Electron-transfer and excited-state properties of radiolytically generated transients of acridine(1,8)dione dyes in an organic matrix

Abstract

Pulse radiolysis technique has been employed to generate and investigate electron and energy transfer reactions involving acridine(1,8)dione dyes in hydrocarbons. The transient absorption spectra obtained on pulse radiolysis of N₂-saturated solution in 1,2-dichloroethane are assigned to solute radical cation. The radical cations undergo charge transfer reaction with tetramethyl-p-phenylenediamine and triethyl amine. The transient absorption spectra in N₂-saturated solution in benzene are assigned to triplet-triplet absorption. It was observed that biphenyl, p-terphenyl and benzophenone triplets undergo energy transfer to methyl and phenyl substituted acridine(1,8)dione dyes generating the triplets of the acceptor. With H substituted acridine(1,8)dione dye, benzophenone and chloranil triplets favor electron-transfer followed by H⁺ transfer reaction forming benzophenone ketyl and chloranil semiquinone radicals respectively.