JP2012250931A - Pentacene multimer, and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a quaternary or higher pentacene multimer, and a method for producing the pentacene multimer capable of producing the same.SOLUTION: Pentacene is used as a raw material, and the raw material is heated in a sealed container to change the raw material at least into a liquid state, and the raw material is subjected to a dehydrogenation condensation reaction, to thereby produce a pentacene multimer. A higher, namely, quaternary or higher pentacene multimer can be produced by this production method.

Description

  The present invention relates to a pentacene multimer having a similar structure of graphene and a method for producing the same.

  Graphene is a structure in which benzene rings are spread in a two-dimensional plane, and has attracted attention because it exhibits excellent mechanical strength and electronic conductivity. As a method for producing this graphene, a method of physically peeling graphite using a scotch tape, a method of thermally decomposing a SiC substrate, and the like are known.

  On the other hand, pentacene is a polycyclic aromatic hydrocarbon in which five benzene rings are linearly condensed. Regarding this pentacene, in Non-Patent Document 1, for the purpose of sublimation purification of pentacene, pentacene was heated while continuously flowing argon gas in a reaction apparatus. As a result, pentacene dimer and 3 It is disclosed that a powder containing a monomer has precipitated. The heating conditions at this time were an electric furnace temperature of 320 to 375 ° C., and an argon gas flow rate of 10 to 70 mL / min.

  Further, in Non-Patent Document 2, in relation to Non-Patent Document 1, pentacene dimer (peripentacene) is generated from pentacene as a result of studying the production pathway of pentacene dimer using first principle calculation. It has been pointed out that 6,13-dihydropentacene makes an important contribution to the process.

J. Am. Chem. Soc. 127, 3069-3075 (2005). J. Am. Chem. Soc. 129, 6536-6546 (2007).

  By the way, the above-described method for producing graphene has a problem that only a relatively small amount of graphene can be obtained, which is not suitable for industrial mass production.

  Therefore, as a solution to this problem, the present inventor believes that a bottom-up method in which a chemical polymerization reaction is performed using a low molecular weight organic molecule as a starting material is effective.

  Specifically, a method of synthesizing a pentacene multimer in which a plurality of pentacenes are bonded in a two-dimensional plane by dehydrogenating and condensing pentacene is considered suitable for industrial mass production. Since this pentacene multimer has a graphene-like structure, it can be expected to have characteristics similar to graphene, and can be expected to be used as a new electronic material and energy material.

  However, as such a pentacene multimer, as disclosed in Non-Patent Documents 1 and 2, only a trimer in which three pentacenes are bonded, that is, a multimer having a relatively low molecular weight up to the third order can be obtained. However, there is no method for producing a quaternary or higher multimer.

  In view of the above points, an object of the present invention is to provide a fourth or higher order pentacene multimer and a method for producing a pentacene multimer that can be produced.

  In order to achieve the above-mentioned object, the reason why a fourth-order or higher pentacene multimer was not obtained in the method described in Non-Patent Document 1 was obtained, and a fourth-order or higher pentacene multimer was obtained based on the results of the study. As a result of studying the method for achieving this, the present invention has been completed.

  That is, in Non-Patent Document 1, since pentacene was heated under the conditions of gas flow for the purpose of sublimation purification of pentacene, the solid state pentacene charged as a raw material sublimates in the reactor, together with the carrier gas. Since it moves, it is thought that continuous reaction for a long time was difficult. Further, in the gas phase reaction involving sublimation in this way, it is considered difficult to obtain a higher-order multimer because the probability of collision between pentacene molecules is low. For these reasons, it is considered that only a relatively low molecular weight polymer up to a trimer was obtained by the method described in Non-Patent Document 1.

  Therefore, the method for producing a pentacene multimer of the present invention uses pentacene as a raw material, heats the raw material in a closed container, makes the raw material at least in a liquid state, and causes the raw material to undergo a dehydrogenative condensation reaction. It is characterized by manufacturing.

  According to this, since pentacene is dehydrocondensed in a sealed container in a liquid state, the movement of pentacene can be suppressed and the pentacene can be reacted continuously over a long period of time compared to the method of Non-Patent Document 1. Can do. In addition, since pentacene is subjected to a dehydrogenative condensation reaction in a liquid state, the probability of collision between pentacene molecules can be made higher than when pentacene is vapor-phase reacted. For this reason, according to the present invention, a higher-order pentacene multimer having a fourth or higher order can be produced.

  In addition, the manufacturing method of the pentacene multimer of this invention can also manufacture the 3rd order or less pentacene multimer.

  In addition, this manufacturing method is extremely simple compared to the above-described graphene manufacturing method, and can be said to be suitable for industrial mass production.

  In the method for producing a pentacene multimer of the present invention, for example, the heating temperature is preferably 325 ° C. to 375 ° C., and the inside of the sealed container before heating is preferably in a vacuum state.

  The pentacene multimer of the present invention is represented by the general formula (I), and is of the fourth or higher order having pentacene as a constituent element.

一般式（I）中のｎは４以上の整数であり、一般式（Ｉ）中の破線は共有結合の位置を示している。ただし、一般式（Ｉ）には、共有結合が、すべての破線の位置に存在する場合に限らず、一部の破線の位置に存在しない場合も含まれる。また、一般式（Ｉ）には、構成要素であるペンタセン同士が、式中の縦方向で正対して結合する場合に限らず、式中の横方向にベンゼン環１つ以上シフトして結合する場合も含まれる。

N in the general formula (I) is an integer of 4 or more, and the broken line in the general formula (I) indicates the position of the covalent bond. However, the general formula (I) includes not only the case where the covalent bond exists at all the positions of the broken lines but also the case where the covalent bond does not exist at the positions of some of the broken lines. In addition, the general formula (I) is not limited to the case where the constituent pentacenes are bonded to each other in the vertical direction in the formula, but are bonded by shifting one or more benzene rings in the horizontal direction in the formula. Cases are also included.

  Since this pentacene multimer has a structure similar to graphene as represented by the general formula (I), it can be expected to have the same characteristics as graphene, and is expected to be used as a new electronic material and energy material. it can.

  The general formula (I) includes all of the following general formulas (Ia), (Ib), (Ic), and (Id). For this reason, the pentacene multimer of the present invention is represented by each of the following general formulas (Ia), (Ib), (Ic), and (Id), and is of the fourth or higher order having pentacene as a constituent element. I can also say.

一般式（Ｉａ）中のｎは４以上の整数であり、一般式（Ｉａ）中のすべての破線の位置に共有結合が存在している。また、一般式（Ｉａ）中の構成要素であるペンタセン同士は、すべて、一般式（Ｉａ）中の縦方向で正対して結合している。

N in the general formula (Ia) is an integer of 4 or more, and a covalent bond exists at all broken line positions in the general formula (Ia). In addition, all pentacenes that are constituent elements in the general formula (Ia) are bonded to each other in the longitudinal direction in the general formula (Ia).

一般式（Ｉｂ）中のｎは４以上の整数であり、一般式（Ｉｂ）中の破線は共有結合の位置を示している。ただし、一般式（Ｉｂ）中の一部の破線の位置では、供給結合が存在せず、水素で終端している。また、一般式（Ｉｂ）中の構成要素であるペンタセン同士は、すべて、式中の縦方向で正対して結合している。

N in the general formula (Ib) is an integer of 4 or more, and the broken line in the general formula (Ib) indicates the position of the covalent bond. However, there is no supply bond at the position of a part of broken lines in the general formula (Ib), and it is terminated with hydrogen. In addition, all the pentacenes that are constituent elements in the general formula (Ib) are bonded to each other in the longitudinal direction in the formula.

一般式（Ｉｃ）中のｎは４以上の整数であり、一般式（Ｉｃ）中の構成要素であるペンタセンのうち、１つ以上のペンタセンが、他のペンタセンに対して、式中の横方向にベンゼン環１つ以上シフトしている。また、一般式（Ｉｃ）中の破線は共有結合の位置を示しており、結合するペンタセン同士における一般式（Ｉｃ）中のすべての破線の位置に、共有結合が存在している。

In general formula (Ic), n is an integer of 4 or more, and one or more pentacenes in the general formula (Ic) are constituent elements in general formula (Ic) in the lateral direction in the formula with respect to other pentacenes. One or more benzene rings are shifted to. Moreover, the broken line in general formula (Ic) has shown the position of the covalent bond, and the covalent bond exists in the position of all the broken lines in general formula (Ic) in pentacene to couple | bond together.

一般式（Ｉｄ）中のｎは４以上の整数であり、一般式（Ｉｄ）中の構成要素であるペンタセンのうち、１つ以上のペンタセンが、他のペンタセンに対して、式中の横方向にベンゼン環１つ以上シフトしている。また、一般式（Ｉｄ）中の破線は共有結合の位置を示しており、結合するペンタセン同士における一般式（Ｉｄ）中の一部の破線の位置では、供給結合が存在せず、水素で終端している。

N in the general formula (Id) is an integer of 4 or more, and one or more pentacenes in the general formula (Id) are constituent elements in the general formula (Id) in the lateral direction in the formula. One or more benzene rings are shifted to. Further, the broken line in the general formula (Id) indicates the position of the covalent bond, and at some of the broken line positions in the general formula (Id) between the pentacenes to be bonded, there is no supply bond, and the terminal is terminated with hydrogen. is doing.

2 is a mass spectrum of the substance synthesized in Example 1. It is an enlarged view of the dimer vicinity in FIG. FIG. 2 is an enlarged view of the vicinity of a trimer in FIG. 1. It is an enlarged view of the tetramer vicinity in FIG. FIG. 2 is an enlarged view of the vicinity of a pentamer in FIG. 1. It is an enlarged view of the hexamer vicinity in FIG. FIG. 2 is an enlarged view of the vicinity of a heptamer in FIG. 1. It is an enlarged view of the octamer vicinity in FIG. 2 is a mass spectrum of the substance synthesized in Example 2. FIG. 10 is an enlarged view of the vicinity of a dimer in FIG. 9. FIG. 10 is an enlarged view of the vicinity of a trimer in FIG. 9. 4 is a mass spectrum of the substance synthesized in Example 3. 4 is a mass spectrum of the substance synthesized in Example 4. 6 is a mass spectrum of the substance synthesized in Example 5. 7 is a mass spectrum of the substance synthesized in Example 6. 2 is a mass spectrum of a substance recovered in Comparative Example 1. 4 is a mass spectrum of a substance recovered in Comparative Example 2. 4 is a mass spectrum of a substance recovered in Comparative Example 3.

(Pentacene multimer)
Pentacene is represented by the following formula (II), and the pentacene multimer of the present invention is a higher-order multimer of the fourth or higher order comprising this pentacene as a constituent element. ).

一般式（Ｉ）中のｎは４以上の整数であり、一般式（Ｉ）中の破線はペンタセン同士の共有結合の位置を示している。

N in the general formula (I) is an integer of 4 or more, and the broken line in the general formula (I) indicates the position of the covalent bond between pentacenes.

  However, in the general formula (I), not all broken line positions need to be covalent bonds. Specifically, as shown in the following formula (IV), a covalent bond does not exist at a part of the broken line in the general formula (I), and it may be terminated with hydrogen.

  In the general formula (I), the pentacenes as constituent elements do not need to be bonded straight in the vertical direction, and may be shifted in the horizontal direction as in the following formula (V).

  As specific examples of the general formula (I), structural examples when n = 4 are shown in formula (III), formula (IV), and formula (V).

式（ＩＩＩ）で表されるペンタセン４量体は、構成要素であるペンタセン同士がすべて正対しており、一般式（Ｉ）中の破線の位置のすべてが共有結合である。すなわち、式（ＩＩＩ）中の上下に隣り合うペンタセン同士では、一方のペンタセンの４、５、６、７、８位と、他方のペンタセンの１、１４、１３、１２、１１位との間に、それぞれ、共有結合が存在している。

In the pentacene tetramer represented by the formula (III), all the pentacene constituents are directly facing each other, and all the positions of the broken lines in the general formula (I) are covalent bonds. That is, in pentacene adjacent vertically in formula (III), between the 4, 5, 6, 7, 8 positions of one pentacene and the 1, 14, 13, 12, 11 positions of the other pentacene. Each has a covalent bond.

式（ＩＶ）で表されるペンタセン４量体は、構成要素であるペンタセン同士がすべて正対しているが、上から１段目と２段目のペンタセン同士では、４位と１位との間、５位と１４位との間には、供給結合が存在していない。また、上から３段目と４段目のペンタセン同士では、７位と１２位との間、８位と１１位との間には、共有結合が存在していない。

In the pentacene tetramer represented by the formula (IV), all the pentacene constituents are directly facing each other, but between the first and second pentacenes from the top, it is between the 4th and 1st positions. There is no supply coupling between the 5th and 14th positions. Further, in the third and fourth pentacenes from the top, no covalent bond exists between the 7th and 12th positions and between the 8th and 11th positions.

式（Ｖ）で表されるペンタセン４量体は、上から２段目のペンタセンが、１段目のペンタセンに対して、ベンゼン環１つ分横方向にシフトしており、１段目のペンタセンの４、５、６、７位の位置と、それに対向する２段目のペンタセンの１４、１３、１２、１１位の位置との間に、それぞれ、共有結合が存在している。

In the pentacene tetramer represented by the formula (V), the second-stage pentacene is shifted laterally by one benzene ring with respect to the first-stage pentacene. Covalent bonds exist between the positions 4, 5, 6, and 7 of the second position and positions 14, 13, 12, and 11 of the second-stage pentacene that face each other.

  In the formula (V), one pentacene (second-stage pentacene) is shifted laterally by one benzene ring relative to the other pentacene (first-stage pentacene). However, one or more pentacenes may be shifted laterally with respect to other pentacenes, and may be shifted laterally by two or more benzene rings between the bonded pentacenes.

  In the formula (V), all of the opposing benzene rings are covalently bonded to each other in the bonded pentacene, but no covalent bond exists in a part of the opposing benzene rings and the hydrogen is terminated with hydrogen. May be.

(Method for producing pentacene multimer)
In the method for producing a pentacene multimer of the present invention, pentacene is used as a raw material, and this raw material is heated in a sealed container to produce the pentacene multimer.

  Specifically, pentacene powder is put into a sealed container, the inside of the sealed container is evacuated, and the raw material in the sealed container is heated in this state. The vacuum state here means a state in which a substance such as oxygen that reacts with the raw material is not substantially contained. By sealing the inside of the sealed container in a vacuum state, the raw material can be dehydrogenatively condensed without reacting with a substance such as oxygen.

  Note that, as long as the raw material can be dehydrogenatively condensed without reacting with a substance such as oxygen, the inside of the sealed container may be an inert gas atmosphere without being limited to a vacuum state.

  At the time of heating the raw material, the raw material is at least in a liquid state, and the raw material is subjected to a dehydrogenative condensation reaction in this state. “At least in the liquid state” means that the entire raw material is liquid, or the majority of the raw material is liquid and a part of the raw material remains solid, or the majority of the raw material is liquid and part of the raw material. The case where is vaporized is included. At this time, it is preferable that most of the raw material is in a liquid state (the raw material is mainly in a liquid state).

  Accordingly, the heating temperature is a temperature at which the polymer is melted and dehydrogenatively condensed to obtain a high molecular weight multimer. Specifically as this temperature, 325 to 375 degreeC is mentioned. As can be seen from the examples described later, at a temperature lower than 325 ° C. (for example, 310 ° C.), the raw material remains pentacene even when heated, and at a temperature higher than 375 ° C. (for example, 425 ° C.), This is because by-products other than multimers are produced in large quantities, and higher-order multimers cannot be obtained.

  According to this method for producing a pentacene multimer, a fourth or higher order pentacene multimer can be produced. The reason is considered as follows.

  That is, the raw material is heated in a sealed space, and the raw material is at least in a liquid phase, and the raw material is subjected to a dehydrogenative condensation reaction while suppressing sublimation of the raw material. be able to. Further, by making the raw material at least a liquid phase, it is possible to increase the collision probability of pentacene molecules compared to the case where the raw material is a gas phase. In addition, since the raw material is heated in an airtight container, even if a part of the raw material becomes a gas phase, the phase equilibrium between the liquid phase and the gas phase of the raw material can be maintained, and the raw material can be maintained in the liquid phase. It becomes easy. Therefore, in order to maintain the raw material exclusively in the liquid phase, it is preferable that the volume of the sealed container is small.

  In this method for producing a pentacene multimer, as can be seen from the results of Examples 1 and 2 to be described later, the order (molecular weight) of the produced multimer and its distribution are changed by changing the amount of raw material charged into the sealed container. It is possible to control.

  In addition, although the example below shows an example in which a multimer (dimer to octamer) having an order of 2 to 8 is produced, according to this method for producing a pentacene multimer, the order is 9 The production of the above multimers is also possible.

  Examples of the present invention and comparative examples are shown below.

  The pentacene powder and 6,13-dihydropentacene powder used in Examples and Comparative Examples are pentacene powder manufactured by Kurokin Kasei Co., Ltd. (endothermic peak top value of differential scanning calorimetry (DSC): 416 ° C.), black 6,13-dihydropentacene powder (purity measured by high performance liquid chromatography (HPLC): 99%) manufactured by Kinkasei Co., Ltd.

Moreover, the measurement conditions of the mass spectrum (LDI-TOF-MS) performed by the Example and the comparative example are as follows.
-Device name: JMS-S3000
-Manufacturer name: JEOL
・ Matrix: Not used ・ Laser wavelength: 349 nm
Detection mode: positive ion mode (Example 1)
30 mg of pentacene powder as a raw material was sealed in a cylindrical quartz tube having an inner diameter of 8 mm, a length of 150 mm, and a volume of 7.54 × 10 ⁻⁶ m ³ under a vacuum condition of 2 Pa or less. The raw material in the quartz tube was heated at 325 ° C. for 10 hours.

  During this heating, it was visually confirmed that the raw material was melted and present in the quartz tube. Therefore, it can be said that the raw material did not move from the heating place during this heating.

  After completion of the heating, the quartz tube was cooled to room temperature, and solids present in the quartz tube were collected. The process of washing and filtering the solid with toluene was repeated until the color of the washing became colorless and transparent. Thereby, solid content which did not melt | dissolve in toluene among collect | recovered solid substances was collect | recovered as a product.

  Subsequently, mass spectra (LDI-TOF-MS) were measured for the recovered products. FIG. 1 shows the mass spectrum of the product of Example 1.

  From FIG. 1, it was confirmed that the product of Example 1 contained all of pentacene dimer to octamer.

FIG. 2 shows an enlarged view around the dimer in FIG. The lower part in FIG. 2 is the actual measurement value, and the upper part is C ₄₄ H ₁₄ : C ₄₄ H ₁₆ : C ₄₄ H ₁₈ : C ₄₄ H ₂₀ : C ₄₄ H ₂₂ : C ₄₄ H ₂₄ : C ₄₄ H ₂₆ : C ₄₄ H ₂₈ : C ₄₅ H ₂₁ = Theoretical spectrum calculated under the conditions of 15: 4: 100: 30: 30: 12: 9: 2: 5: 17.

As shown in FIG. 2, since the actually measured value is in agreement with the theoretical spectrum, the molecular formula of the dimer contained in the product of Example 1 is C ₄₄ H ₁₄ , C ₄₄ H ₁₆ , C _44. H ₁₈ , C ₄₄ H ₂₀ , C ₄₄ H ₂₂ , C ₄₄ H ₂₄ , C ₄₄ H ₂₆ , C ₄₄ H ₂₈ , C ₄₅ H ₂₁ may be mentioned. Examples of possible structures for these molecular formulas are shown below.

図３に、図１中の３量体付近の拡大図を示す。図３中の下段は実測値であり、上段はC₆₆H₁₆：C₆₆H₁₈：C₆₆H₂₀：C₆₆H₂₂：C₆₆H₂₄：C₆₆H₂₆：C₆₆H₂₈：C₆₆H₃₀：C₆₆H₃₂：C₆₆H₃₄：C₆₆H₃₆：C₆₆H₃₈：C₆₆H₄₀：C₆₆H₄₂＝11：14：35：67：100：70：44：21：12：13：4：8：7：7の条件で算出した理論スペクトルである。

FIG. 3 shows an enlarged view of the vicinity of the trimer in FIG. The lower row in FIG. 3 is the actual measurement value, and the upper row is C ₆₆ H ₁₆ : C ₆₆ H ₁₈ : C ₆₆ H ₂₀ : C ₆₆ H ₂₂ : C ₆₆ H ₂₄ : C ₆₆ H ₂₆ : C ₆₆ H ₂₈ : C _{66 H 30: C 66 H 32:} C 66 H 34: C 66 H 36: C 66 H 38: C 66 H 40: C 66 H 42 = 11: 14: 35: 67: 100: 70: 44: 21: 12 : Theoretical spectrum calculated under the conditions of 13: 4: 8: 7: 7.

As shown in FIG. 3, since the measured values are in agreement with the theoretical spectrum, the molecular formula of the trimer contained in the product of Example 1 is C ₆₆ H ₁₆ , C ₆₆ H ₁₈ , C _{66. H 20, C 66 H 22,} C 66 H 24, C 66 H 26, C 66 H 28, C 66 H 30, C 66 H 32, C 66 H 34, C 66 H 36, C 66 H 38, C 66 H ₄₀ and C ₆₆ H ₄₂ may be mentioned. Examples of possible structures for these molecular formulas are shown below.

図４に、図１中の４量体付近の拡大図を示す。図４中の下段は実測値であり、上段はC₈₈H₂₀：C₈₈H₂₂：C₈₈H₂₄：C₈₈H₂₆：C₈₈H₂₈：C₈₈H₃₀：C₈₈H₃₂：C₈₈H₃₄：C₈₈H₃₆：C₈₈H₃₈：C₈₈H₄₀：C₈₈H₄₂：C₈₈H₄₄：C₈₈H₄₆：C₈₈H₄₈：C₈₈H₅₀：C₈₈H₅₂：C₈₈H₅₄：C₈₈H₅₆＝22：18：46：58：86：100：96：68：50：22：21：9：18：2：8：8：5：5：3の条件で算出した理論スペクトルである。

FIG. 4 shows an enlarged view of the vicinity of the tetramer in FIG. The lower part of FIG. 4 shows actual measured values, and the upper part shows C ₈₈ H ₂₀ : C ₈₈ H ₂₂ : C ₈₈ H ₂₄ : C ₈₈ H ₂₆ : C ₈₈ H ₂₈ : C ₈₈ H ₃₀ : C ₈₈ H ₃₂ : C ₈₈ H ₃₄ : C ₈₈ H ₃₆ : C ₈₈ H ₃₈ : C ₈₈ H ₄₀ : C ₈₈ H ₄₂ : C ₈₈ H ₄₄ : C ₈₈ H ₄₆ : C ₈₈ H ₄₈ : C ₈₈ H ₅₀ : C ₈₈ H ₅₂ : C ₈₈ H ₅₄ : C ₈₈ H ₅₆ = Calculated under the conditions of 22: 18: 46: 58: 86: 100: 96: 68: 50: 22: 21: 9: 18: 2: 8: 8: 5: 5: 3 It is a theoretical spectrum.

As shown in FIG. 4, since the measured values are in agreement with the theoretical spectrum, the molecular formula of the tetramer contained in the product of Example 1 is C ₈₈ H ₂₀ , C ₈₈ H ₂₂ , C _88. H ₂₄ , C ₈₈ H ₂₆ , C ₈₈ H ₂₈ , C ₈₈ H ₃₀ , C ₈₈ H ₃₂ , C ₈₈ H ₃₄ , C ₈₈ H ₃₆ , C ₈₈ H ₃₈ , C ₈₈ H ₄₀ , C ₈₈ H ₄₂ , C ₈₈ H ₄₄ , C ₈₈ H ₄₆ , C ₈₈ H ₄₈ , C ₈₈ H ₅₀ , C ₈₈ H ₅₂ , C ₈₈ H ₅₄ , C ₈₈ H ₅₆ may be mentioned. Examples of possible structures for these molecular formulas are shown below.

図５に、図１中の５量体付近の拡大図を示す。図５中の分子量の一例より、実施例１の生成物に含まれる５量体の分子式としては、例えば、C₁₁₀H₃₀、C₁₁₀H₃₆が挙げられる。これらの分子式について、考えられる構造例を下記に示す。

FIG. 5 shows an enlarged view of the vicinity of the pentamer in FIG. As an example of the molecular weight in FIG. 5, the molecular formula of the pentamer contained in the product of Example 1 includes, for example, C ₁₁₀ H ₃₀ and C ₁₁₀ H ₃₆ . Examples of possible structures for these molecular formulas are shown below.

図６に、図１中の６量体付近の拡大図を示す。図６中の分子量の一例より、実施例１の生成物に含まれる６量体の分子式としては、例えば、C₁₃₂H₃₄、C₁₃₂H₄₂、C₁₃₂H₄₄、C₁₃₂H₄₆が挙げられる。これらの分子式について、考えられる構造例を下記に示す。

FIG. 6 shows an enlarged view of the vicinity of the hexamer in FIG. As an example of the molecular weight in FIG. 6, the molecular formula of the hexamer contained in the product of Example 1 includes, for example, C ₁₃₂ H ₃₄ , C ₁₃₂ H ₄₂ , C ₁₃₂ H ₄₄ , and C ₁₃₂ H _46. . Examples of possible structures for these molecular formulas are shown below.

図７に、図１中の７量体付近の拡大図を示す。図７中の分子量の一例より、実施例１の生成物に含まれる７量体の分子式としては、例えば、C₁₅₄H₃₈、C₁₅₄H₄₀、C₁₅₄H₄₂が挙げられる。これらの分子式について、考えられる構造例を下記に示す。

FIG. 7 shows an enlarged view of the vicinity of the heptamer in FIG. As an example of the molecular weight in FIG. 7, examples of the molecular formula of the heptamer contained in the product of Example 1 include C ₁₅₄ H ₃₈ , C ₁₅₄ H ₄₀ , and C ₁₅₄ H ₄₂ . Examples of possible structures for these molecular formulas are shown below.

図８に、図１中の８量体付近の拡大図を示す。図７中の分子量の一例より、実施例１の生成物に含まれる８量体の分子式としては、例えば、C₁₇₆H₄₂、C₁₇₆H₅₂が挙げられる。これらの分子式について、考えられる構造例を下記に示す。

FIG. 8 shows an enlarged view of the vicinity of the octamer in FIG. As an example of the molecular weight in FIG. 7, the molecular formula of the octamer contained in the product of Example 1 includes, for example, C ₁₇₆ H ₄₂ and C ₁₇₆ H ₅₂ . Examples of possible structures for these molecular formulas are shown below.

（実施例２）
ペンタセン粉末の仕込み量を30 m から100 mgに変更した点を除いて、実施例１と同様に生成物を合成し、マススペクトルの測定を行った。図９に実施例２の生成物のマススペクトを示す。

(Example 2)
The product was synthesized in the same manner as in Example 1 except that the charged amount of pentacene powder was changed from 30 m to 100 mg, and the mass spectrum was measured. FIG. 9 shows the mass spectrum of the product of Example 2.

  From FIG. 9, it was confirmed that the product of Example 2 contained all of pentacene dimer to pentamer.

  From the results of Examples 1 and 2, when it is desired to obtain higher order multimers, it is only necessary to reduce the amount of raw materials charged, and conversely, when it is desired to increase the proportion of dimers occupying the entire product. It can be seen that the raw material charge amount should be increased.

FIG. 10 shows an enlarged view of the vicinity of the dimer in FIG. The lower part of FIG. 10 is the actual measurement value, and the upper part is C ₄₄ H ₁₄ : C ₄₄ H ₁₆ : C ₄₄ H ₁₈ : C ₄₄ H ₂₀ : C ₄₄ H ₂₂ : C ₄₄ H ₂₄ : C ₄₄ H ₂₆ : C ₄₄ H ₂₈ : C ₄₅ H ₂₁ = Theoretical spectrum calculated under the condition of 3: 9: 100: 41: 27: 3: 4: 2: 5.

As shown in FIG. 10, since the actually measured value is consistent with the theoretical spectrum, the molecular formula of the dimer contained in the product of Example 2 is, for example, C ₄₄ H ₁₄ , C ₄₄ H ₁₆ , C ₄₄ H ₁₈ , C ₄₄ H ₂₀ , C ₄₄ H ₂₂ , C ₄₄ H ₂₄ , C ₄₄ H ₂₆ , C ₄₄ H ₂₈ , C ₄₅ H ₂₁ may be mentioned. These structural examples are the same as those in the first embodiment.

FIG. 11 shows an enlarged view of the vicinity of the trimer in FIG. The lower part in FIG. 11 is the actual measurement value, and the upper part is C ₆₆ H ₁₆ : C ₆₆ H ₁₈ : C ₆₆ H ₂₀ : C ₆₆ H ₂₂ : C ₆₆ H ₂₄ : C ₆₆ H ₂₆ : C ₆₆ H ₂₈ : C _{66 H 30: C 66 H 32:} C 66 H 34: C 66 H 36: C 66 H 38: C 66 H 40: C 66 H 42 = 22: 36: 43: 78: 96: 85: 100: 61: 41 : Theoretical spectrum calculated under the conditions of 46: 21: 27: 15: 3.

As shown in FIG. 11, since the actually measured value is consistent with the theoretical spectrum, the molecular formula of the trimer contained in the product of Example 2 is, for example, C ₆₆ H ₁₆ , C ₆₆ H ₁₈ , C ₆₆ H ₂₀ , C ₆₆ H ₂₂ , C ₆₆ H ₂₄ , C ₆₆ H ₂₆ , C ₆₆ H ₂₈ , C ₆₆ H ₃₀ , C ₆₆ H ₃₂ , C ₆₆ H ₃₄ , C ₆₆ H ₃₆ , C ₆₆ H ₃₈ , C ₆₆ H ₄₀ and C ₆₆ H ₄₂ may be mentioned. These structural examples are the same as those in the first embodiment.
(Example 3)
The product was synthesized in the same manner as in Example 1 except that 15 mg of pentacene powder and 15 mg of 6,13-dihydropentacene powder represented by the following formula (VI) were used in combination, and the mass spectrum was measured. Went.

図１２に実施例３の生成物のマススペクトを示す。図１２より、実施例３の生成物には、ペンタセンの２量体から６量体までのすべてが含まれていることが確認された。

FIG. 12 shows the mass spectrum of the product of Example 3. From FIG. 12, it was confirmed that the product of Example 3 contained all of pentacene dimer to hexamer.

  Comparing Examples 1 and 3, it can be seen that when 6,13-dihydropentacene is mixed without changing the total amount of raw materials, the order of the resulting multimer is lowered.

Therefore, by mixing 6,13-dihydropentacene with pentacene powder, the molecular weight of the resulting multimer (multimer order) can be controlled, and mixing with 6,13-dihydropentacene is especially important This can be said to be effective when it is desired to keep the value low.
Example 4
The product was synthesized in the same manner as in Example 1 except that the heating temperature was changed to 340 ° C., and the mass spectrum was measured. FIG. 13 shows the mass spectrum of the product of Example 4. From FIG. 13, it was confirmed that the product of Example 4 contained all of pentacene dimer to pentamer.
(Example 5)
The product was synthesized in the same manner as in Example 1 except that the heating temperature was changed to 350 ° C., and the mass spectrum was measured. FIG. 14 shows the mass spectrum of the product of Example 5. From FIG. 14, it was confirmed that the product of Example 5 contained all of pentacene dimer to pentamer.
(Example 6)
The product was synthesized in the same manner as in Example 1 except that the heating temperature was changed to 375 ° C., and the mass spectrum was measured. FIG. 15 shows the mass spectrum of the product of Example 6. From FIG. 15, it was confirmed that the product of Example 6 contained all of pentacene dimer to tetramer.
(Comparative Example 1)
The raw material was heated in the same manner as in Example 1 except that the raw material was changed from pentacene powder to 30 mg of 6,13-dihydropentacene powder, and the mass spectrum of the recovered substance was measured. FIG. 16 shows this mass spectrum.

From FIG. 16, it was confirmed that the product of Comparative Example 1 contains only pentacene dimer. From this, it can be seen that when the raw material does not contain pentacene at all, a pentacene multimer other than the dimer cannot be obtained. Moreover, in the comparative example 1, it was confirmed that there are few products and many raw materials remain.
(Comparative Example 2)
The raw material was heated in the same manner as in Example 1 except that the heating temperature was changed to 310 ° C., and then the mass spectrum of the recovered substance was measured. FIG. 17 shows this mass spectrum.

From FIG. 17, it was confirmed that the polymerization reaction of the raw material did not occur in the case of Comparative Example 2. This shows that when the heating temperature is 310 ° C. or lower, a pentacene multimer cannot be obtained.
(Comparative Example 3)
The raw material was heated in the same manner as in Example 1 except that the heating temperature was changed to 425 ° C., and then the mass spectrum of the recovered substance was measured. FIG. 18 shows this mass spectrum.

  From FIG. 18, it was confirmed that the product of Comparative Example 3 contained only pentacene dimer and trimer. From this, it is understood that when the heating temperature is 425 ° C. or higher, a fourth-order or higher pentacene multimer cannot be obtained.

  Since the pentacene multimer of the present invention has a graphene-like structure, it can be expected to have the same physical properties as graphene. For example, a negative electrode active material for lithium ion secondary batteries, a conductive auxiliary agent for electrode materials, and a transparent conductive film It can be used as a field effect transistor, an organic thin film solar cell, a reinforcing material added to a polymer to improve mechanical strength, a gas storage material for storing hydrogen, and the like.

Claims (8)

It is represented by the following general formula (I),
A fourth or higher order pentacene multimer having pentacene as a constituent element.

(N in the general formula (I) is an integer of 4 or more, and the broken line in the general formula (I) indicates the position of the covalent bond. However, in the general formula (I), all the covalent bonds are In addition, the general formula (I) includes the case where the constituent pentacenes are arranged in the vertical direction in the formula. (It is not limited to the case of bonding directly and includes the case of bonding by shifting one or more benzene rings in the lateral direction in the formula.) It is represented by the following general formula (Ia),
A fourth or higher order pentacene multimer having pentacene as a constituent element.

(In general formula (Ia), n is an integer of 4 or more, and covalent bonds exist at all broken line positions in general formula (Ia). All of certain pentacenes are bonded in the longitudinal direction in the general formula (Ia). It is represented by the following general formula (Ib),
A fourth or higher order pentacene multimer having pentacene as a constituent element.

(N in the general formula (Ib) is an integer of 4 or more, and the broken line in the general formula (Ib) indicates the position of the covalent bond. However, the positions of some broken lines in the general formula (Ib) In the formula (Ib), all the pentacenes that are constituent elements in the general formula (Ib) are bonded to each other in the longitudinal direction. It is represented by the following general formula (Ic),
A fourth or higher order pentacene multimer having pentacene as a constituent element.

(N in the general formula (Ic) is an integer of 4 or more, and one or more pentacenes in the general formula (Ic) are constituent elements in the general formula (Ic). One or more benzene rings are shifted in the direction, and the broken line in the general formula (Ic) indicates the position of the covalent bond, and the positions of all the broken lines in the general formula (Ic) between the bonded pentacenes are , A covalent bond exists.) It is represented by the following general formula (Ib),
A fourth or higher order pentacene multimer having pentacene as a constituent element.

(N in the general formula (Id) is an integer of 4 or more, and one or more pentacenes in the general formula (Id) are constituent elements in the general formula (Id). One or more benzene rings are shifted in the direction, and the broken line in the general formula (Id) indicates the position of the covalent bond, and the position of a part of the broken line in the general formula (Id) between the pentacenes to be bonded. (There is no supply bond and it is terminated with hydrogen.) Using pentacene as a raw material,
A method for producing a pentacene multimer, characterized in that a pentacene multimer is produced by heating the raw material in a sealed container to bring the raw material into at least a liquid state and subjecting the raw material to a dehydrogenative condensation reaction.   The method for producing a pentacene multimer according to claim 6, wherein the raw material is heated at a temperature of 325C to 375C. The method for producing a pentacene multimer according to claim 6 or 7, wherein the inside of the sealed container before heating is in a vacuum state.

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