Elongation of the π-System of Phthalocyanines by Introduction of Thienyl Substituents at the Peripheral β Positions. Synthesis and Characterization
摘要:
1,4,8,11,15,18,22,25-Octabutoxyphthalocyanines ((OBu)(8)Pcs) having eight 2-thienyl (1) and [2,2 ' -bithiophene] -5-yl (2) groups at beta positions and their zinc(II) and cobalt(II) derivatives were prepared from 2-thienyl- (3) or [2,2 ' -bithiophenel-5-yl (4)-substituted phthalonitriles in moderate to good yields. The electronic absorption spectra of the Pes showed red-shifted Q-bands relative to P-unsubstituted (OBu)8Pcs. The longer substituent, the [2,2 ' -bithiophene]-5-yl group, is more effective than the 2-thienyl group in enlarging the a-conjugated system of the Pcs. The ring oxidation potential obtained by cyclic voltammetry shifted cathodically with increasing chain length, indicating destabilization of the HOMOs. Due to the shift of the Q-band, 2-thienyl- and [2,2 ' -bithiophene]-5-yl-substituted Pes exhibit a remarkable color change from the original green color.
Elongation of the π-System of Phthalocyanines by Introduction of Thienyl Substituents at the Peripheral β Positions. Synthesis and Characterization
摘要:
1,4,8,11,15,18,22,25-Octabutoxyphthalocyanines ((OBu)(8)Pcs) having eight 2-thienyl (1) and [2,2 ' -bithiophene] -5-yl (2) groups at beta positions and their zinc(II) and cobalt(II) derivatives were prepared from 2-thienyl- (3) or [2,2 ' -bithiophenel-5-yl (4)-substituted phthalonitriles in moderate to good yields. The electronic absorption spectra of the Pes showed red-shifted Q-bands relative to P-unsubstituted (OBu)8Pcs. The longer substituent, the [2,2 ' -bithiophene]-5-yl group, is more effective than the 2-thienyl group in enlarging the a-conjugated system of the Pcs. The ring oxidation potential obtained by cyclic voltammetry shifted cathodically with increasing chain length, indicating destabilization of the HOMOs. Due to the shift of the Q-band, 2-thienyl- and [2,2 ' -bithiophene]-5-yl-substituted Pes exhibit a remarkable color change from the original green color.
Elongation of the π-System of Phthalocyanines by Introduction of Thienyl Substituents at the Peripheral <i>β</i> Positions. Synthesis and Characterization
1,4,8,11,15,18,22,25-Octabutoxyphthalocyanines ((OBu)(8)Pcs) having eight 2-thienyl (1) and [2,2 ' -bithiophene] -5-yl (2) groups at beta positions and their zinc(II) and cobalt(II) derivatives were prepared from 2-thienyl- (3) or [2,2 ' -bithiophenel-5-yl (4)-substituted phthalonitriles in moderate to good yields. The electronic absorption spectra of the Pes showed red-shifted Q-bands relative to P-unsubstituted (OBu)8Pcs. The longer substituent, the [2,2 ' -bithiophene]-5-yl group, is more effective than the 2-thienyl group in enlarging the a-conjugated system of the Pcs. The ring oxidation potential obtained by cyclic voltammetry shifted cathodically with increasing chain length, indicating destabilization of the HOMOs. Due to the shift of the Q-band, 2-thienyl- and [2,2 ' -bithiophene]-5-yl-substituted Pes exhibit a remarkable color change from the original green color.