Polymeric organosilicon systems XXIII. Synthesis and photochemical and thermal properties of ( E)- and ( Z)-poly[(disilanylene)ethenylenes

Abstract

( E)-Poly[(1,2-dimethyl-1,2-diphenyldisilanylene)ethenylene], ( E)-poly[(1,1,2,2-tetraphenyldisilanylene)ethenylene], ( E)-poly[(1,1,2,2-tetramethyldisilanylene)ethenylene], ( E)-poly[(1,2-dimethyl-1,2-diphenyldisilanylene)phenylethenylene], and ( Z)-poly[(1,2-dimethyl-1,2-diphenyldisilanylene)phenylethenylene] were prepared by the condensation reaction of the respective 1,2-bis(chlorosilyl)ethenes with sodium at 30°C under ultrasonic irradiation. Thermal behavior of the polymers was investigated by thermogravimetric analysis under a nitrogen atmosphere. The weight loss of the polymers at 1000°C was calculated to be 75–88% of the initial weights. Polymers thus obtained are photoactive and irradiation of thin solid films of the polymers in air resulted in the cleavage of the SiSi bonds in the polymer backbone, leading to the formation of SiOSi and SiOH bonds. The photolysis of the polymers in benzene gave the degradation products derived from homolytic scission of the SiSi bonds.