PHOTODEGRADATION OF OLIGOMERIC POLYESTERS CONTAINING ANTHRAQUINONE AND 1,2-DIAMINE UNITS - SINGLE-ELECTRON TRANSFER INDUCED CATION-RADICAL BOND-CLEAVAGE IN THE SOLID-STATE

Oligomeric polyesters containing Light-absorbing anthraquinone electron acceptor chromophores and fragmentable 1,2-diamine donors have been synthesized. Irradiation with lambda > 340 nm in solution or as solid films results in photooxidative C-C bond cleavage of the 1,2-diamine units yielding essentially the same products in either case. The solid state photodegradation reaction was monitored using size exclusion chromatography and was found to be substantially less efficient than the corresponding solution reaction. This is attributed to an inefficient forward electron transfer step and the possibility of an induced reversibility of the fragmentation. The efficiency of photodegradation is suggested to be dependent on the donor/acceptor orientations in the solid state.