JP4099526B2 - Separation and purification of porphyrin dimer derivatives and carbon nanotubes using them - Google Patents

Description

  The present invention relates to a novel compound porphyrin dimer capable of forming a complex with carbon nanotubes, a carbon nanotube complex in which the porphyrin dimer and carbon nanotubes are combined and solubilized in a solvent, and carbon nanotubes through such solubilization. The present invention relates to a method for structural selection, separation and purification.

  Carbon nanotubes are one of the most noticeable materials for next-generation electronic devices. They have excellent electrical and thermal conductivity, very strong mechanical strength, and are thermally stable. It is an excellent material for occlusion.

  A carbon nanotube has a structure in which a graphene sheet is wound in a cylindrical shape, and shows different conductive properties such as metallic and semiconducting depending on the difference in diameter and winding method. However, it is difficult to separate the carbon nanotubes due to such a difference in winding method. Carbon nanotubes are difficult to purify because of poor reactivity and solubility. A method for efficiently purifying and separating such carbon nanotubes is desired.

  As a method for increasing the solubility of carbon nanotubes, Patent Document 1 discloses that a polymer is bonded to the outer wall of the carbon nanotubes by non-covalent interaction to solubilize the carbon nanotubes. Patent Document 2 discloses a carbon nanotube compounded by winding a polymer around the carbon nanotube.

  On the other hand, Patent Document 3 suggests that carbon nanotubes and porphyrin can be bonded. Further, Non-Patent Document 1 discloses an example in which carbon nanotubes are complexed and solubilized using porphyrin.

JP 2004-2850 A JP-T-2004-506530 JP 2004-315786 A Huaping Li, Bing Zhou, Yi Lin, Lingrong Gu, Wei Wang, K.A. Shiral Feronando, Satish Kumar, Lawrence F. Allard, and Ya-Ping Sun., J. Am. Chem. Soc. 2004, 126, 1014

  In order to solubilize carbon nanotubes, the present invention was made to structurally select carbon nanotubes having different conductive properties. A novel compound that forms a complex with carbon nanotubes by non-covalent bonds, the novel It is an object to provide a carbon nanotube composite in which compounds are non-covalently bound and solubilized in a solvent, and further a method for structurally selecting, separating and purifying carbon nanotubes using such composite and solubilization. And

（式Ｉ中、ｍは０〜１７）
で示されるもの（ただし、パラポルフィリンダイマー誘導体を除く）である。 The porphyrin dimer derivative according to claim 1 made to achieve the above object is represented by the following chemical formula I:

(In Formula I, m is 0 to 17)
(Excluding paraporphyrin dimer derivatives) .

（式Ａ中、ｍは０〜１７）
で示されるポルフィリン誘導体を合成し、続いて該ポルフィリン誘導体と9,9-ジヘキシルフルオレン-2,7-ジボロン酸とを反応させることを特徴とする。 The method for producing a porphyrin dimer derivative according to claim 2 is characterized in that at least one bromobenzaldehyde selected from 2-bromobenzaldehyde and 3- bromobenzaldehyde and 4-alkylbenzaldehyde (the carbon number of the alkyl group is 1-18) and pyrrole, the following formula A

(In Formula A, m is 0 to 17)
And then reacting the porphyrin derivative with 9,9-dihexylfluorene-2,7-diboronic acid.

When 2-bromobenzaldehyde is used, a porphyrin dimer derivative in which porphyrin and fluorene are linked at the ortho position (hereinafter abbreviated as ortho-porphyrin dimer derivative) as in Formula II is obtained, and when 3-bromobenzaldehyde is used, porphyrin and fluorene as formula III are linked porphyrin dimer derivative (hereinafter, meta - abbreviated as porphyrin dimer derivative) in the meta position is obtained, et al.

The carbon nanotube composite described in claim 3 of the claims is that in which the porphyrin dimer derivative represented by the chemical formula I (excluding the paraporphyrin dimer derivative) is bonded to the carbon nanotube.

（式II中、ｍは０〜１７）
で示されるポルフィリンダイマー誘導体が結合しているカーボンナノチューブ複合体から分離されたことを特徴とする。 The carbon nanotube having a structure showing metallic conductivity according to claim 4 is represented by the following chemical formula II.

(In Formula II, m is 0 to 17)
It is characterized by being separated from the carbon nanotube complex to which the porphyrin dimer derivative represented by

（式III中、ｍは０〜１７）
で示されるポルフィリンダイマー誘導体が結合しているカーボンナノチューブ複合体から分離されたことを特徴とする。 The carbon nanotube having a structure showing semiconducting conductivity according to claim 5 is represented by the following chemical formula III:

(In Formula III, m is 0 to 17)
It is characterized by being separated from the carbon nanotube complex to which the porphyrin dimer derivative represented by

The method for separating and purifying carbon nanotubes as claimed in claim 6 is characterized in that acetic acid is added to a dispersion in which the carbon nanotube complex according to any of claims 3, 4 and 5 is dispersed in an organic solvent. The carbon nanotubes are precipitated by adding an acid selected from a dilute hydrochloric acid aqueous solution and a dilute sulfuric acid aqueous solution.

The method for separating and purifying the carbon nanotube structure depicting metal-conductive claim 7 of the appended claims, the dispersion prepared by dispersing in an organic solvent of carbon nanotube composite according to claim 4, acetic acid The carbon nanotubes are precipitated by adding an acid selected from a dilute hydrochloric acid aqueous solution and a dilute sulfuric acid aqueous solution.

The method for separating and purifying carbon nanotubes having a semiconducting conductivity structure according to claim 8 is characterized in that acetic acid is added to a dispersion obtained by dispersing the carbon nanotube composite according to claim 5 in an organic solvent. The carbon nanotubes are precipitated by adding an acid selected from a dilute hydrochloric acid aqueous solution and a dilute sulfuric acid aqueous solution.

  It is preferable that both the dilute hydrochloric acid aqueous solution and the dilute sulfuric acid aqueous solution have a pH of 1-2.

  The carbon nanotube used in the present invention may be a single-walled carbon nanotube or a multi-walled carbon nanotube.

  The porphyrin dimer derivative of the present invention is a porphyrin dimer in which two porphyrins are linked via fluorene, and can form a complex with a carbon nanotube by noncovalent bonding. Since the non-covalent bond is not a direct bond, the carbon nanotubes can be easily combined without impairing the original properties. The carbon nanotubes complexed by the porphyrin dimer of the present invention are soluble in the solvent, and the carbon nanotubes can be purified.

  The dispersion in which the carbon nanotube composite of the present invention is dispersed can maintain a stable dispersion state for a long period of time without causing precipitation or separation of the carbon nanotubes.

  When the three-dimensional structure of the porphyrin dimer derivative of the present invention is molecularly designed, carbon nanotubes having a structure showing metallic conductivity and carbon nanotubes having a structure showing semiconducting conductivity can be efficiently and easily selected. The selected carbon nanotubes can be easily separated and recovered by adding acid to the dispersion of the composite. Therefore, it becomes possible to assemble electronic circuits using carbon nanotubes with different electrical properties as nanowires. It is useful as a material for device development.

The synthesis method of porphylene phosphorus dimer derivatives, the para - will be described as an example a porphyrin dimer derivative. A preferred form of the para-porphyrin dimer derivative is synthesized according to the following chemical reaction formula.

  First, 4-bromobenzaldehyde and 4-alkylbenzaldehyde are dissolved in propionic acid. The 4-alkylbenzaldehyde is preferably 4-dodecylbenzaldehyde whose alkyl group has 12 carbon atoms. Subsequently, single-distilled pyrrole is added to this solution and stirred and refluxed to synthesize a porphyrin derivative represented by the chemical formula A. The obtained porphyrin derivative is preferably purified by alumina column chromatography or high performance liquid chromatography.

  Next, an aqueous sodium carbonate solution is added to a solvent in which 9,9-dihexylfluorene-2,7-diboronic acid is dissolved, and the mixture is deaerated under a nitrogen stream. The porphyrin derivative A obtained above is added thereto, and the mixture is stirred and refluxed to react to synthesize a para-porphyrin dimer derivative represented by the chemical formula IV. The obtained porphyrin dimer derivative is preferably purified by silica gel column chromatography or high performance liquid chromatography. The solvent may be any solvent that can dissolve 9,9-dihexylfluorene-2,7-diboronic acid, and is preferably a toluene-tetrahydrofuran mixed solvent.

  An ortho-porphyrin dimer derivative represented by the above chemical formula II can be obtained by synthesizing in the same procedure using 2-bromobenzaldehyde instead of the 4-bromobenzaldehyde. Further, when 3-bromobenzaldehyde is used in place of the 4-bromobenzaldehyde and synthesized by the same procedure, a meta-porphyrin dimer derivative represented by the chemical formula III can be obtained.

  When the porphyrin dimer derivative of the present invention is added to and dispersed in a solvent in which carbon nanotubes are dispersed, a complex of the carbon nanotube and the porphyrin dimer derivative can be formed. As the porphyrin dimer derivative of the present invention, any of the ortho-porphyrin dimer derivative, the meta-porphyrin dimer derivative, and the para-porphyrin dimer derivative may be used.

  This complex is formed by non-covalent bonds such as π-π interaction and hydrophobic interaction between the porphyrin moiety and the carbon nanotube. Carbon nanotubes are insoluble in solvents and water. However, when carbon nanotubes are complexed with the porphyrin dimer derivative of the present invention, the carbon nanotubes are solubilized. This is because solvation by the porphyrin dimer derivative in the complex is possible, and the carbon nanotubes are stably dispersed in the solvent for a long period of time. Here, the solubilization of carbon nanotubes includes a state where the carbon nanotube composite is dissolved in a solvent and a state where the carbon nanotube composite is uniformly dispersed in the solvent for a long period of time.

  A dispersion in which the carbon nanotube composite is dispersed in an organic solvent maintains a uniform dispersion state for 6 months or more without separation and precipitation of the carbon nanotubes. The organic solvent in which the carbon nanotube composite of the present invention is dispersed is preferably tetrahydrofuran, dichloromethane, or dimethylformamide.

  The dispersion when forming the complex and the dispersion of the complex in an organic solvent are preferably performed by ultrasonic treatment.

  The ortho-porphyrin dimer derivative represented by the chemical formula II selectively forms a complex with a carbon nanotube having a structure exhibiting metallic conductivity. In addition, the meta-porphyrin dimer derivative represented by the chemical formula III selectively forms a complex with carbon nanotubes having a structure exhibiting semiconducting conductivity. The conductivity of carbon nanotubes varies depending on the diameter and chirality, and the chirality of carbon nanotubes is classified into a zigzag type, a chiral type, and an armchair type. In the porphyrin dimer derivative of the present invention, the porphyrin portion is strongly adsorbed on the side wall of the carbon nanotube to form a stable complex. At this time, it is considered that the porphyrin dimer derivative recognizes the chirality of the carbon nanotubes based on the difference in the distance and angle between porphyrins in the molecule, and the above-described selectivity is produced at the time of complex formation.

  A dispersion of the carbon nanotube composite, a dispersion of a composite of the ortho-porphyrin dimer derivative and a carbon nanotube having a structure having metallic conductivity, and a structure having a semiconducting conductivity with the meta-porphyrin dimer derivative. When an acid is added to the dispersion liquid of the composite with the carbon nanotube, the non-covalent bond forming each composite is inhibited by the acid, and the porphyrin dimer and the carbon nanotube are separated. Since the separated carbon nanotubes cannot be dispersed in the solvent and precipitate, they can be easily recovered. Therefore, if carbon nanotubes are complexed with the porphyrin dimer derivative of the present invention and purified, and then separated from the purified complex, the desired carbon nanotubes can be obtained with high purity. The acid is preferably acetic acid.

  Examples of the present invention will be described in detail below, but the scope of the present invention is not limited to these examples.

An example of synthesizing porphylene phosphorus dimer derivatives shown in Examples 1-3.

Example 1
Synthesis of para-porphyrin dimer derivatives
2.00 g (7.29 × 10 ⁻³ mol) of 4-dodecylbenzaldehyde and 0.45 g (2.43 × 10 ⁻³ mol) of 4-bromobenzaldehyde are dissolved in 20 ml of propionic acid, and 0.1% of single-distilled pyrrole is dissolved. After adding 65 ml (9.72 × 10 ⁻³ mol), the mixture was stirred and refluxed at 130 ° C. for 2 nights. The reaction solution was cooled to room temperature and concentrated under reduced pressure. The product was purified by alumina column chromatography (dichloromethane: hexane = 1: 1) and high performance liquid chromatography, and 5- (4′-bromophenyl) -10,15,20-tris (4′-dodecylphenyl) porphyrin (A compound in which m = 11 in the formula A and Br is linked at the para position) was obtained.

Next, 0.1 g of 5- (4′-bromophenyl) -10,15,20-tris (4′-dodecylphenyl) porphyrin obtained above in a mixed solvent of 5 ml of toluene and 5 ml of tetrahydrofuran (THF) ( 8.34 × 10 ⁻⁵ mol) was dissolved, and further, 15.3 mg (3.63 × 10 ⁻⁵ mol) of 9,9-dihexylfluorene-2,7-diboronic acid was added and dissolved. Thereto was added 10 ml of 2M sodium carbonate solution, which was thoroughly deaerated under a nitrogen stream, and then tetrakistriphenylphosphine palladium (Pd (PPh ₃ ) ₄ ) was added, followed by stirring and refluxing at 70 ° C. for 3 nights. After cooling to room temperature, the organic layer was extracted with ether, washed twice with water, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The product was purified by silica gel column chromatography (dichloromethane) and high performance liquid chromatography to obtain para-porphyrin dimer (compound of formula IV, m = 11) with a yield of 35%. ¹ H-nuclear magnetic resonance measurement ( ¹ H-NMR) and ¹³ C-nuclear magnetic resonance measurement ( ¹³ C-NMR) and matrix-assisted laser desorption / ionization-time-of-flight mass spectrometry (MALDI-TOF-) of the obtained compound MS) and analysis data support this structure.

¹ H-NMR (CDCl ₃ , 400.13 MHz): δ = 8.98 (d, J = 4.8 Hz, 4 H, Pyrrole H), 8.91 (d, J = 4.8 Hz, 4 H, Pyrrole H), 8.87 (s, 8 H, Pyrrole H), 8.35 (d, J = 8.4Hz, 4H, ArH), 8.11-8.15 (m, 18H, Fluorene H and ArH), 8.00 (d, J = 4.8Hz, 2H, Fluorene H), 7.98 (s , 2H, fluorene H), 7.55-7.58 (m, 12H, ArH), 2.96 (t, J = 7.2Hz, 12H, ArCH 2), 2.28 (t, J = 6.0Hz, 4H, fluorene CH 2), 1.93 (t, J = 8.0Hz, 12H , ArCH 2 CH 2), 1.22-1.60 (m, 124H, CH 2), 0.90 (t, J = 6.8Hz, 18H, CH 3), 0.84 (t, J = 6.8 Hz, 6H, ₂ CH ₃ ),-2.69 (s, 4H, NH)
¹³ C-NMR (CDCl ₃ , 100.61 MHz) δ: 142.40, 139.49, 135.23, 134.61, 126.74, 125.41, 120.39, 120.32, 111.05, 102.31, 101.75, 36.05, 31.99, 31.68, 29.80, 29.76, 29.71, 29.64, 29.44 , 22.75,14.16
MALDI-TOF-MS (Dithranol): m / z = 2570.33 [M + H] ⁺ , C ₁₈₅ H ₂₃₄ NO ₈ calculated value 2569.83

(Example 2)
Synthesis of meta-porphyrin dimer derivatives
A meta-porphyrin dimer (shown in Formula III above) was used in the same manner as in Example 1 except that 0.45 g (2.43 × 10 ⁻³ mol) of 3-bromobenzaldehyde was used instead of 4-bromobenzaldehyde. = 11 compound) in 43% yield. The analytical data of ¹ H-NMR, ¹³ C-NMR and MALDI-TOF-MS of the obtained compound support this structure.

¹ H-NMR (CDCl ₃ , 400.13 MHz): δ = 8.82-8.96 (m, 16H, Pyrrole H), 8.47-8.61 (m, 4H, Fluorene H), 8.19-8.21 (m, 2H, Fluorene H), 8.04-8.14 (m, 8H, ArH), 7.76-7.96 (m, 12H, ArH), 7.54 (d, J = 7.6Hz, 12H, ArH), 2.93 (t, J = 7.4Hz, 12H, ArCH ₂ ) , 1.86-1.97 (m, 16H, CH ₂ ), 1.30 (m, 124H, CH ₂ ), 0.86-0.90 (m, 24H, CH ₃ ),-2.72 (s, 4H, NH)
¹³ C-NMR (CDCl ₃ , 100.61 MHz) δ: 142.39, 139.48, 138.05, 134.57, 126.71, 120.18, 118.42, 108.36, 100.37, 36.00, 31.95, 31.64, 29.76, 29.72, 29.59, 29.39, 22.71, 19.40, 14.12
MALDI-TOF-MS (Dithranol): m / z = 2571.04 [M + H] ⁺ , C ₁₈₅ H ₂₃₄ NO ₈ calculated value 2569.83

(Example 3)
Synthesis of ortho-porphyrin dimer derivatives
An ortho-porphyrin dimer (shown in Formula II above) was used in the same manner as in Example 1 except that 0.45 g (2.43 × 10 ⁻³ mol) of 2-bromobenzaldehyde was used instead of 4-bromobenzaldehyde. = 11 compound) was obtained in a yield of 58%. The analytical data of ¹ H-NMR, ¹³ C-NMR and MALDI-TOF-MS of the obtained compound support this structure.

¹ H-NMR (CDCl ₃ , 400.13 MHz): δ = 8.76 (d, J = 4.8 Hz, 4H, Pyrrole H), 8.72 (d, J = 4.8 Hz, 4H, Pyrrole H), 8.54 (s, 8H, Pyrrole H), 8.10 (m, 6H, ArH), 8.03 (d, J = 7.2Hz, 4H, ArH), 7.96 (d, J = 7.6Hz, 4H, ArH), 7.85 (m, 6H, ArH), 7.67 (d, J = 7.6Hz, 2H, ArH), 7.44-7.56 (m, 12H, ArH), 7.38 (d, J = 7.6Hz, 4H, ArH), 6.69 (s, J = 7.6Hz, 2H, Fluorene H), 6.64 (d, J = 8.0Hz, 2H, Fluorene H), 6.22 (d, J = 8.0Hz, 2H, Fluorene H), 2.89 (t, J = 7.6Hz, 12H, ArCH ₂ ), 1.89 (t, J = 7.6Hz, 12H, ArCH ₂ CH ₂ ), 1.31-1.59 (m, 112H, CH ₂ ), 0.89 (t, J = 6.4Hz, 24H, CH ₃ ),-0.35 (t, J = 7.2Hz, 4H, CH ₂ ),-0.76 (s, 4H, CH ₂ ),-1.55 (s, 8H, CH ₂ ), 2.96 (s, 4H, NH),
¹³ C-NMR (CDCl ₃ , 100.61 MHz) δ: 149.46, 142.24, 142.12, 139.35, 134.57, 134.42, 134.29, 126.65, 126.55, 119.78, 118.58, 108.11, 100.38, 36.06, 36.02, 32.00, 31.69, 29.82, 29.76 , 29.68,29.45,27.35,22.76,21.33,14.17,13.49
MALDI-TOF-MS (Dithranol): m / z = 2569.86 [M + H] ⁺ , C ₁₈₅ H ₂₃₄ NO ₈ calculated value 2569.83

  Next, examples in which composites of porphyrin dimer derivatives and single-walled carbon nanotubes to which the present invention is applied using the porphyrin dimer derivatives obtained in Examples 1 to 3 were prepared in Examples 4 to 6. An example in which a dispersion of the composite obtained in 6 was prepared is shown in Example 7, and an example in which a composite that is not applicable to the present invention is prepared is shown in Comparative Example 1.

Example 4
Preparation of complex of single-walled carbon nanotube and para-porphyrin dimer In a centrifuge tube, 1 mg of para-porphyrin dimer obtained in Example 1 was dissolved in 10 ml of hexane to obtain Solution 1. 1 mg of single-walled carbon nanotubes was added to Solution 1 and sonication was performed overnight to form a complex of single-walled carbon nanotubes and para-porphyrin dimer. Centrifugation was then performed at 3000 G for 20 minutes, the supernatant (Solution 2) was removed, and the precipitate was dried under reduced pressure. At this time, only the porphyrin dimer is dissolved in Solution 2, and the precipitate is a mixture of the single-walled carbon nanotubes not forming a complex and the complex. The obtained dried product was dissolved in 5 ml of THF, dispersed by sonication, and centrifuged at 2000 G for 15 minutes. The supernatant (Solution 3) was collected, and the precipitate was dissolved again in 5 ml of THF, dispersed by sonication, and centrifuged at 2000 G for 15 minutes. At this time, the complex is dissolved in Solution 3, and the precipitate is a single-walled carbon nanotube that does not form a complex. The supernatant (Solution 4) was collected, and Solution 3 and Solution 4 were transferred to a microtube and centrifuged to further remove the precipitate. The supernatant was concentrated under reduced pressure, and the remaining solid was used as a complex of single-walled carbon nanotubes and para-porphyrin dimer (para-complex). Hexane was added to the obtained para-complex and centrifuged to remove the supernatant, and then the precipitate was dissolved in THF and concentrated under reduced pressure to purify the para-complex.

(Example 5)
Preparation of complex of single-walled carbon nanotube and meta-porphyrin dimer Example 4 except that the meta-porphyrin dimer obtained in Example 2 was used in place of the para-porphyrin dimer obtained in Example 1 In the same manner as above, a composite (meta-composite) of a single-walled carbon nanotube and a meta-porphyrin dimer was prepared.

(Example 6)
Preparation of complex of single-walled carbon nanotube and ortho-porphyrin dimer Example 4 except that the ortho-porphyrin dimer obtained in Example 3 was used in place of the para-porphyrin dimer obtained in Example 1. In the same manner as described above, a composite (ortho-composite) of a single-walled carbon nanotube and an ortho-porphyrin dimer was prepared.

(Example 7)
Preparation of ortho-complex dispersion liquid 10 mg of THF was added to 1 mg of the ortho-complex obtained in Example 6 and subjected to ultrasonic treatment for 8 hours to prepare a dispersion solution of the ortho-complex.

(Comparative Example 1)
A composite of a single-walled carbon nanotube and a mononuclear porphyrin was prepared in the same manner as in Example 4 except that a mononuclear porphyrin was used instead of the para-porphyrin dimer obtained in Example 1.

  The following evaluation was performed using the compounds obtained in Examples 1 to 3, the composites obtained in Examples 4 to 6, and the dispersion obtained in Example 7.

(Stability evaluation of dispersion)
The dispersion obtained in Example 7 was allowed to stand for 6 months or longer to confirm the dispersion state.

(Near infrared absorption spectrum measurement)
The porphyrin dimer derivative obtained in Examples 1 to 3 and the complex obtained in Examples 4 to 6 were added and dissolved in 500 μl of THF, respectively. 200 μl of each solution was taken, and a solution obtained by diluting it with 1.0 ml of THF was used as a sample, and near-infrared absorption spectra were measured. For the measurement, a near infrared spectrophotometer U-4100 (trade name, manufactured by Hitachi, Ltd.) was used. The measurement results of the para-porphyrin dimer obtained in Example 1 and the para-complex obtained in Example 4 are shown in FIG. 1 (b), and the meta-porphyrin dimer obtained in Example 2 and Example 5 were obtained. The measurement results of the meta-complex are shown in FIG. 1 (c), the ortho-porphyrin dimer obtained in Example 3 and the ortho-complex obtained in Example 6 are shown in FIG. 1 (d). Show. For comparison, FIG. 1A shows the result of measuring the near-infrared absorption spectrum of a solution prepared by adjusting the mononuclear porphyrin and the composite of Comparative Example 1 in the same manner as described above.

(Atomic force microscope observation)
The dispersion obtained in Example 7 was spin-cast on a mica plate, and THF was added dropwise while spinning the mica substrate to remove excess organic substances to prepare a sample. As the atomic force microscope, EX290105 (trade name, manufactured by Thermo Microscopes) was used.

(Raman spectrum measurement)
The composites obtained in Examples 4 to 6 and single-walled carbon nanotubes not forming the composite were each cast on a slide glass, and Raman spectra were measured using a 514 nm laser. For the measurement, a Raman spectrophotometer Hololab 5000 (trade name, manufactured by ST Japan Co., Ltd.) was used. The measurement result of the para-complex obtained in Example 4 was obtained in FIG. 2 (b), the measurement result of the meta-complex obtained in Example 5 was obtained in FIG. The measurement results of the ortho-complex are shown in FIG. Moreover, the result of having measured the Raman spectrum similarly about the composite_body | complex of the comparative example 1 is shown to (a) of FIG.

(Separation of carbon nanotube and porphyrin dimer by addition of acetic acid)
To 1.2 ml of the ortho-complex dispersion solution obtained in Example 7, 20 μl of acetic acid was added and stirred well, and the solution was left overnight. Moreover, the visible ultraviolet absorption spectrum was measured about the solution before and behind acetic acid addition. For the measurement, an ultraviolet-visible spectrophotometer V-570 (trade name, manufactured by JASCO Corporation) was used. The measurement results are shown in FIG.

  When the ortho-complex dispersion solution obtained in Example 7 was allowed to stand, no separation or precipitation was observed, and the solution state was stably maintained for 6 months or more. From this, it was confirmed that a complex of the porphyrin dimer derivative of the present invention and the single-walled carbon nanotube was formed.

  Next, the near-infrared absorption spectrum measurement results will be examined. As is clear from FIG. 1, in the mononuclear porphyrin alone and in the solutions of Examples 1, 2, and 3, only the absorption of the Soret band of porphyrin appears clearly, but the composite of Comparative Example 1 and the Example In the solutions of the complexes of 4, 5, and 6, broad absorption was observed in the vicinity of 1800-2200 nm and below 1600 nm in addition to the Soret band of porphyrin. This absorption is thought to be due to single-walled carbon nanotubes.

  In the atomic force microscope observation, nanotubes in which the bundle structure of single-walled carbon nanotubes was dissolved were observed. The height of this nanotube is about 5 nm, and it is thought that the periphery is covered with a porphyrin dimer. From this observation, it was revealed that the porphyrin dimer derivative of the present invention forms a complex with single-walled carbon nanotubes.

Next, the Raman spectrum measurement result will be examined. As shown in FIG. 2, para - complex, meta - complex, ortho - in all complexes, radial breathing mode is a characteristic spectrum of the nanotubes (171cm ^-1 near) and G band (1570,1593cm ^-1 Near) was observed, and it was revealed that carbon nanotubes were present. Further, since the frequency of each radial breathing mode is slightly increased compared to the spectrum of the single-walled carbon nanotube not forming the complex, the mononuclear porphyrin or the porphyrin dimer of the present invention and the single-walled carbon nanotube As a result, the formation of a bundle structure of nanotubes was impeded.

  Furthermore, the complexes with mononuclear porphyrins and para-complexes showed little change in the spectrum of single-walled carbon nanotubes and each complex, whereas meta-complexes and ortho-complexes A clear peak shift was confirmed in the G band of each complex. When the meta-porphyrin dimer forms a complex, the frequency of the G band increases, and when the ortho-porphyrin dimer forms a complex, the frequency of the G band decreases. From this result, the meta-porphyrin dimer derivative of the present invention selectively forms a complex with carbon nanotubes having a semiconducting conductivity structure, and the ortho-porphyrin dimer derivative of the present invention has a structure exhibiting metallic conductivity. It was suggested to form a complex selectively with carbon nanotubes.

  When acetic acid was added to the dispersion solution obtained in Example 7 and allowed to stand overnight, precipitation occurred. This is thought to be because carbon nanotubes could not be dispersed in the solvent and precipitated because the carbon nanotubes and porphyrin dimer derivative were separated by the addition of acetic acid. In addition, as shown in FIG. 3, the absorption of the visible ultraviolet absorption spectrum after the addition of acetic acid was reduced as a whole compared with that before the addition. From these results, it was revealed that only the carbon nanotubes can be easily isolated by adding acetic acid after the porphyrin dimer derivative of the present invention and the carbon nanotubes form a complex.

Porphylene phosphorus dimer derivatives, and a near infrared absorption spectrum of the complex of the porphyrin dimer and the carbon nanotubes to apply the present invention.

It is a Raman spectrum of the carbon nanotube which is not forming the composite_body | complex of the porphyrin dimer and carbon nanotube to which this invention is applied, and a composite_body | complex.

It is a visible ultraviolet absorption spectrum before and after acetic acid addition with respect to the composite_body | complex of the porphyrin dimer and carbon nanotube to which this invention is applied.

Claims (8)

The following chemical formula I

(In Formula I, m is 0 to 17)
Porphyrin dimer derivatives excluding paraporphyrin dimer derivatives represented by From at least one bromobenzaldehyde selected from 2-bromobenzaldehyde and 3-bromobenzaldehyde , 4-alkylbenzaldehyde (the alkyl group has 1 to 18 carbon atoms), and pyrrole, the following formula A

(In Formula A, m is 0 to 17)
A method for producing a porphyrin dimer derivative represented by the above chemical formula I, which comprises synthesizing the porphyrin derivative represented by formula (1) and subsequently reacting the porphyrin derivative with 9,9-dihexylfluorene-2,7-diboronic acid. A carbon nanotube composite in which a porphyrin dimer derivative, excluding the paraporphyrin dimer derivative , represented by the chemical formula I is bonded to a carbon nanotube. The following chemical formula II

(In Formula II, m is 0 to 17)
A carbon nanotube having a metallic conductivity characterized by being separated from a carbon nanotube composite to which a porphyrin dimer derivative represented by is bound. The following chemical formula III

(In Formula III, m is 0 to 17)
A carbon nanotube having a structure showing semiconducting conductivity, which is separated from a carbon nanotube composite to which a porphyrin dimer derivative represented by An acid selected from acetic acid, dilute hydrochloric acid aqueous solution, and dilute sulfuric acid aqueous solution is added to a dispersion liquid in which the carbon nanotube composite according to any one of claims 3, 4, and 5 is dispersed in an organic solvent to precipitate carbon nanotubes. A method for separating and purifying carbon nanotubes, comprising: A metallic material characterized in that an acid selected from acetic acid, dilute hydrochloric acid aqueous solution, and dilute sulfuric acid aqueous solution is added to a dispersion obtained by dispersing the carbon nanotube composite according to claim 4 in an organic solvent to precipitate carbon nanotubes. A method for separating and purifying carbon nanotubes having a conductive structure. 6. A semiconducting material characterized in that an acid selected from acetic acid, dilute hydrochloric acid aqueous solution, and dilute sulfuric acid aqueous solution is added to a dispersion obtained by dispersing the carbon nanotube composite according to claim 5 in an organic solvent to precipitate carbon nanotubes. A method for separating and purifying carbon nanotubes having a conductive structure.

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