Dipyrido[3,2-a:2',3'-c]phenazine-based donor-acceptor aromatic heterocyclic compounds with thienyl and triphenylamino chromophores at the 2,7- and/or 10,13-positions.
A series of T- and H-shaped donor-acceptor (D-A) types of dipyrido[3,2-a:2',3'-c]phenazine (DPPZ)-based molecules, extended by thienyl and triphenylamino chromophores at the 2,7-(bottom) and/or 10,13-positions (top), have been designed and prepared successfully. Synthetic, structural, thermal, spectral, and computational comparisons have been carried out for related compounds because of their adjustable intramolecular charge-transfer properties. It is noted that a pair of structural isomers (5 and 6) has been obtained, respectively, where distinguishable UV/Vis and fluorescence spectra, electrochemical activity, thermal stability, and bandgaps are observed. Furthermore, compounds 6, 8, 10, 11, 13, and 15 exhibit excellent thermal stability, and the Td10 values for them are found to range from 524 to 646 °C, which can be regarded as one of the best groups of thermally stable compounds among organic small molecules. In addition, theoretical calculations were performed, and the structure-property relationships were examined to reveal the effects of the position and number of donor arms on the DPPZ acceptor core.
State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructures Laboratory, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (P.R. China), Fax: (+86) 2583314502.
Xiao-Xu
XX
Wang
Tao
T
Tao
Jiao
J
Geng
Bin-Bin
BB
Ma
Yu-Xin
YX
Peng
Wei
W
Huang
chromophores; donor-acceptor systems; fluorescence; isomers; thermal stability