DIRECT EVIDENCE OF PHOTODISSOCIATION OF CARBAZOLE VIA THE HIGHER EXCITED TRIPLET STATE BY A DOUBLE EXCITATION METHOD

Abstract

Photodissociation of carbazole is investigated in cyclohexane at room temperature by a double excitation method which utilizes two successive excitation light pulses; the first flash L₁ is used to populate the lowest excited triplet state T₁ of carbazole and the second flash L₁ to excite T₁ into the higher excited triplet state T_n. Selective T_n←T₁ excitation of carbazole by L₂ brings about both the formation of carbazyl radical and the depletion of T₁. Therefore, it is concluded that carbazyl radical is formed via T_n.