JP2007291000A - Fullerene derivative having magnetism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fullerene derivative having strong magnetism applicable to a material for an electric device, a functional molecular material, various kinds of solvents for reaction, and the like. <P>SOLUTION: The fullerene derivative having the chemical structure represented by formula (2) has an ion bond site on the skeleton of the fullerene molecule, and the strong magnetism superior to that of fullerene (C<SB>60</SB>) being a parent body. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an organic salt that can be preferably applied to materials for electrical devices, functional molecular materials, various reaction solvents, and the like, and more particularly to a fullerene derivative having magnetism.

In 1985, Kroto & Smalley et al. Demonstrated the existence of C ₆₀ and C _{70 for} the first time by the so-called “laser ablation method” in which a graphite rod was irradiated with a laser in a concentrated manner. However, since the amount produced was extremely small that could only be measured with a mass spectrometer, no knowledge was obtained about the structure and physical properties of C ₆₀ and C ₇₀ . 1990, Kretschmer (Kratschmer) et al., For the first time succeeded in generating and recovery of C _60, C ₇₀ of gram-order by contact arc method using a rod of graphite, C _60, which is said to soccer ball-shaped, a rugby ball shape, It demonstrated the structure of C ₇₀ (for example, as described in J.Phys.Chem.1990,94,8634-8636). Here, a method is adopted in which a large current is applied to the graphite base electrode while pressing the tapered graphite rod with the elastic force of the spring. For C _60, it is possible to synthesize various organic derivatives and organometallic derivatives, and applications are considered, such that for electrical devices for materials and functional molecular materials. However, due to the lack of reactivity, at present, the synthesis of hydrides of C ₆₀ H ₁₈ and C ₆₀ H ₃₆ , the synthesis of C ₆₀ derivatives by nucleophilic addition reaction to the C ₆₀ surface of amines, the platinum complex C ₆₀ Pt ( Only a few examples such as synthesis of PPh ₃ ) ₂ have been reported (see Patent Document 1).
JP-A-5-221623.

  An object of this invention is to provide the fullerene derivative which has strong magnetism applicable to the material for electrical devices, and a functional molecular material.

As a result of intensive studies, the present inventors have achieved the above object by using a fullerene derivative having an ionic bond site on the fullerene molecular skeleton.
That is, the present invention is a fullerene derivative having a chemical structure represented by the following general formula (1).

（式（１）中、フラーレン基の炭素数は６０であり、ｘは１〜１０の整数、ｙは１〜２０の整数、ｚは１〜２０の整数、ｂは１〜２０の整数、ｃは１〜２０の整数を示す。
Ｒ_A、Ｒ_B、Ｒ_Cは１価の基で、水素、脂肪族炭化水素基、芳香族炭化水素基、カルボン酸基、エステル基、エーテル基、アシル基およびアミノ基からなる群から選ばれる１種類以上の化学構造を含み、枝分かれや置換基を有しても良い。
Ｌ^-は、対イオン（アニオン成分）であり、Ｉ^-、Ｂｒ^-、ＡｌＣｌ₄ ^-、ＢＦ₄ ^-、ＰＦ₆ ^-、ビス（トリフルオロメチルスルホニル）イミドアニオン、ＣＨＦ₂−ＣＦ₂−ＣＨ₂ＯＳＯ₃ ^-原子団、ＣＨＦ₂−（ＣＦ₂）₃−ＣＨ₂ＯＳＯ₃ ^-原子団、ＣＦ₃−（ＣＦ₂）₂−ＣＨ₂ＯＳＯ₃ ^-原子団およびＣＦ₃−（ＣＦ₂）₆−ＣＨ₂ＯＳＯ₃ ^-原子団からなる群から選ばれる１種類以上の原子団を含むことができる。）

(In Formula (1), carbon number of a fullerene group is 60, x is an integer of 1-10, y is an integer of 1-20, z is an integer of 1-20, b is an integer of 1-20, c Represents an integer of 1-20.
R _A , R _B and R _C are monovalent groups selected from the group consisting of hydrogen, aliphatic hydrocarbon groups, aromatic hydrocarbon groups, carboxylic acid groups, ester groups, ether groups, acyl groups and amino groups. It may contain one or more types of chemical structures and may have branches or substituents.
L ⁻ is a counter ion (anion component), and I ⁻ , Br ⁻ , AlCl ₄ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , bis (trifluoromethylsulfonyl) imide anion, CHF ₂ —CF ₂ —CH ₂ OSO. ₃ ^- _{atomic, CHF 2 - (CF 2)} 3 -CH 2 OSO 3 - _{atomic, CF 3 - (CF 2)} 2 -CH 2 OSO 3 - atomic and _{CF 3 - (CF 2) 6} -CH 2 OSO ₃ ^- may comprise one or more atomic groups selected from the group consisting of atomic. )

  Moreover, it is preferable that this invention is a fullerene derivative which has a chemical structure represented by following formula (2). Fullerene derivatives having the chemical structural formula of formula (2) are particularly preferable because they exhibit ferromagnetism.

（式（２）中、フラーレン基の炭素数は６０である。）

(In Formula (2), the carbon number of the fullerene group is 60.)

  Moreover, it is preferable that this invention is a fullerene derivative which has a chemical structure represented by following formula (3).

（式（３）中、フラーレン基の炭素数は６０であり、ＮＴｆ₂ ^-はビス（トリフルオロメチルスルホニル）イミド）アニオン（ＴＦＳＩ）である。）

(In formula (3), the carbon number of the fullerene group is 60, and NTf ₂ ⁻ is a bis (trifluoromethylsulfonyl) imide) anion (TFSI). )

  Moreover, it is preferable that this invention is a fullerene derivative which has a chemical structure represented by following formula (4).

（式（４）中、フラーレン基の炭素数は６０であり、ＮＴｆ₂ ^-はビス（トリフルオロメチルスルホニル）イミド）アニオン（ＴＦＳＩ）である。）

(In the formula (4), the fullerene group has 60 carbon atoms, and NTf ₂ ⁻ is a bis (trifluoromethylsulfonyl) imide) anion (TFSI). )

  Moreover, it is preferable that this invention is a fullerene derivative which has a chemical structure represented by following formula (5).

（式（５）中、フラーレン基の炭素数は６０であり、ＮＴｆ₂ ^-はビス（トリフルオロメチルスルホニル）イミド）アニオン（ＴＦＳＩ）である。）

(In the formula (5), the number of carbon atoms of a fullerene group is 60, NTf ₂ ^- bis (trifluoromethyl) imide) is an anion (TFSI). )

  Moreover, it is preferable that this invention is a fullerene derivative which has a chemical structure represented by following formula (6).

（式（６）中、フラーレン基の炭素数は６０である。）

(In formula (6), the carbon number of the fullerene group is 60.)

  Among these fullerene derivatives of the present invention, the fullerene derivative having the chemical structure represented by the formula (2) is preferable because it has ferromagnetism.

In order to use fullerene (C ₆₀ , hereinafter simply referred to as C ₆₀ ) as a material for an electric device or a functional molecular material, it is necessary to bond a functional group to C ₆₀ . However, methods for synthesizing C ₆₀ derivatives and C ₆₀ groups are still not well understood. Fullerene is slightly soluble in benzene and chlorobenzene, but not in most organic solvents. On the other hand, the fullerene derivative according to the present invention in which a functional group having an ionic bond site is bonded to fullerene is dissolved in various organic solvents and has magnetism, so that the material for an electric device, the functional molecular material, It is an organic salt that can be applied as a solvent for various reactions.

<Fullerene>
The possibility of the stable existence of C ₆₀ and C ₇₀ carbon cluster molecules was first shown in 1985 by Kroto & Smalley. Subsequent detailed studies revealed the structure of this carbon cluster. This molecule is a molecule in which 60 or 70 carbon atoms are bonded in a spherical shape. These molecules have been named Fullerene after Buckminster Fuller, who created a dome architecture similar to this structure. In addition to C ₆₀ and C ₇₀ , C ₇₆ , C ₇₈ , C ₈₂ , C ₈₄ , C ₉₀ , C _{94 and the} like are known as fullerenes that have been clarified so far. These fullerenes are electrically insulating materials, but when doped with an alkali metal, the resistivity is reduced by 10 digits or more, which is very promising as a material for electric devices.

<Method for producing fullerene derivative according to the present invention>
The fullerene derivative according to the present invention is obtained by introducing a tertiary amine side chain from fullerene (C ₆₀ ) using a glycine derivative and an alkyl aldehyde having an appropriate chain length, for example, as a fullerene derivative precursor described in Examples below. The bodies 2a, 4a, 5a are manufactured. The fullerene (C ₆₀ ) is sold by, for example, Frontier Carbon Co., Ltd.

  The fullerene derivative having the chemical structure represented by the general formula (1) according to the present invention, for example, the fullerene derivative having the chemical structure represented by the formula (2) is a tertiary amine moiety contained in the fullerene derivative precursor. Can be prepared by quaternization with a suitable alkyl halide. Among the fullerene derivatives according to the present invention, the fullerene derivative having the chemical structure represented by the formula (2) has ferromagnetism, and therefore, electrical device materials, functional molecular materials, various reaction solvents, etc. As very promising. In addition, the fullerene derivative having the chemical structure represented by the above formulas (3), (4), and (5) is obtained from the fullerene derivative quaternized with an alkyl halide as in the above formula (2) from the target anion. It can manufacture by carrying out anion exchange using the salt which has, for example, lithium bis (trifluoromethylsulfonyl) imide.

  In general, having ferromagnetism means that each atom has a magnetic susceptibility and the directions thereof are aligned in the same direction. Ferromagnetic means stick to magnet. Similarly, in the present invention, “ferromagnetism” means that the magnetization directions are the same and strong magnetism is exhibited.

<1: Synthesis of fullerene derivative precursor>
Fullerene (C ₆₀ , manufactured by Frontier Carbon Co., Ltd., 1.00 g, 1.39 mmol), glycine derivative (492 mg, 2.78 mmol) represented by the following formula (7), and propionaldehyde (404 mg, 6.95 mmol) Was added to dry toluene (230 ml) and heated under reflux in an argon atmosphere for 4 h (4 hours), concentrated under reduced pressure to remove toluene, and then silica gel flash column chromatography (carbon disulfide-ethyl acetate = 10: 1 to 1). 1: 1), and fullerene derivative 2a (372 mg, 0.42 mmol, 30%), 4a (189 mg, 0.16 mmol, 12%) and 5a (200 mg, 0.16 mmol, 12%) and unreacted fullerene (421 mg) , 42%) was isolated and purified.

The obtained fullerene derivatives 2a, 4a and 5a were subjected to ionization mass spectrometry (TOFMS) as a physical property measurement. The spectrum data is shown below.
Fullerene derivative 2a: TOFMS (m / z) 892.52, 856.48, 825.61, 720.29, 700.44.
Fullerene derivative 4a: TOFMS (m / z) 1066.71, 923.19, 907.42, 892.31, 864.25.
Fullerene derivative 5a: TOFMS (m / z) 1241.87, 1067.65, 894.39, 825.48, 579.42.

<Example 1: Synthesis of fullerene derivative (1)>
Fullerene derivative 2a (600 mg, 0.671 mmol) was added to methyl iodide (8.0 ml), heated under reflux for 24 hours, concentrated under reduced pressure to remove excess methyl iodide, then washed with toluene (5 times), hexane After washing (once) and concentration under reduced pressure, a compound (363 mg, 0.350 mmol) having a chemical structure represented by the following formula (2) as a black powder was obtained in a yield of 52%.

  1 shows a TOFMS chart of a compound having a chemical structure represented by formula (2), and FIG. 2 shows an IR chart of a compound having a chemical structure represented by formula (2).

<Example 2: Synthesis of fullerene derivative (part 2: salt exchange reaction)>
Fullerene derivative (compound having the chemical structure represented by the above formula (2)) (363 mg, 0.350 mmol) and lithium bis (trifluoromethylsulfonyl) imide (100 mg, 0.350 mmol) in dry acetone (10 ml). In addition, the mixture was stirred at room temperature for 2 days. After removing the acetone by concentration under reduced pressure, washing with hexane (twice), followed by washing with deionized water (three times), a fullerene derivative (compound having a chemical structure represented by the following formula (3)) (363 mg, 0 .305 mmol) was obtained in a yield of 87%.

<Examples 3 and 4>
In the same manner as in Example 1, a fullerene derivative having a chemical structure represented by the following formula (6) was obtained from the fullerene derivative 4a (Example 3). Further, a compound compound having a chemical structure represented by the following formula (4) was obtained from the fullerene derivative of the formula (6) by the same salt exchange reaction as that in Example 2 (Example 4).

<Example 5>
A fullerene derivative was synthesized from the fullerene derivative 5a in the same manner as in Example 1 and Example 2, and a fullerene derivative having a chemical structure represented by the following formula (5) was obtained by a salt exchange reaction.

3 shows a TOFMS chart of the compound of the formula (3), and FIG. 4 shows an F ¹⁹ -NMR chart (489 MHz, CDCl ₃ ) of the compound of the formula (3).

<4: Magnetic susceptibility evaluation>
The above compound of formula (2) had a magnetic modulus of 3.8 BM (Bohr magneton) at room temperature.
The magnetic susceptibility was measured as follows. The apparatus used is an MPMS-5S SQUID magnetometer manufactured by Quantum Design. A sample of about 10 mg was put in a quartz cell and measured at a low temperature (10K). While maintaining the temperature constant, the magnetic field was changed from 0 → 50000 [Oe] → 0 [Oe] → −50000 [Oe] → 0 [Oe], and the magnetization curve was measured. It was converted per mole number.
FIG. 5 shows the temperature change of the magnetic susceptibility of the fullerene derivative thus obtained. In FIG. 5, H represents a magnetic field, T represents temperature, M represents magnetization, and the horizontal axis represents a value obtained by dividing the magnetic field (H) by the measured temperature (T) (this time measured by 10K), and the vertical axis represents This is a value obtained by dividing the magnetization (M) by the number of moles (mol) of the sample.
The magnetic susceptibility measurement was performed by Professor Mori of the Department of Chemistry, Faculty of Science, Kanagawa University, who is an expert in measuring the magnetic susceptibility of complex molecules.

<Magnetic susceptibility measurement results>
The fullerene derivative (compound of formula (2)) was found to exhibit ferromagnetism from the results of temperature change experiments. The compound of formula (2) is the first discovery example of a derivative exhibiting ferromagnetism among the fullerene derivatives.

<Comparative Example 1>
In the same manner as described above, the magnetic susceptibility of fullerene (C ₆₀ , Frontier Carbon Co., Ltd.) was measured and shown in FIG. FIG. 5 shows that fullerene is paramagnetic.

<Consideration of magnetic susceptibility measurement results>
The reason why ferromagnetism develops is unknown at present, but it is considered that about 3 spins per molecule are present in the fullerene derivative (compound of formula (2)).

  It has been known that fullerene itself has paramagnetism, but there has been no report on investigation of magnetic changes caused by derivatization of fullerene, and no report has been made on fullerene derivatives exhibiting ferromagnetism. The compound of the formula (2) of the present invention is a ferromagnetic material composed only of an organic substance containing no metal. That is, the fullerene derivative of the present invention is a magnetic material composed only of an organic substance that does not contain any metal. In particular, the compound of the formula (2) is a ferromagnetic substance, and is an organic salt that can be applied to electric device materials and functional molecular materials, and can be preferably applied to various reaction solvents.

The TOFMS chart of the fullerene derivative of Formula (2). IR chart of the fullerene derivative of formula (2). The TOFMS chart of the fullerene derivative of Formula (3). F ¹⁹ -NMR chart of the fullerene derivative of the formula _{(3) (489MHz, CDCl 3} ). The graph which shows the temperature change of the magnetic susceptibility of a fullerene derivative.

Claims (7)

A fullerene derivative having a chemical structure represented by the following general formula (1).

(In Formula (1), carbon number of a fullerene group is 60, x is an integer of 1-10, y is an integer of 1-20, z is an integer of 1-20, b is an integer of 1-20, c Represents an integer of 1-20.
R _A , R _B and R _C are monovalent groups selected from the group consisting of hydrogen, aliphatic hydrocarbon groups, aromatic hydrocarbon groups, carboxylic acid groups, ester groups, ether groups, acyl groups and amino groups. It may contain one or more types of chemical structures and may have branches or substituents.
L ⁻ is a counter ion (anion component), and I ⁻ , Br ⁻ , AlCl ₄ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , bis (trifluoromethylsulfonyl) imide anion, CHF ₂ —CF ₂ —CH ₂ OSO. ₃ ^- _{atomic, CHF 2 - (CF 2)} 3 -CH 2 OSO 3 - _{atomic, CF 3 - (CF 2)} 2 -CH 2 OSO 3 - atomic and _{CF 3 - (CF 2) 6} -CH 2 OSO ₃ ^- may comprise one or more atomic groups selected from the group consisting of atomic. ) The fullerene derivative which has a chemical structure represented by following formula (2).

(In Formula (2), the carbon number of the fullerene group is 60.) The fullerene derivative which has a chemical structure represented by following formula (3).

(In formula (3), the carbon number of the fullerene group is 60, and NTf ₂ ⁻ is a bis (trifluoromethylsulfonyl) imide) anion (TFSI). ) The fullerene derivative which has a chemical structure represented by following formula (4).

(In the formula (4), the fullerene group has 60 carbon atoms, and NTf ₂ ⁻ is a bis (trifluoromethylsulfonyl) imide) anion (TFSI). ) The fullerene derivative which has a chemical structure represented by following formula (5).

(In the formula (5), the number of carbon atoms of fullerene groups are at 60, NTf ₂ ^- bis (trifluoromethyl) imide) is an anion (TFSI). ) The fullerene derivative which has a chemical structure represented by following formula (6).

(In formula (6), the carbon number of the fullerene group is 60.) The fullerene derivative according to claim 2, which has ferromagnetism.

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