Electronic States and Structure of Dibenzo[j,lm]-phenanthro[5,4,3-abcd]perylene

Abstract

Electronic absorption and emission, fluorescence anisotropy and linear dichroism techniques were applied to dibenzo [j, lm]phenanthro [5,4,3-abcd]perylene in order to determine its electronic structure and check the possibility of existence of conformational isomers. The results indicate the presence of only one conformer. Its structure is proposed on the basis of the experimental data as well as molecular mechanics and quantum chemical calculations.

Structural Changes Accompanying Intramolecular Electron Transfer: Focus on Twisted Intramolecular Charge-Transfer States and Structures

“…The difference in the behavior of the CT states of 198 (allowed emission) and 111 (forbidden transition), their excitonic states being of similar nature, seems to be in the symmetry restrictions in the state mixing that is operative for 111 . In view of the nonplanarity of numerous polycyclic arenes, among them perylene, − in 198 (C 1 ) there seems to be no symmetry restrictions at all. With respect to the ground-state conformation, 111 , with its very strong steric interaction of the two aryl systems, has an orthogonal conformation in S 0 ; 198 has a much weaker steric hindrance, like that of 1,1‘-binaphthyl.…”