JP2020138945A - Cyclacene precursor and method for producing the same, and heterocyclacene precursor and method for producing the same - Google Patents

Abstract

To provide a compound that is useful for the synthesis of a zigzag type carbon nanotube.SOLUTION: The present invention is a cyclacene precursor, in which, when certain one benzene ring of a cyclacene, in which 2(m+n) benzene rings (m and n are each an integer of 2 or more) are cyclically condensed, is designated as a 1st benzene ring and numbering is done in order from there, the 1st benzene ring, the (m+1)th benzene ring, the (m+n+1)th benzene ring, and the (2 m+n+1)th benzene ring have a bridge structure represented by the following formula (1) or (2) between the 1st position and the 4th position in each benzene ring.SELECTED DRAWING: None

Description

The present invention relates to template materials used in the production of carbon nanotubes.

Carbon nanotubes (hereinafter referred to as "CNT") are excellent in electron transport characteristics, thermal conductivity, etc., and have high mechanical strength and are lightweight. Therefore, various technologies such as electronic device materials, heat dissipation materials, and high-strength composite materials are used. It is expected to be applied in the field. The CNT has a structure in which a graphene sheet is wound into a tubular shape, and is classified into an armchair type, a spiral type, and a zigzag type according to the winding method (chirality) of the graphene sheet. The carbon nanotubes include single-walled carbon tubes (SWNTs) and multi-walled carbon nanotubes (MWNTs) in which SWNTs are nested. Unless otherwise specified, SWNTs are referred to as CNTs in the present specification.

CNTs have metallic or semiconductor properties depending on how they are wound, armchair-type CNTs exhibit metallic properties, and spiral-type and zigzag-type CNTs exhibit metallic properties or semiconductor properties. Whether the spiral CNT or the zigzag CNT exhibits the properties of a metal or a semiconductor is determined by the chiral index (a, b) (an index indicating chirality) and the diameter of the CNT. Since the properties required for CNTs differ depending on the application, a technique for selectively synthesizing CNTs having a specific structure and a uniform diameter is required.

However, it is impossible to control the structure and diameter of CNTs in any of the conventional general methods for synthesizing CNTs, such as the laser evaporation method, the arc discharge method, and the chemical vapor deposition method (CVD method). , Various structures and various diameters of CNTs are mixed and synthesized. Therefore, it is necessary to separate CNTs having an appropriate structure and diameter for each application.

On the other hand, it has been suggested that by using an organic compound having a cyclic structure as a template for CNT synthesis, it is possible to synthesize CNTs having a specific structure and having a uniform diameter (Non-Patent Document 1). By now, cyclic organic compounds (eg, cycloparaphenylene, carbon nanobelts) that can serve as templates for armchair-type CNTs and spiral-type CNTs have been synthesized. On the other hand, no cyclic organic compound that can serve as a template for zigzag CNTs has been found.

Omachi, H .; Nakayama, T .; Takahashi, E .; Segawa, Y .; Itami, K., Nature Chemistry, 2013, 5, 572. Urgel, J .; Mishra, S .; Hayashi, H .; Wilhelm, J .; Pignedoli, CA; Giovannantonio, MD; Widmer, R .; Yamashita, M .; Hieda, N .; Ruffieux, P .; Yamada, H .; Fasel, R. Nature Communication, 2019, 10, 861. Tanaka, K .; Aratani, N .; Kuzuhara, D .; Sakamoto, S .; Okujima, T .; Ono, N .; Uno, H .; Yamada, H. RSC Advances, 2013, 3, 15310-15315. Yamada, H .; Yamashita, Y .; Kikuchi, M .; Watanabe, H .; Okujima, T .; Uno, H .; Ogawa, T .; Ohara, K .; Ono, N., Chemistry − A European Journal , 2005, 6212. Hasegawa, K .; Noda, S., ACS Nano, 2011, 5, 975.

An object to be solved by the present invention is to provide a compound useful for the synthesis of zigzag carbon nanotubes.

Although the cyclacene skeleton is promising as a template for zigzag carbon nanotubes, a method for synthesizing cyclacene has not been established. In addition, cyclacene is highly reactive with oxygen, so even if it is synthesized, it decomposes immediately (that is, it is a compound with an unstable structure). Therefore, the present inventor has arrived at the present invention with the idea of synthesizing a cyclacene precursor which is excellent in structural stability and can be easily converted into cyclacene.

That is, the present invention made to solve the above problems is
When one benzene ring of cyclacene in which 2 (m + n) benzene rings (m and n are integers of 2 or more each) are cyclically condensed as the first benzene ring and numbered in order from there, The 1st benzene ring, the (m + 1) th benzene ring, the (m + n + 1) th benzene ring, and the (2m + n + 1) th benzene ring are placed between the 1st and 4th positions in each benzene ring according to the following formula (1) or It is a cyclacene precursor having a crosslinked structure represented by (2).

In the cyclacene precursor, the 1st and 4th positions having a crosslinked structure are the 1st benzene ring, the (m + 1) th benzene ring, the (m + n + 1) th benzene ring, and the (2m + n + 1) th benzene ring. Refers to the position inside each benzene ring, and does not indicate the position of the cyclacene precursor as a whole.

The cyclacene precursor according to the present invention has an excellent stability under normal conditions because the benzene ring at a predetermined position has a crosslinked structure represented by the formula (1) or (2). Moreover, the crosslinked structure is removed from the benzene ring by irradiating or heating with light, and the cyclacene precursor is converted to cyclacene, so that cyclacene can be easily obtained. When the crosslinked structure is removed from the cyclacene precursor and converted to cyclacene in the carbon nanotube synthesis system, the obtained cyclacene is used as seeds and extends in both sides to grow into zigzag carbon nanotubes, as shown below. Cyclacene from which the crosslinked structure has been removed is unstable, but by performing a series of synthesis in the carbon nanotube synthesis system in this way, carbon nanotubes grown in the bilateral directions can be formed using cyclacene as seeds.

In this case, by increasing the number of benzene rings constituting the cyclacene precursor (that is, increasing the number of m and n), carbon nanotubes having a large diameter can be obtained. In addition, long carbon nanotubes can be obtained by lengthening the reaction time (light irradiation time or heating time) for conversion to cyclacene, or by increasing the carbon source such as ethanol introduced in the carbon nanotube manufacturing process. That is, by using the cyclacene precursor according to the present invention, it is possible to synthesize zigzag carbon nanotubes having an appropriate diameter and length.

Examples of the cyclacene precursor whose crosslinked structure is represented by the above formula (1) include a structure represented by the following formula (5) or formula (6).

Formula (5) is an example of the case where 2 (m + n) "m" and "n", which are the number of condensed benzene rings, are different (m = 4, n = 3), and formula (6) is " This is an example of the case where "m" and "n" are equal (m = n = 4).

Further, as an example of the cyclacene precursor whose crosslinked structure is represented by the above formula (2), a structure represented by the following formula (7) can be mentioned.
Equation (7) is an example of the case where 2 (m + n) "m" and "n", which are the number of condensed benzene rings, are equal (m = n = 4). Although not shown here, even in the cyclacene precursor whose crosslinked structure is represented by the above formula (2), naturally, "m" and "n" may have different structures.

Carbon nanotubes having different diameters can be synthesized by changing the numbers of m and n, but when the number of m and n is large, it becomes difficult to synthesize a cyclacene precursor. In terms of ease of synthesis, m = n = 2 (ie, the number of benzene rings is 8), m = 4, n = 3 (ie, the number of benzene rings is 14), m = n = 4 (ie, the number of benzene rings). It is preferable that the number of benzene rings is 16) and m = n = 5 (that is, the number of benzene rings is 20).

Another aspect of the present invention is a method for producing cyclacene.
The process of preparing the cyclacene precursor and
The cyclacene precursor is provided with a step of irradiating the cyclacene precursor with light or heating the cyclacene precursor to convert the cyclacene precursor into cyclacene.
One benzene ring of cyclacene in which 2 (m + n) benzene rings (m and n are integers of 2 or more each) are cyclically condensed as the cyclacene precursor is used as the first benzene ring, and the benzene rings are sequentially condensed from there. When numbered, the 1st benzene ring, the (m + 1) th benzene ring, the (m + n + 1) th benzene ring, and the (2m + n + 1) th benzene ring are either of the following formula (1) or the following (2). It is characterized by having a crosslinked structure shown in 1.

It is known that when a compound having a crosslinked structure represented by the above formulas (1) and (2) is irradiated with light or heated, the crosslinked structure is removed (see, for example, Non-Patent Documents 3 and 4). From this, when the cyclacene precursor having the crosslinked structure represented by the formula (1) or (2) is irradiated with light or the cyclacene precursor is heated, the cyclacene precursor is converted into cyclacene. it is obvious.

Yet another aspect of the present invention is a method for producing zigzag carbon nanotubes.
The process of preparing the cyclacene precursor and
A carbon nanotube synthetic system comprising a step of irradiating the cyclacene precursor with light or heating the cyclacene precursor to convert the cyclacene precursor into cyclacene.
One benzene ring of cyclacene in which 2 (m + n) benzene rings (m and n are integers of 2 or more each) are cyclically condensed as the cyclacene precursor is used as the first benzene ring, and the benzene rings are sequentially condensed from there. When numbered, the 1st benzene ring, the (m + 1) th benzene ring, the (m + n + 1) th benzene ring, and the (2m + n + 1) th benzene ring are either of the following formula (1) or the following (2). It is characterized by having a crosslinked structure shown in 1.

In the above method for producing carbon nanotubes, by prolonging the time for irradiating the cyclacene precursor with light or the time for heating the cyclacene precursor, many cyclacene precursors can be converted into cyclacene, or a carbon source such as ethanol can be used. A longer carbon nanotube can be obtained by introducing more carbon nanotubes into the carbon nanotube manufacturing process (Non-Patent Document 5). The carbon nanotube synthesis system in the above production method can be constructed with reference to, for example, the description in Non-Patent Document 1.

In addition, the present invention made to solve the above problems
It is a heterocyclacene precursor having a structure in which a plurality of structural units represented by the following formula (3) or the following formula (4) are connected in a ring shape.

The heterocyclacen precursor is converted to heterocyclacene by irradiation with light or heating.
Therefore, another aspect of the present invention is
The process of preparing the heterocyclacene precursor and
A step of converting the heterocyclacen precursor into heterocyclase by irradiating the heterocyclacen precursor with light or heating the heterocyclacene precursor is provided.
This is a method for producing a heterocyclacen, wherein the heterocyclacen precursor has a structure in which a plurality of structural units represented by the following formula (3) or the following formula (4) are connected in a ring shape.

Further, if the conversion from the heterocyclacen precursor to the heterocyclacene is carried out by a carbon nanotube synthetic system, as shown below, the heterocyclacene converted from the heterocyclacene precursor is used as seeds and extends in both sides. It can be grown into carbon nanotubes.

Therefore, yet another aspect of the present invention is
The process of preparing the heterocyclacene precursor and
A carbon nanotube synthesis system comprising a step of converting the heterocyclacen precursor into heterocyclacene by irradiating the heterocyclacene precursor with light or heating the heterocyclacene precursor.
This is a method for producing a zigzag carbon nanotube, wherein the heterocyclacene precursor has a structure in which a plurality of structural units represented by the following formula (3) or the following formula (4) are connected in a ring shape.

Since the heterocyclacene precursor has a structure containing nitrogen, a nitrogen-doped zigzag carbon nanotube can be obtained by using the heterocyclacene precursor as a material for carbon nanotubes.

In the heterocyclacen precursor, the heterocyclacen production method, and the zigzag carbon nanotube production method, the heterocyclacene precursor has two structural units represented by the formula (3) or the formula (4). Alternatively, it is preferable to have a structure in which three or four pieces are connected in an annular shape. Heterocyclacene precursors of these structures can be synthesized relatively easily.
For example, the following formula (8) is an example of a heterocyclacene precursor having a structure in which two structural units represented by the above formula (3) are connected in a ring shape.

The cyclacene precursor and the heterocyclacene precursor according to the present invention are stable under normal conditions. Therefore, by using these precursors, zigzag carbon nanotubes can be stably produced. Further, by adjusting the number of benzene rings and benzene ring derivatives constituting the cyclacene precursor and the heterocyclacene precursor, and by controlling the reaction time, zigzag carbon nanotubes having an appropriate diameter and length can be obtained. Can be manufactured.

The figure which shows the structure of an armchair type, a spiral type, and a zigzag type carbon nanotube. FIG. 3 is a manufacturing process diagram of a cyclacene precursor according to the first embodiment of the present invention. Mass spectrum of compound 8. FIG. 3 is a manufacturing process diagram of a heterocyclacen precursor according to a second embodiment of the present invention. Mass spectrum of compound [3 + 3]. Mass spectrum showing that compounds [2 + 2], [3 + 3], [4 + 4] were produced.

Hereinafter, specific examples of the cyclacene precursor and the method for producing the same according to the present invention will be described in detail with reference to the drawings. As the reagents and solvents used for the synthesis in the examples shown below, commercially available products were used as they were, or those purified by distillation in the presence of a desiccant were used.

<Example 1>
In this example, the cyclacene precursor represented by the symbol 8 in FIG. 2 was prepared. Incidentally, in this example, ^{1 H} nuclear magnetic resonance spectroscopy is measured by using JEOL Ltd. JNM-ECX400P, a JNM-ECX500 and JNM-ECA600, using tetramethylsilane (TMS) as internal standard. In addition, mass spectrometry was performed using a matrix-assisted laser desorption / ionization time-of-flight mass spectrometer (AutoflexII) manufactured by Bruker Japan Co., Ltd.

[Formation of compound 2 = process a]
The compound represented by the symbol 1 in FIG. 2 (hereinafter, referred to as compound 1 and the same applies to the compounds represented by other symbols) was synthesized by the method described in Non-Patent Document 2. Subsequently, potassium tert-butoxide (5.0 g, 44.6 mmol) was slowly added to a solution of compound 1 (4.5 g, 15 mmol) in tetrahydrofuran (150 ml) under an argon atmosphere, and the mixture was stirred at 50 ° C. for 2 hours. After cooling to room temperature, the reaction was stopped with water, and the reaction solvent was distilled under reduced pressure. A 2 M hydrochloric acid solution was added to the obtained residue, and the compound was extracted with dichloromethane. The organic layer was washed with water and saturated brine, dried over sodium sulfate, and the solvent was evaporated under reduced pressure. The obtained residue was subjected to column chromatographic fluffy (hexane: dichloromethane = 9: 1, R _f = 0.38) to isolate the oily target product in a yield of 99% (3.4 g).

For the desired ^product, a ¹ H nuclear magnetic resonance spectroscopy ⁽¹ H NMR) As a result of structural analysis by below.
¹ H NMR (400 MHz, CDCl ₃ ): δ 6.43 (m, 1H), 6.24 (m, 1H), 5.39 (s, 1H), 5.25 (s, 1H), 4.89 (s, 1H), 3.57 (dd , 1H), 3.40-3.26 (m, 5H), 1.67 (m, 1H), 1.52 (m, 1H) ppm.
From the above results, it was confirmed that the target product was compound 2 in FIG.

[Formation of compound 3 = process b]
N-butyl diluted in toluene (150 ml) with respect to a toluene solution (770 ml) of compound 2 (5.3 g, 23.0 mmol) and 1,2,4,5-tetrabromobenzene (4.5 g, 11.5 mmol). A lithium hexane solution (22.5 ml, 1.6 M in hexane, 34.5 mmol) was slowly added under an argon atmosphere at -18 ° C. over 3 hours. Then, after stirring at -18 ° C. for 1 hour, the reaction solution was gradually returned to room temperature and stirred overnight. Next, the reaction was stopped with methanol, and the organic solvent was distilled off under reduced pressure. The obtained residue was subjected to column chromatographic fluffy (methylene chloride: hexane = 1: 2, R _f = 0.38) to obtain the desired product in a yield of 43% (2.6 g).

For the desired ^product, a ¹ H nuclear magnetic resonance spectroscopy ⁽¹ H NMR) As a result of structural analysis by below.
^{1 1} H NMR (400 MHz, CDCl ₃ ): δ 6.93 (q, 2H), 6.59-6.56 (m, 2H), 6.36 (t, 2H), 3.84-3.03 (m, 20H), 1.74-1.46 (m, 4H) ppm.
From the above results, it was confirmed that the target product was compound 3 in FIG.

[Formation of compound 4 = process c]
Compound 3 (5.0 g, 9.4 mmol) and 2,3-dichloro-5,6-dicyano-p-benzoquinone (5.0 g, 22.0 mmol) were added to chloroform (1.5 L) under an argon atmosphere, and the mixture was added at 50 ° C. for 12 hours. Stirred. Then, the reaction solution was returned to room temperature, and a sodium hydrogen carbonate solution was added. The organic layer was washed with water and saturated brine, dried over sodium sulfate, and evaporated under reduced pressure. The obtained residue was subjected to column chromatographic fluffy (chloroform, R _f = 0.85) to obtain the desired product in a yield of 73% (3.6 g).

For the desired ^product, a ¹ H nuclear magnetic resonance spectroscopy ⁽¹ H NMR) As a result of structural analysis by below.
^{1 1} H NMR (500 MHz, CDCl ₃ ): δ 8.26 (t, 2H), 7.76 (dd, 4H), 6.73 (m, 2H), 6.54 (m, 4H), 4.16 (m, 4H), 3.55-2.87 (m, 8H), 1.84-1.79 (m, 2H), 1.70-1.67 (m, 2H) ppm. ¹³ C NMR (CDCl ₃ ): δ 140.05, 136.99, 136.13, 133.10, 130.79, 130.52, 125.34, 122.97, 120.81, 48.41, 48.32, 47.65, 46.71, 42.51, 42.20 ppm.
From the above results, it was confirmed that the target product was compound 4 in FIG.

[Formation of compound 5 = process d]
Compound 4 (570 mg, 1.1 mmol) was added to tetrahydrofuran (170 ml) under an argon atmosphere, and potassium tert-butoxide (1.5 g, 13.4 mmol) was added slowly. Then, the reaction solution was stirred with heating under reflux for 20 hours. After cooling to room temperature, water was added to stop the reaction, and the solvent was distilled off under reduced pressure. Dichloromethane was added to dissolve the residue, which was washed with a 2 M hydrochloric acid solution, further washed with water and saturated brine, dried over sodium sulfate, and the organic solvent was evaporated under reduced pressure. The obtained residue was subjected to column chromatographic fluffy (chloroform: hexane = 2: 1, R _f = 0.33) to obtain the desired product in a yield of 78% (330 mg).

For the desired ^product, a ¹ H nuclear magnetic resonance spectroscopy ⁽¹ H NMR) As a result of structural analysis by below.
^{1 1} H NMR (500 MHz, CDCl ₃ ): δ 8.20 (s, 2H), 7.72 (s, 4H), 6.68-6.66 (m, 4H), 5.3 (d, 4H), 5.08 (d, 4H), 4.59 (t, 4H) ppm. ¹³ C NMR (CDCl3): δ = 143.98, 139.00, 134.47, 130.83, 125.25, 120.42, 104.74 ppm.
From the above results, it was confirmed that the target product was compound 5 in FIG.

[Formation of compound 6 = process e]
N-butyllithium diluted in toluene (80 ml) with respect to a toluene solution (410 ml) of compound 5 (500 mg, 1.6 mmol) and 1,2,4,5-tetrabromobenzene (610 mg, 1.6 mmol) A hexane solution (6.2 ml, 1.6. M in hexane, 9.2 mmol) was slowly added under an argon atmosphere at -5 ° C for 50 minutes. Then, after stirring at -5 ° C. for 1 hour, the reaction solution was gradually returned to room temperature and stirred overnight. Next, the reaction was stopped with methanol, and the organic solvent was distilled off under reduced pressure. The obtained residue was reprecipitated with chloroform and hexane to give the desired product in a yield of 55% (390 mg, 0.43 mmol).

For the compound is shown ^{1 H-nuclear} magnetic resonance spectroscopy ^{(1 H} NMR) results subjected to structural analysis by and the results of mass spectrum below.
^{1 1} H NMR (500 MHz, CDCl ₃ ): δ 7.98 (m, br, 4H), 7.54 (m, br, 8H), 6.87 (m, br, 12H), 4.62 (m, br, 8H), 3.54 ( m, br, 16H) ppm.
HR-MS (SPIRAL-TOF): calcd. For C ₇₂ H ₄₈ , 912.3751 [M] ⁺ ; found, 912.3745.
From the above results, it was confirmed that the target product was compound 6 in FIG.

[Formation of compound 7 = process f]
Compound 6 (150 mg, 0.16 mmol) and 2,3-dichloro-5,6-dicyano-p-benzoquinone (300 mg, 1.32 mmol) were added to chloroform (40 ml) under an argon atmosphere, and the mixture was added at 50 ° C. for 12 hours. Stirred. Then, the reaction solution was returned to room temperature, a sodium hydrogen carbonate solution was added, the organic layer was washed with water and saturated brine, dried over sodium sulfate, and evaporated under reduced pressure. The obtained residue was subjected to column chromatographic fluffy (chloroform, Rf = 0.85) to obtain the desired product in a yield of 56% (81 mg).

For the desired product, a ^{1 H} nuclear magnetic resonance spectroscopy ^{(1 H} NMR) results of results and mass spectrometry was subjected to structural analysis by below. Mass spectrometry was performed using a matrix-assisted laser desorption / ionization time-of-flight mass spectrometer (AutoflexII) manufactured by Bruker Japan Co., Ltd.
^{1 1} H NMR (500 MHz, CDCl ₃ ): δ 8.10 (m, br, 8H), 7.77 (m, br, 16H), 7.02 (m, br, 8H), 5.26 (m, br, 8H) ppm.
HR-MS: calcd. For C ₇₂ H ₄₀ , 904.3125 [M] ⁺ ; found, 904.3117.
From the above results, it was confirmed that the target product was compound 7 of FIG.

[Formation of compound 8 = process g]
Palladium on carbon (Pd 10%, 3.5 mg) was added to a tetrahydrofuran solution (16 ml) of compound 7 (10 mg, 0.011 mmol), and hydrogen bubbling was performed. Then, the mixture was stirred at room temperature for 4 hours under a hydrogen atmosphere. Pd / C was removed by filtration, and the solvent was distilled off under reduced pressure to obtain the desired product in a yield of 25% (2.5 mg).
The results of mass spectrometry on the target product are shown below and in FIG. Mass spectrometry was performed using a matrix-assisted laser desorption / ionization time-of-flight mass spectrometer (AutoflexII) manufactured by Bruker Japan Co., Ltd.
MALDI-TOF Mass: 913.1981.
From the above results, it was confirmed that the target substance was the cyclacene precursor which is the compound 8 of FIG.

<Example 2>
In this example, a cyclacene precursor represented by the symbols [2 + 2], [3 + 3], and [4 + 4] in FIG. 4 was prepared. Incidentally, in this example, ^{1 H} nuclear magnetic resonance spectroscopy is measured by using JEOL Ltd. JNM-ECX400P, a JNM-ECX500 and JNM-ECA600, using tetramethylsilane (TMS) as internal standard. In addition, mass spectrometry was performed using a matrix-assisted laser desorption / ionization time-of-flight mass spectrometer (AutoflexII) manufactured by Bruker Japan Co., Ltd.

[Formation of compound 10 = process a]
Compound 9 was synthesized by the method described in Non-Patent Document 3. Subsequently, lithium aluminum hydride (545 mg, 14.3 mmol) was slowly added to Compound 9 (506 mg, 1.39 mmol) suspended in tetrahydrofuran (50 ml) under an argon atmosphere under an ice bath. Then, the reaction solution was stirred with heating under reflux for 1 hour. After cooling to 0 ° C. under an ice bath, a 6 M hydrochloric acid solution (35 ml) was slowly added, and then the reaction solution was stirred with heating under reflux for 1 hour. After cooling to room temperature, the resulting precipitate was filtered and the solid was washed with water and methanol. The resulting solid was then suspended in tetrahydrofuran (50 ml) under an argon atmosphere and lithium aluminum hydride (545 mg, 14.3 mmol) was slowly added under an ice bath. Then, the reaction solution was stirred with heating under reflux for 1 hour. After cooling to 0 ° C. under an ice bath, a 6 M hydrochloric acid solution (35 ml) was slowly added, and then the reaction solution was stirred with heating under reflux for 1 hour. After cooling to room temperature, the resulting precipitate was filtered and the solid was washed with water and methanol. The residue was purified by performing column chromatographic fluffy (chloroform: hexane = 1: 1, R _f = 0.8) to obtain the desired product in a yield of 39% (180 mg).

For the desired product, a ^{1 H} nuclear magnetic resonance spectroscopy ^{(1 H} NMR) result of the results was performed The results were subjected to structural analysis and mass spectrometry and mass spectrometry by below.
^{1 1} H-NMR (400 MHz, CDCl ₃ ): 8.20 (s, 2H), 7.64 (s, 4H), 6.56-6.58 (m, 4H), 4.00 (s, 4H), 1.62-1.67 (m, 8H) ..
HR-MS: calcd for C ₂₆ H ₂₂ , 334.1716 [M] ⁺ ; found, 334.1717.

[Formation of compound 11 = process b]
Compound 10 (229 mg, 0.686 mmol) suspended in acetone (250 mL) with N-methylmorpholin-N-oxide (0.793 g, 6.77 mmol) and microencapsulated osmium oxide (VIII) (10% microcapsule, 210) mg, 0.826 mmol) was added and reacted at room temperature for 4 days. Then, a saturated aqueous sodium dithionite solution (50 ml) was added to stop the reaction, and the mixture was stirred for 10 minutes. After distilling off the solvent under reduced pressure, water and ethyl acetate were added. After separating the organic layer, the organic layer was washed with saturated brine and dried over sodium sulfate. After distilling off the solvent under reduced pressure, the obtained residue was dispersed in chloroform, and the obtained precipitate was filtered and washed with methanol to obtain the desired product in a yield of 40% (143 mg).

For the desired product, a ^{1 H} nuclear magnetic resonance spectroscopy ^{(1 H} NMR) result of the results was performed The results were subjected to structural analysis and mass spectrometry and mass spectrometry by below.
^{1 1} H-NMR (400 MHz, CDCl ₃ ): 8.34 (s, 2H), 7.68 (s, 4H), 4.40 (s, br, 4H), 4.00 (s, 4H), 3.05 (s, 4H), 1.76 -1.77 (m, 4H), 1.36-1.40 (m, 4H).
HR-MS: calcd for C ₂₆ H ₂₆ O ₄ , 402.1826 [M] ⁺ ; found, 402.1829.

[Formation of compound 12 = process c]
Under an argon atmosphere, trifluoroacetic anhydride (1.4 ml, 10.0 mmol) was added dropwise at -80 ° C to a mixed solution of dimethyl sulfoxide (1.4 ml, 20 mmol) and methylene chloride (70 ml) over 20 minutes. After 1 hour from the completion of the dropwise addition, compound 11 (134 mg, 0.333 mmol) dissolved in a mixed solvent of dimethyl sulfoxide (7 ml) and methylene chloride (45 ml) was added dropwise over 3 hours. Then, the mixture was stirred at -80 ° C for 2 hours, diisopropylethylamine (3.5 ml, 20 mmol) was added dropwise over 5 minutes to stop the reaction, and the mixture was further stirred at -80 ° C for 1 hour. After returning the reaction solution to room temperature, the mixture was further stirred for 1 hour, a 3 M hydrochloric acid solution was added to the reaction solution, and then extraction was performed with dichloromethane. After separating the organic layer, the organic layer was washed with water and saturated brine, and dried over sodium sulfate. After distilling off the solvent under reduced pressure, the obtained residue was reprecipitated with dichloromethane and hexane to isolate the desired product in a yield of 89% (117 mg).

For the desired product, a ^{1 H} nuclear magnetic resonance spectroscopy ^{(1 H} NMR) result of the results was performed The results were subjected to structural analysis and mass spectrometry and mass spectrometry by below.
^{1 1} H-NMR (400 MHz, CDCl ₃ ): 8.42 (s, 2H), 7.91 (s, 4H), 4.18 (s, 4H), 2.38-2.40 (m, 4H), 2.16-2.17 (m, 4H) ..
HR-MS: calcd for C ₂₆ H ₁₈ O ₄ Na, 417.1097 [M + Na] ⁺ ; found, 417.1095.

[Formation of compounds [2 + 2], [3 + 3], [4 + 4] = process d]
Compound 11 (30 mg, 0.0761 mmol) and 1,2,4,5-benzenetetraamine-4 hydrochloride (22 mg, 0.0761) in a mixed solution of ethanol (18 ml) and acetic acid (30 ml) under an argon atmosphere. mmol) was added, and the mixture was stirred for 4 hours while heating at 100 ° C. Then, triethylamine (1.5 ml) was added, and the mixture was stirred at 130 ° C. for 18 hours. After cooling to room temperature, the obtained precipitate was filtered and the solid was washed with methanol to obtain 80% (35 mg) of compound [3 + 3] and a small amount of compound [2 + 2] and a small amount of compound [4 + 4].

Compounds for [2 + 2], the ^{1 H} nuclear magnetic resonance spectroscopy ^{(1 H} NMR) results of results and mass spectrometry was subjected to structural analysis by below.
^{1 1} H-NMR (400 MHz, CDCl ₃ ) for [3 + 3]: 8.67 (s, br, 6H), 8.28 (s, br 6H), 7.92 (s, br, 12H), 4.77 (s, br, 12H), 2.19 (s, br, 24H).
HR-MS (SPIRAL-TOF) for [3 + 3]: calcd for C ₉₆ H ₆₀ N ₁₂ , 1380.5058 [M ⁺ ]; found, 1380.5058.

FIG. 5 is a mass spectrum showing the results of mass spectrometry of the target product (compound [2 + 2], [3 + 3], [4 + 4]). From FIG. 5, it was confirmed that the compounds [2 + 2], [3 + 3], and [4 + 4] were produced. Further, FIG. 6 is an HR-MS mass spectrum of compound [3 + 3].

Claims (9)

When one benzene ring of cyclacene in which 2 (m + n) benzene rings (m and n are integers of 2 or more each) are cyclically condensed as the first benzene ring and numbered in order from there, The 1st benzene ring, the (m + 1) th benzene ring, the (m + n + 1) th benzene ring, and the (2m + n + 1) th benzene ring are placed between the 1st and 4th positions in each benzene ring by the following formula (1). Alternatively, a cyclacene precursor having a crosslinked structure represented by (2).
The process of preparing the cyclacene precursor and
The cyclacene precursor is provided with a step of irradiating the cyclacene precursor with light or heating the cyclacene precursor to convert the cyclacene precursor into cyclacene.
One benzene ring of cyclacene obtained by cyclically condensing 2 (m + n) benzene rings (m and n are integers of 2 or more each) of the cyclacene precursor as the first benzene ring, and in order from there. When numbered, the 1st benzene ring, the (m + 1) th benzene ring, the (m + n + 1) th benzene ring, and the (2m + n + 1) th benzene ring are either of the following formula (1) or the following (2). A method for producing cyclacene, which has a crosslinked structure shown in 1.
The process of preparing the cyclacene precursor and
A carbon nanotube synthetic system comprising a step of irradiating the cyclacene precursor with light or heating the cyclacene precursor to convert the cyclacene precursor into cyclacene.
One benzene ring of cyclacene obtained by cyclically condensing 2 (m + n) benzene rings (m and n are integers of 2 or more each) of the cyclacene precursor as the first benzene ring, and in order from there. When numbered, the 1st benzene ring, the (m + 1) th benzene ring, the (m + n + 1) th benzene ring, and the (2m + n + 1) th benzene ring are either of the following formula (1) or the following (2). A method for producing a zigzag carbon nanotube having a crosslinked structure shown in 1.
A heterocyclacene precursor having a structure in which a plurality of structural units represented by the following formula (3) or the following formula (4) are connected in a ring shape.
The heterocyclacene precursor according to claim 4, wherein the structural unit represented by the formula (3) or the formula (4) has a structure in which two, three or four structural units are connected in a ring shape. The process of preparing the heterocyclacene precursor and
A step of converting the heterocyclacen precursor into heterocyclase by irradiating the heterocyclacen precursor with light or heating the heterocyclacene precursor is provided.
A method for producing a heterocyclacen, wherein the heterocyclacen precursor has a structure in which a plurality of structural units represented by the following formula (3) or the following formula (4) are connected in a ring shape.
The method for producing heterocyclacen according to claim 7, wherein the structural unit represented by the formula (3) or the formula (4) has a structure in which two, three or four structural units are connected in a ring shape. The process of preparing the heterocyclacene precursor and
A carbon nanotube synthesis system comprising a step of converting the heterocyclacen precursor into heterocyclacene by irradiating the heterocyclacene precursor with light or heating the heterocyclacene precursor.
A method for producing a zigzag carbon nanotube, wherein the heterocyclacene precursor has a structure in which a plurality of structural units represented by the following formula (3) or the following formula (4) are connected in a ring shape.
The method for producing a zigzag-type carbon nanotube according to claim 8, wherein the structural unit represented by the formula (3) or the formula (4) has two, three, or four structural units connected in a ring shape.