POLYMERIC ORGANOSILICON SYSTEMS .18. SYNTHESIS AND PHOTOCHEMICAL PROPERTIES OF POLY[2,5-(DISILANYLENE) THIENYLENES]

Poly[2,5-(tetramethyldisilanylene)thienylene] (Ib), [2,5-(1,2-dimethyl diphenyldisilanylene)thienylene] (IIb) and -[1,2-di-methyldi(p-tolyl)d isilanylene]thienylene} (IIIb) were synthesized by sodium condensation reaction of the corresponding 2,5-bis(chlorosilyl)thienylenes in deca ne. Polymers Ib-IIIb reveal characteristic absorptions in the UV regio n. Irradiation of the thin films of Ib-IIIb in air led to disappearanc e of these absorptions. The photolysis of Ib-IIIb in a benzene solutio n resulted in homolytic scission of silicon-silicon bonds in the polym er backbone. In the photolysis of Ib, the cross-linking reaction occur red, while polymers IIb and IIIb afforded photodegradation products wi th low molecular weights.