Spectroscopic studies of azides and nitrenes derived from anthracene

Abstract

Results of spectroscopic investigations on azides and nitrenes derived from anthracene are reported. The following techniques were used: optical absorption of glassy solutions at low temperatures, polarized optical absorption of stretched polymer films at low temperatures, electron spin resonance of frozen random solutions and electron spin resonance of samples partially oriented by photolysis with polarized light (magnetophotoselection). Experimental results are briefly discussed in the light of current ideas on the electronic structure of azides and nitrenes. The azido group interacts weakly with the anthracene chromophore, leading to a red shift of the L_a band. For nitrenes, we verify the usual correlation between extent of delocalisation in the π system and the value of the zero field splitting parameter. The average hyperfine coupling constant with nitrogen follows the same trend.