preferable to use a compound substituted with ³ . In addition, an organic hydroperoxide may be used individually by 1 type, and may be used 2 or more types by arbitrary ratios and combinations. Further, for example, an organic hydroperoxide and a raw material for producing an organic hydroperoxide (hereinafter referred to as “organic hydroperoxide precursor” as appropriate) may be used in combination, such as cumene hydroperoxide and cumene described later.

（式（６）中、Ｒ³は任意の有機基を表す。）

(In formula (6), R ³ represents any organic group.)

In formula (6), R ³ represents any organic group as long as the aminated fullerene of the present invention is obtained. Among these, R ³ is preferably a hydrocarbon group, and more preferably a hydrocarbon group having a tertiary carbon atom. The carbon number of R ³ is usually 1 or more, preferably 4 or more, more preferably 5 or more, and the upper limit is usually 15 or less, preferably 12 or less, more preferably 10 or less. When R ³ has too many carbon atoms, the hydroperoxide portion per unit weight decreases, and the amount of organic hydroperoxide used increases and a large amount of by-products may be generated.

The molecular weight of R ³ is arbitrary as long as the aminated fullerene of the present invention is obtained, but is usually 50 g / mol or more, preferably 80 g / mol or more, more preferably 100 g / mol or more, and the upper limit is Usually, it is 500 g / mol or less, preferably 400 g / mol or less, more preferably 300 g / mol or less. When the molecular weight is too large, the hydroperoxide portion per unit weight decreases, and the amount of organic hydroperoxide used increases and a large amount of by-products may be generated.

Furthermore, R ³ may have a ring as long as the effects of the present invention are not significantly impaired.

Specific examples of R ³ include t-butyl group, neopentyl group, t-hexyl group, cumyl group and the like. Of these, t-butyl, neopentyl, t-hexyl and cumyl are preferred from the viewpoint of stability and ease of handling, and t-butyl and cumyl are preferred from the viewpoint of industrial availability. Groups are more preferred.

R ³ may have a substituent as long as the aminated fullerene of the present invention is obtained. Examples of the substituent that may be included include an alkyl group and an aryl group. As for the substituents, one type may be substituted alone, or two or more types may be substituted in any ratio and combination.

  The molecular weight of the substituent is arbitrary as long as the aminated fullerene of the present invention is obtained, but is usually 15 g / mol or more, preferably 50 g / mol or more, and the upper limit is usually 200 g / mol or less, preferably Is 150 g / mol or less. When the molecular weight is too large, the hydroperoxide portion per unit weight is reduced, the amount of organic hydroperoxide used is increased, and a large amount of by-products may be generated.

  Furthermore, the substituent may have a ring as long as the aminated fullerene of the present invention is obtained.

In addition, these substituents may be further substituted in multiple by one or more substituents. Examples of the substituent that can be substituted include those that can be substituted on the above R ³ .

For example, when R ³ is a hydrocarbon group having a tertiary carbon atom, the organic hydroperoxide is usually produced from a compound having the structure of the following formula (7) and an oxygen atom by any known production method. can do.

For example, cumene hydroperoxide in which R ³ is a cumyl group can usually be produced from cumene and an oxygen atom by any known production method. In the produced cumene hydroperoxide, unless the amination reaction of fullerene, which will be described later, is significantly prevented, it is usually 5% by weight, preferably 7% by weight or more, more preferably 10% by weight or more, and the upper limit is Usually, 30% by weight or less, preferably 20% by weight or less, more preferably 15% by weight or less of unreacted cumene may be contained. If the amount of unreacted cumene is too small, the mixture of cumene hydroperoxide and cumene may become unstable and explode during handling, etc., if too much, waste after reaction may increase. There is.

(Other ingredients)
In the production method of the present invention, as long as the aminated fullerene of the present invention is obtained, components other than the above-mentioned fullerene, cyclic secondary amine and organic hydroperoxide (hereinafter referred to as “other components” as appropriate) are included in the reaction system. It may be included. Examples of components that may be included include tertiary amines such as alkanes and triethylamine, tertiary alcohols such as pyridine and t-butanol, and derivatives thereof. Other components may be used alone or in combination of two or more in any ratio and combination.

(solvent)
Fullerenes, cyclic secondary amines, organic hydroperoxides and other components used as necessary are usually dissolved in a solvent and reacted. The kind and amount of the solvent used are arbitrary as long as the aminated fullerene of the present invention is obtained. However, usually, a solvent in which fullerene, cyclic secondary amine and organic hydroperoxide are dissolved is used. In addition, a solvent may be used individually by 1 type and may be used 2 or more types by arbitrary ratios and combinations.

  As the type of the solvent, from the viewpoint of high solubility in fullerene, there are aromatic solvents such as aromatic hydrocarbon solvents and aromatic halogenated hydrocarbon solvents (hereinafter referred to as “aromatic solvents” as appropriate). preferable.

  Specific examples of the aromatic hydrocarbon solvent include benzene, toluene, xylene, ethylbenzene, trimethylbenzene, or derivatives thereof.

  Specific examples of the aromatic halogenated hydrocarbon solvent include chlorobenzene, bromobenzene, dichlorobenzene, trichlorobenzene, or derivatives thereof.

  When using an aromatic solvent as a solvent, it is preferable to use it as a mixed solvent in which a polar solvent is mixed with an aromatic solvent, from the viewpoint of greatly improving the reaction rate.

Here, the polar solvent in the production method of the present invention is a solvent having a large polarity. Specifically, the value of the relative dielectric constant ε _r representing the polarity of the solvent is usually 25 or more, preferably 30 or more, more preferably 35 or more, and the upper limit is usually 200 or less. The value of the relative dielectric constant ε _r is described in, for example, Solvents and Solvent Effects in Organic Chemistry 2nd Ed. 1990, VCH p. 59, which is unique to the compound.

The dielectric constant is a ratio (D / E) between the electric flux density D and the electric field E given thereby, and is a coefficient indicating the relationship between the electric charge in the substance and the force given thereby. Each material has a specific dielectric constant, and this value is determined by how the atoms or molecules in the material respond when an electric field is applied from the outside (ie, the manner of dielectric polarization). If ε ₀ is the dielectric constant of vacuum (8.854 × 10 ⁻¹² F / m), ε / ε ₀ is referred to as the relative dielectric constant and is represented by ε _r . The relative dielectric constant ε _r of various polar organic solvents is as follows (extracted from “Table A-1” in Solvents and Solvent Effects in Organic Chemistry 2nd Ed. 1990, VCH, p. 408-p. 410).

N-methylformamide 182.4
N, N-dimethylformamide 36.71
N, N-dimethylacetamide 37.78
N-methylpyrrolidone 32.2
Dimethyl sulfoxide 46.45
Sulfolane 43.3
N, N′-dimethylpropyleneurea 36.12
Hexamethylphosphoric triamide 29.6

  Specific examples of the polar solvent to be mixed include sulfoxides such as dimethyl sulfoxide and diphenyl sulfoxide; sulfones such as dimethyl sulfone and sulfolane; N, N-dimethylformamide, N, N-dimethylacetamide, N-methylformamide, formamide, Amides such as N-methylpyrrolidone; ureas such as N, N′-dimethylpropyleneurea; phosphoric acid amides such as hexamethylphosphoramide; phosphorous amides such as hexamethylphosphoric triamide . Among them, sulfoxides and amides are preferable from the viewpoint of the effect of mixing with a polar solvent, and dimethyl sulfoxide and N, N-dimethylformamide are more preferable from the viewpoint of industrial availability.

  The amount of the polar solvent to be mixed varies depending on the type of the polar solvent, and cannot be generally specified. However, the amount is usually preferably 1% by volume or more, more preferably 5% by volume or more, particularly preferably based on the aromatic solvent. 10 vol% or more, and the upper limit thereof is preferably 99 vol% or less, more preferably 50 vol% or less, and particularly preferably 40 vol% or less. When the amount of the polar solvent is too small, there is a possibility that the effect of mixing the polar solvent may not be sufficiently obtained. When the amount is too large, the concentration of the aromatic solvent in the mixed solvent becomes low, and the fullerene, the reaction intermediate, etc. There is a possibility that the solubility in a solvent is lowered.

  Moreover, it is preferable to use a polar solvent in which the aromatic solvent and the polar solvent are uniformly mixed when mixed with the aromatic solvent at the above concentration.

(Amount used for each component)
The use amounts of fullerene, cyclic secondary amine and organic hydroperoxide are arbitrary as long as the aminated fullerene of the present invention is obtained. Also, the amount of solvent used and the amount of other components used are arbitrary as long as the aminated fullerene of the present invention is obtained.

  Among them, the amount of fullerene used varies depending on the type of solvent and cannot be generally stated, but is usually 4 mg or more, preferably 5 mg or more, more preferably 6 mg or more, and the upper limit is usually 20 mg per 1 mL of solvent. The amount is preferably 18 mg or less, more preferably 16 mg or less. If the amount of fullerene used is too small, the productivity may decrease due to the use of a large amount of solvent, and if it is too large, side reactions may become prominent.

  The amount of cyclic secondary amine used is usually 4 times mol or more, preferably 4.5 times mol or more, more preferably 5 times mol or more, and the upper limit is usually 16 times mol or less with respect to 1 mol of fullerene. , Preferably 12 times mol or less, more preferably 10 times mol or less. If the amount of cyclic secondary amine used is too small, the reaction rate may be slow, and if too large, the cost may be high.

  Furthermore, the amount of the organic hydroperoxide used is usually 3 times mol or more, preferably 3.2 times mol or more, more preferably 3.5 times mol or more with respect to 1 mol of fullerene. Double mole or less, preferably 5 moles or less, more preferably 4.5 moles or less. If the amount of the organic hydroperoxide used is too small, the reaction may be slow, and if it is too large, side reactions will become prominent and excess organic hydroperoxide will remain, possibly causing an explosion.

  Furthermore, the amount of other components used varies depending on the type of other components and cannot be generally stated, but is usually 1 mg or more, preferably 3 mg or more, more preferably 5 mg or more, per 1 mL of solvent. The upper limit is usually 100 mg or less, preferably 50 mg or less, more preferably 10 mg or less. If the amount of other components used is too small, the effects of the other components may not be sufficiently exerted, and if too large, side reactions may become prominent.

(Reaction conditions)
In a production method using an organic hydroperoxide, since the reaction usually proceeds without irradiating light, the reaction system may not be actively irradiated with light. Therefore, in the method for producing an aminated fullerene of the present invention, the presence or absence of light irradiation is not particularly limited. Specifically, the reaction can be performed using a reaction vessel made of a light-transmitting material such as glass, or the reaction vessel can be reacted using a reaction vessel made of a material that hardly transmits light such as metal. Good.

  The reaction temperature is arbitrary as long as the aminated fullerene of the present invention is obtained, but is usually 0 ° C. or higher, preferably 10 ° C. or higher, more preferably 15 ° C. or higher, and the upper limit is usually 50 ° C. or lower, preferably Is 35 ° C. or lower, more preferably 30 ° C. or lower. If the reaction temperature is too low, the reaction may be slow, and if too high, side reactions may become significant.

  The reaction time is arbitrary as long as the aminated fullerene of the present invention is obtained, but is usually 1 hour or more, preferably 3 hours or more, more preferably 5 hours or more, and the upper limit is usually several days or less. Preferably it is 3 days or less, More preferably, it is 2 days or less. If the reaction time is too long, industrial production efficiency may be reduced.

  The reaction atmosphere is arbitrary as long as the aminated fullerene of the present invention is obtained, but it is usually carried out under an inert gas. Specific examples of the inert gas include nitrogen and argon. An inert gas may be used individually by 1 type, and may be used 2 or more types by arbitrary ratios and combinations.

  The order of mixing fullerene, cyclic secondary amine, organic hydroperoxide, and other components used as necessary is arbitrary as long as the aminated fullerene of the present invention is obtained. Among these, from the viewpoint of suppressing side reactions, it is preferable to produce the aminated fullerene of the present invention by dissolving fullerene in a solvent, further mixing the above-described cyclic secondary amine, and then mixing the organic hydroperoxide. At this time, when the organic hydroxy peroxide is a chemically unstable compound, it is preferably supplied into the reaction system so that the organic hydroxy peroxide is not decomposed.

The produced aminated fullerene of the present invention can be confirmed by any known method. For example, the reaction solution is subjected to high performance liquid chromatography (HPLC) using an octadecyl silica gel (ODS) column. Can be confirmed. Also, for example, ¹
The presence of the aminated fullerene of the present invention can also be confirmed by 1 H-NMR.

(Isolation of aminated fullerene)
The aminated fullerene of the present invention can be isolated from the reaction solution after the reaction, using any known method. Especially, it is preferable to isolate by the procedure described below. However, the content described below is an example of a means for isolating, and the means for isolating is not limited to the following content.

  First, polar compounds such as a polar solvent are usually removed by washing the reaction solution with water. Crystallization is performed by concentrating the solution after washing and adding a poor solvent, and the aminated fullerene of the present invention can usually be obtained as a powder.

  Here, as a concentration method, for example, a rotary evaporator can be used under reduced pressure conditions. Examples of the poor solvent used for crystallization include water; aliphatic hydrocarbon solvents such as pentane, hexane, and heptane; nitrile solvents such as acetonitrile; and the like. A poor solvent may be used individually by 1 type, and may be used 2 or more types by arbitrary ratios and combinations. Moreover, other conditions, such as the usage-amount of a poor solvent, are arbitrary as long as the amination fullerene of this invention is obtained.

  When isolated by the above procedure, the yield depends on the type of ester-substituted cyclic secondary amine used, but is usually 50% or more, preferably 60% or more, more preferably 70% or more, and its upper limit. Is usually 99% or less, preferably 95% or less, more preferably 90% or less. If the yield is too low, the cost may increase.

[3. Suitable Field of Use of Aminated Fullerene of the Present Invention]
The aminated fullerene of the present invention exhibits high solubility in alcohol. Examples of the alcohol include lower alcohols such as methanol, ethanol, propanol, butanol, etc. Among them, lower alcohols are preferable, among which methanol and ethanol are more preferable, and methanol is particularly preferable. As a specific numerical range of high solubility, the aminated fullerene of the present invention is usually 1% by weight or more, preferably 1.2% by weight or more, more preferably, with respect to methanol suitably used as a hydrophilic organic solvent. It dissolves uniformly at a concentration of 2% by weight or more, and its upper limit is usually 10% by weight or less, preferably 5% by weight or less, more preferably 2.5% by weight or less. Therefore, the solution in which the aminated fullerene of the present invention is dissolved in alcohol is suitably used for an electronic conductive material used as a thin film by applying it on a substrate by spin coating or the like, as well as physiological products such as cosmetics, pharmaceuticals, and biomaterials. It can also be suitably used for applications such as active substances and resin additives.

  In addition, the aminated fullerene of the present invention exhibits high solubility in an ester solvent, depending on conditions such as the dissolution temperature. Specifically, the aminated fullerene of the present invention is usually 5% by weight or more, preferably 10% by weight or more, with respect to the propylene glycol-1-monomethyl ether-2-acetate solution suitably used for electronic materials. It is preferably 20% by weight or more, and the upper limit thereof is usually 50% by weight or less, preferably 40% by weight or less, more preferably 30% by weight or less. For this reason, a solution dissolved in a high concentration in an ester solvent can be suitably used for an electron conductive material used as a thin film by applying it on a substrate by spin coating or the like.

  The aminated fullerene of the present invention can be used for the aforementioned applications. Hereinafter, some examples of applications will be described more specifically. However, the applications in which the function of the aminated fullerene of the present invention can be exhibited are not limited to the following descriptions.

[Photoresist application]
Conventionally, a photoresist is a composition in which a resin component such as a (meth) acrylic, polyhydroxystyrene, or novolak resin is combined as a film forming component with an acid generator or a photosensitizer that generates an acid upon exposure. Is widely used. Since the aminated fullerene of the present invention is usually highly soluble in a solvent used for a photoresist, it can be combined with the photoresist at a higher concentration without using a special solvent. Moreover, it is possible to form a resist film with aminated fullerene alone.
As described above, when the aminated fullerene of the present invention is used in the field of photoresist, having a fullerene skeleton has high heat resistance and high etching resistance as a superaromatic molecule, and can reduce edge roughness. Yes, high-resolution photoresist can be reproduced. In addition, the film formed using the aminated fullerene of the present invention also has a function as an antireflection film, and thus is excellent as one layer of a multilayer film, particularly as an antireflection film or a coating type mask material (hard mask). It is expected to demonstrate its functions. Further, since the fullerene film or fullerene-containing film obtained by heating this film also has a function as an antireflection film, the antireflection film or coating-type mask material (hard mask) is used as one layer of the multilayer film. ) Is expected to exhibit excellent functions.

[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 aminated fullerene of the present invention has a high concentration in the thermoplastic polymer without using a special solvent because of its high solubility in the solvent used for the thermoplastic polymer and curable material. It is possible to fill with.

  As described above, when the aminated fullerene of the present invention is used in the nanoimprint method, the aminated fullerene of the present invention has high solubility in a solvent, so that aggregation of the aminated fullerene of the present invention in the thermoplastic polymer is suppressed. It becomes molecular dispersion. For this reason, it is possible to realize high resolution. Furthermore, a fullerene dispersion material obtained by heating the material can be used in the same manner, and high resolution can be realized. Furthermore, the mechanical strength, heat resistance and etching resistance of the transfer layer can be improved by using the aminated fullerene of the present invention or the solution of the present invention for the nanoimprint method. Can be greatly improved.

[For low dielectric constant insulating 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 aminated fullerene of the present invention can be complexed with other materials at a higher concentration without using a special solvent because of its high solubility in the solvent used for the above-mentioned applications. It is also possible to form a film with an aminated fullerene alone. At this time, the aminated fullerene 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 the 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 and excellent performance that has never been obtained. Furthermore, a fullerene-containing material or fullerene film obtained by heating the composite material or the aminated fullerene film can be used in the same manner, and it has been possible to realize a low dielectric constant interlayer insulating film with excellent performance that has never been achieved before. It becomes possible.

[Solar cell applications]
Although organic solar cells have many advantages over silicon-based inorganic solar cells, the energy conversion efficiency is low and the practical level has not been sufficiently achieved. In order to overcome this problem, a bulk heterojunction organic solar cell having an active layer in which a conductive polymer as an electron donor and a fullerene and a fullerene derivative as an electron acceptor are recently proposed has been proposed. Yes. In this bulk heterojunction organic solar cell, the conductive polymer and the fullerene derivative are mixed at the molecular level, and as a result, a very large interface has been successfully created, and the conversion efficiency has been greatly improved.
Since the aminated fullerene of the present invention has high solubility in the solvent used in the above-mentioned applications, it is easy to form an efficient bulk heterojunction structure with a p-type semiconductor. In addition, the aminated fullerene of the present invention essentially has the properties of fullerene as an n-type semiconductor. Therefore, an extremely high performance organic solar cell can be realized by using the aminated fullerene of the present invention. Moreover, after forming a bulk heterostructure, aminated fullerene may be converted into fullerene by heating or the like. Furthermore, by utilizing this high solubility, it is possible to control layer separation from electron donor layers such as conductive polymers, and to control morphology such as alignment orientation and fine packing of derivative molecules, thereby improving characteristics. In addition, it provides great flexibility in device design. Also, in terms of production, it is possible to easily realize a large area at low cost by ordinary printing methods, ink jet printing, and spraying.

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

[Uses as raw material intermediates]
Using the aminated fullerene of the present invention as a starting material, a fullerene derivative having a new function can be produced through a step of converting an ester group on a cyclic secondary amino group by reaction. Hereinafter, representative examples of the conversion method will be described, but the present invention is not limited to the following examples.
(1) The aminated fullerene of the present invention is reacted with an alkali to be hydrolyzed.
(2) The aminated fullerene of the present invention is transesterified by reacting with an ester or alcohol.
(3) The aminated fullerene of the present invention is reduced by reacting with a reducing agent.

  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 following description, tBu represents a t-butyl group.

[Example 1]
[Synthesis of amine]
Piperazine (8.0 g, 93 mmol) was dissolved in 80 mL of ethanol to obtain a uniform solution. Α-Bromoacetate-t-butyl (5.2 g, 27 mmol) was slowly added dropwise thereto. After completion of dropping, the mixture was stirred for 23 hours, charged with ion-exchanged water (150 mL), and concentrated under reduced pressure. After evaporating ethanol as a solvent, ion-exchanged water (150 mL) was added to the remaining aqueous solution, and after confirming that it was not acidic, extraction with dichloromethane (300 mL) was performed. The extracted solution was dried over magnesium sulfate and concentrated to obtain 4.66 g of a mixture of t-butoxycarbonylmethylpiperazine and di (t-butoxycarbonylmethyl) piperazine as a by-product.

[Synthesis of aminated fullerene]
Under a nitrogen gas atmosphere, fullerene C ₆₀ (1.0 g, 1.39 mmol) was dissolved in paraxylene (20 mL), stirred for 10 minutes, added with dimethyl sulfoxide (5 mL), and stirred for 1 hour. The above mixture containing t-butoxycarbonylmethylpiperazine (2.3 g, the content of t-butoxycarbonylmethylpiperazine was 11.1 mmol calculated from the intrinsic ratio) was mixed with 5 mL of paraxylene, and the purity of 84 % Cumene hydroperoxide (880 mg, 4.86 mmol) was mixed with 5 mL para-xylene. It was subjected to stirring at ambient temperature, to confirm the disappearance of the raw material C ₆₀ after 47 hours. Paraxylene (100 mL) was added, and the organic phase was washed once with a mixture of ion-exchanged water (100 mL) and acetonitrile (20 mL), and then a mixture of 0.5 N hydrochloric acid (100 mL) and acetonitrile (20 mL). And then washed once with a mixed solution of ion-exchanged water (100 mL) and acetonitrile (20 mL). Sodium sulfate was added for drying, followed by filtration and concentration to about 5 mL. The precipitate obtained by mixing 200 mL of acetonitrile with stirring was filtered off, washed with acetonitrile, and then dried under reduced pressure at room temperature for 3 hours, whereby an aminated fullerene having a structure represented by the following formula (8) (tetra ( t- butoxycarbonyl-methyl-piperazino) C ₆₀ - to give a monoepoxide) 2.02 g (95% yield quadruple adduct conversion). As a result of HPLC analysis using an ODS column using a toluene / methanol mixed solvent as an eluent, the purity of the product was 46%.

  When 100 mg of the obtained aminated fullerene was weighed and made into a 10 g methanol solution, it was uniformly dissolved. Moreover, when it was set as a 2g methanol solution, it did not melt | dissolve uniformly, but when the slurry was filtered with a 0.45 micrometer filter and the filtrate was quantified by HPLC, it was 2.5 weight% of density | concentration. Even after this solution was allowed to stand at room temperature for 7 days under air, it kept a uniformly dissolved state. Further, 100 mg of the obtained aminated fullerene was weighed and added with a propylene glycol-1-monomethyl ether-2-acetate solution (hereinafter referred to as “PGMEA” as appropriate) to make 2.0 g, and then uniformly dissolved. . This solution was kept in a uniformly dissolved state even after being left at room temperature for 30 days under air.

[Example 2]
[Synthesis of amine]
Homopiperazine (5.0 g, 50 mmol) was dissolved in 80 mL of ethanol to obtain a uniform solution. Α-Bromoacetate-t-butyl (2.4 g, 12 mmol) was slowly added dropwise thereto. After completion of dropping, the mixture was stirred for 23 hours, charged with ion-exchanged water (150 mL), and concentrated under reduced pressure. After evaporating ethanol as a solvent, ion-exchanged water (150 mL) was added to the remaining aqueous solution, and after confirming that it was not acidic, extraction with dichloromethane (300 mL) was performed. The extracted solution was dried over magnesium sulfate and concentrated to obtain 2.57 g of a mixture of t-butoxycarbonylmethyl homopiperazine and di (t-butoxycarbonylmethyl) homopiperazine as a by-product.

[Synthesis of aminated fullerene]
Under a nitrogen gas atmosphere, fullerene C ₆₀ (1.0 g, 1.39 mmol) was dissolved in paraxylene (20 mL), stirred for 10 minutes, dimethyl sulfoxide (50 mL) was added, and the mixture was stirred for 1 hour. After mixing the above mixture containing t-butoxycarbonylmethyl homopiperazine (2.4 g, the content of t-butoxycarbonylmethyl homopiperazine was 11.1 mmol calculated from the intrinsic ratio) with para-xylene, the purity was 84 % Cumene hydroperoxide (880 mg, 4.86 mmol) was mixed with 20 mL para-xylene. Was subjected to stirring at room temperature, disappearance of the raw material was confirmed C ₆₀ after 21 hours. The organic phase is washed once with a mixture of ion-exchanged water (200 mL) and acetonitrile (40 mL), then with a mixture of 0.5 N hydrochloric acid (200 mL) and acetonitrile (40 mL), and further ion-exchanged water. Washed once with a mixture of (200 mL) and acetonitrile (40 mL). Sodium sulfate was added for drying, followed by filtration and concentration to about 5 mL. The precipitate obtained by mixing 200 mL of acetonitrile with stirring was filtered off, washed with acetonitrile, and then dried under reduced pressure at room temperature for 3 hours, whereby an aminated fullerene having a structure represented by the following formula (9) (tetra ( t- butoxycarbonyl-methyl homo-piperazino) C ₆₀ - to give a monoepoxide) 2.29 g (104% yield quadruple adduct conversion). As a result of HPLC analysis using an ODS column with a toluene / methanol mixed solvent as an eluent, the purity of the product was 76%.

  When 100 mg of the obtained aminated fullerene was weighed and made into a 10 g methanol solution, it was uniformly dissolved. Moreover, when it was set as a 2g methanol solution, it did not melt | dissolve uniformly, but when the slurry was filtered with a 0.45 micrometer filter and the filtrate was quantified by HPLC, it was 2.5 weight% of density | concentration. Even after this solution was allowed to stand at room temperature for 7 days under air, it kept a uniformly dissolved state. Moreover, when 100 mg of the obtained aminated fullerene was weighed and PGMEA was added to make 2.0 g, it was dissolved uniformly. This solution was kept in a uniformly dissolved state even after being left at room temperature for 30 days under air.

[Comparative Example 1]
According to the method described in JP-A 2006-199674, an aminated fullerene (tetra (t-butoxycarbonylmethylhomopiperazino) C ₆₀ -monoepoxide) having a structure represented by the following formula (10) was synthesized. When 100 mg of the obtained aminated fullerene was weighed and PGMEA was added to make 2.0 g, it was uniformly dissolved. This solution was kept in a uniformly dissolved state even after being left at room temperature for 30 days under air. On the other hand, when 100 mg of the obtained aminated fullerene was weighed and made into a 10 g methanol solution, it did not dissolve. When this slurry was filtered with a 0.45 μm filter, the filtrate was colorless, so it was confirmed that the aminated fullerene was not dissolved in the filtrate. Further, when the filtrate was quantified by HPLC, tetra (t-butoxycarbonylmethylhomopiperazino) C ₆₀ -monoepoxide was not detected, and it was confirmed that the aminated fullerene was not dissolved in the filtrate. .

[Comparative Example 2]
According to the method described in JP-A-2006-199674, an aminated fullerene (tetra (4- (2-hydroxyethyl) piperidino) C ₆₀ -monoepoxide) having a structure represented by the following formula (11) was synthesized. When 100 mg of the obtained aminated fullerene was weighed and made into a 10 g methanol solution, it did not dissolve despite having a hydroxyl group in the molecule. When this slurry was filtered with a 0.45 μm filter, the filtrate was colorless, so it was confirmed that the aminated fullerene was not dissolved in the filtrate. Moreover, when 100 mg of aminated fullerene was weighed and PGMEA was added to make 10 g, it did not dissolve. When this slurry was filtered with a 0.45 μm filter, the filtrate was colorless, so it was confirmed that the aminated fullerene was not dissolved in the filtrate. Further, when the above-mentioned two kinds of filtrates were quantified by HPLC, tetra (4- (2-hydroxyethyl) piperidino) C ₆₀ -monoepoxide was not observed in any of them, and the aminated fullerene was found in any of the filtrates. Was not dissolved.

  The aminated fullerene of the present invention exhibits high solubility in alcohol. Therefore, the solution in which the aminated fullerene of the present invention is dissolved in alcohol is suitably used for the application of an electronic conductive material used as a thin film by applying it on a substrate by spin coating or the like. It can also be suitably used for applications such as physiologically active substances and resin additives.

Claims (8)

Ring-shaped secondary amino group of structures represented by the following formula (1), characterized in that directly bonded to the fullerene, aminated fullerenes.

(In the formula (1), m and n each independently represent an integer of 1 or more and 4 or less. E is an optionally substituted carbon atom having one or more branches. the. R _4, R ₅ representing an ester group containing 4 to 10 alkyl groups, each independently, a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an aralkyl group, a halogen atom, hydroxy group, alkoxy group or, R ₆ and R ₇ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an aralkyl group, a halogen atom, a hydroxy group, an alkoxy group, or an alkoxythio group. The aminated fullerene according to claim 1, wherein the ester group is an ester group having one or more structures selected from the group consisting of the following formulas (2), (3) and (4).

(In formulas (2) to (4), each R ¹ independently represents an alkyl group having 4 or more and 10 or less carbon atoms, which may have a substituent and has one or more branches .) The aminated fullerene according to claim 2, wherein R ¹ is a t-butyl group and / or a neopentyl group. The aminated fullerene according to claim 1, wherein n is 2 in the formula (1). The aminated fullerene according to claim 1, wherein m is 1 in the formula (1).   R ₆ , The R ₇ Are each independently a hydrogen atom or an alkyl group, alkenyl group, aryl group, aralkyl group, halogen atom, hydroxy group, alkoxy group, or alkoxythio group of 15 g / mol to 200 g / mol.
The aminated fullerene according to any one of claims 1 to 5, wherein The fullerene is C ₆₀ having 60 carbon atoms ;
The fullerene is a tetraamino C ₆₀ -monoepoxide in which four cyclic secondary amino groups having a structure represented by the above formula (1) are bonded and a divalent oxygen atom is bonded. Item 7. The aminated fullerene according to any one of Items 1 to 6 . The aminated fullerene according to claim 7 , wherein the tetraamino C ₆₀ -monoepoxide has a partial structure represented by the following formula (5) on the fullerene.

(Carbon in the formula (5), NR ² each independently represent a ring-shaped secondary amino groups of the structure represented by the above formula (1). Further, in the formula (5), I represented by the thin line -A carbon bond represents the carbon-carbon bond which the carbon skeleton which forms fullerene has.)