365218-22-0Relevant academic research and scientific papers
Elongation of the π-system of phthalocyanines by introduction of thienyl substituents at the peripheral β positions. Synthesis and characterization
Muto,Temma,Kimura,Hanabusa,Shirai
, p. 6109 - 6115 (2001)
1,4,8,11,15,18,22,25-Octabutoxyphthalocyanines ((OBu)8Pcs) having eight 2-thienyl (1) and [2,2′-bithiophene]-5-yl (2) groups at β positions and their zinc(II) and cobalt(II) derivatives were prepared from 2-thienyl- (3) or [2,2′-bithiophene]-5-yl (4)-substituted phthalonitriles in moderate to good yields. The electronic absorption spectra of the Pcs showed red-shifted Q-bands relative to β-unsubstituted (OBu)8Pcs. The longer substituent, the [2,2′-bithiophene]-5-yl group, is more effective than the 2-thienyl group in enlarging the π-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 Pcs exhibit a remarkable color change from the original green color.
