JP2002060211A - Method for producing hetero-fullerene part of carbon skeleton of which is substituted with boron and nitrogen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an industrially advantageous method for producing hetero- fullerene in higher yield by substituting part of the carbon skeleton with boron and nitrogen. SOLUTION: This hetero-fullerene producing method comprises reacting fullerene with boron nitride under irradiation with a laser beam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a heterofullerene in which a carbon skeleton is partially substituted with boron and nitrogen.

[0002]

2. Description of the Related Art Fullerene, which is the third carbon allotrope next to diamond and graphite, has been attracting attention in various fields because of its unique structure and properties since its mass synthesis was developed. Then, heterofullerene in which part of the carbon skeleton is substituted with boron, nitrogen, etc.
New physical and chemical properties such as superconductivity, ferromagnetism, corrosion resistance, ultra-hardness, and nonlinear characteristics are expected.

However, heretofore, there are very few specific examples of heterofullerenes in which a part of the carbon skeleton is substantially substituted with two elements of boron and nitrogen, and there are only a few specific examples of heterofullerenes proposed by the inventors. There is only JP-A-11-60222. The invention described in this publication discloses that the above heterofullerene is prepared by ablating boron and nitrogen-containing graphite under pulsed laser irradiation under an argon atmosphere, or by ablating boron-containing graphite under pulsed laser irradiation under a nitrogen atmosphere. To manufacture. " According to the present invention, it is possible to obtain a heterofullerene obtained by substituting two elements of boron and nitrogen. However, according to studies by the present inventors, the amount of the target heterofullerene to be produced is sufficient. However, it has been found that there are some problems in various applications using this device.

[0004]

The present invention has been made under the above circumstances, and further develops the invention described in JP-A-11-60222, in which a part of the carbon skeleton is substituted with boron and nitrogen. It is an object of the present invention to provide an industrially advantageous method for producing a heterofullerene which can obtain the obtained heterofullerene in a higher yield.

[0005]

Means for Solving the Problems The present inventors have selected fullerene and boron nitride as raw materials, and when these systems are irradiated with laser light, a part of the carbon skeleton is formed of boron and nitrogen in high yield. The inventors have found that a substituted heterofullerene can be obtained, and have completed the present invention. That is, according to the present invention, first, in producing a heterofullerene in which part of the carbon skeleton is substituted with boron and nitrogen, the fullerene is reacted with boron nitride under laser irradiation, A method for producing fullerene is provided. Secondly, there is provided a method for producing a heterofullerene, wherein the laser light is pulsed light in the first production method.

[0006] The fullerene which is a raw material of the present invention includes:
All conventionally known ones can be used. Such fullerenes, although C ₆₀ is of representative, not limited to this in the present invention, the number of carbon atoms, such as C ₇₀ can be used more than 60 fullerenes. A mixture of two or more of these may be used. These fullerenes are, as is well known, starting from a carbonaceous material.
It is synthesized by a laser vaporization method, an arc discharge method, a plasma discharge method, a combustion method, a discharge plasma method, or the like.

As the other raw material used in the present invention, boron nitride having a high purity is preferably used, but contains impurities such as iron, chromium, nickel and boron oxide as long as the reaction is not inhibited. Things can also be used.

[0008] The proportion of the fullerene and boron nitride used is appropriately determined according to the substitution rate of boron and nitrogen contained in the target heterofullerene. For example, when synthesizing a heterofullerene having a content ratio of boron and nitrogen to carbon of 1: 1: 58, the ratio of fullerene to boron nitride used is 1: 571.

In the present invention, these raw material systems are preferably dissolved or suspended / dispersed in a solvent in advance before laser irradiation. As such a solvent, for example, a wide range of organic solvents such as hexane and toluene can be used.

Next, in the present invention, a laser beam is irradiated to a raw material system composed of fullerene and boron nitride, preferably dissolved or suspended or dispersed in a solvent. The laser light may be continuous light or pulsed light, but it is preferable to use pulsed light from the viewpoint of high yield. Examples of such laser light include an excimer laser, a nitrogen laser, a Nd: YAG laser, and the like. Although light having a wide range of wavelengths can be used, ArF (193 nm) and KrF (2
48 nm), XeCl excimer laser (308 n)
m), the third harmonic (3
It is preferable to use a wavelength of 55 nm) or the fourth harmonic (266 nm).

Although the reaction temperature of the present invention is arbitrarily set,
Since the reaction between fullerene and boron nitride under light irradiation proceeds without heating, it is usually performed at room temperature.

The reaction of the present invention is preferably carried out in an atmosphere of an inert gas, and particularly preferably in an atmosphere of argon or nitrogen since it may proceed through a radical reaction.

[0013]

The present invention will be described in more detail with reference to the following examples.

[0014] hexane solution of Example ^{_{1 C 60 (2 × 10 -4}} mol / l, 7
ml) with boron nitride (0.8 mmol) to prepare a suspension. This suspension is put into a synthetic quartz reaction vessel, and is stirred under an argon atmosphere with a KrF excimer laser (248 nm, 1 Hz, 200 mJ / cm ² ).
Was irradiated at room temperature for 1 hour. Thereafter, the precipitate was removed, and the precipitate was subjected to pyridine extraction.
Separation and purification were performed using C, and FAB-MS measurement was performed. As shown in FIG. 1, generation of boron and nitrogen-substituted fullerene BNC ₅₈ was confirmed at a mass number of 721. Yield 30%.

The hexane solution (2 × ¹⁰ Example _{2 C 70 -4 mol / l,} 7
ml) with boron nitride (0.8 mmol) to prepare a suspension. This suspension is put into a synthetic quartz reaction vessel, and is stirred under an argon atmosphere with a KrF excimer laser (248 nm, 1 Hz, 200 mJ / cm ² ).
Was irradiated at room temperature for 1 hour. Thereafter, the precipitate was removed, and the precipitate was extracted with pyridine.
Separation and purification were performed by LC, and FAB-MS measurement was performed. The formation of boron and nitrogen-substituted fullerene BNC _{68 at} a mass number of 841 was confirmed.

[0016]

As described above, according to the present invention,
By performing the reaction of fullerene and boron nitride under laser irradiation, it is possible to produce a heterofullerene in which part of the carbon skeleton has been replaced by two types of elements, boron and nitrogen, which has been difficult to synthesize in the past. Become.

[Brief description of the drawings]

[1] _{C 60} and under an argon atmosphere hexane suspension of boron nitride, KrF excimer laser at room temperature (24
8 nm) is a mass spectrum of the product when irradiated.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tsuguori Ohana 1-1-1, Higashi, Tsukuba, Ibaraki Pref., National Institute of Advanced Industrial Science and Technology (72) Inventor Masanori Ishihara 1-1-1, Higashi, Tsukuba, Ibaraki Industrial Technology (72) Inventor Shuzo Fujiwara 1-1 1-1 Higashi, Tsukuba City, Ibaraki Pref. F-term (Reference) 4M046 CB01 CC03

Claims (2)

[Claims] 1. A method for producing a heterofullerene, which comprises reacting fullerene and boron nitride under laser irradiation to produce a heterofullerene in which part of the carbon skeleton is substituted with boron and nitrogen. 2. The method according to claim 1, wherein the laser light is pulsed light.