OPTICAL-SPECTRA OF RADICAL-ION PRODUCTS OF PULSE-RADIOLYSIS OF 10-ETHOXY-10-METHYL-10-SIL-9-OXAROPHENANTHRENE

Optical absorption spectra of transient charged species in liquid 10-e thoxy-10-methyl-10-sil-9-oxarophenanthrene (EMSORP) and its solutions (2 x 10(-2) mol/l) in methylcyclohexane, chloroform, dipropylamine, an d deuterated ammonia were measured using a pulse radiolysis technique. Absorption bands at 403 and 630 nm for the EMSORP radical anion and t hose for the monomeric (390 and 580 nm) and dimeric (830 and 1900 nm) radical cations were characterized. It was found that the spectra of t he monomeric radical ions correspond to the spectra of similar species in biphenyl solutions. This correspondence is not due to fragmentatio n of the primary radical ion but perturbation of the phenanthrene mole cule conjugation by the siloxane group. The effect of conformation of diaryl compounds on the position of the charge-resonance band of the d imeric radical cations was revealed. The bonding energy between the co nstituents of the ENSORP dimeric radical cations was estimated as 0.33 eV.