Single crystal EPR studies of the T 1 states of indene, indole, benzofuran and coumarin; systems with large | E|

Abstract

Single crystal EPR and phosphorescence studies of indene, indole, benzofuran and coumarin were made using DBB host. It was shown unambiguously that D < 3 | E| for these systems. ( Z axis is perpendicular to the molecular plane.) The directions of the magnetic axes were also determined. Spin densities at the 6 and 5 positions in indole were estimated and compared with those of other substituted benzenes. It is concluded that large spin density is located at the CC group.