Systematic Structure–Property Investigations on a Series of Alternating Carbazole–Thiophene Oligomers
摘要:
A series of alternating carbazole-thiophene oligomers, namely 2,7-linked carbazole-thiophene oligomers 1, 3, 5, 7, and 9 and 3,6-linked ones 2, 4, 6, 8, and 10, in which the molecular length was systematically elongated, were synthesized by Suzuki-Miyaura coupling reactions. The effects of the conjugation connectivity between the carbazole and thiophene moieties and the molecular length on the electronic, photophysical, and electrochemical properties of 1-10 were comprehensively investigated. In the present oligomer architectures, the connection with thiophene at the 2,7-positions of carbazole ensures pi-conjugation to a high extent and high fluorescence quantum yields, while that at the 3,6-positions enhances the donor ability. The increase in the molecular length of the 2,7-linked oligomers effectively extends pi-conjugation. The relationship between structural variations and photophysical properties was examined by fluorescence lifetime measurements in detail. The X-ray crystal structure of 6 was also disclosed.
Selective synthesis of trisubstituted (trifluoromethyl)alkenes via ligand-free Cu-catalyzed syn hydroarylation, hydroalkenylation and hydroallylation of (trifluoromethyl)alkynes
作者:Y. Yamamoto、E. Ohkubo、M. Shibuya
DOI:10.1039/c6gc01782g
日期:——
In the presence of catalytic amounts of Cu(OAc)2, the hydroarylation of (trifluoromethyl)alkynes with arylboronic acids proceeded in MeOH at 28 [degree]C to afford diverse [small beta]-(trifluoromethyl)styrenes. Moreover, the hydroalkenylation and hydroallylation...