| Abstract: | Poly5, 5′ - (dimethylsilylene) - 2, 2′ - dithienylene] (4a), poly5, 5′ -(methylphenylsilylene)-2, 2′ -dithienylene] (4b), poly5, 5′ -(1, 1, 2, 2-tetramethyldisilanylene)-2, 2′ -dithienylene] (4c), poly5, 5′-(1, 2-dimethyl-1, 2-diphenyldisilanylene)-2, 2′ -dithienylene] (4d), poly5, 5′-(1, 2, 2, 2-tetramethyldisilanylene)-2, 2′-dithienylene] (4e), and poly5, 5′-(1, 1, 2, 2, 3, 3 - hexamethyltrisilanylene) - 2, 2′ -dithienylene] were synthesized by dehalogenative coupling of the respective bis(2-bromothienyl)- substituted mono, di- and tri-silanes with magnesium in the presence of a catalytic amount of a nickel(II) complex in 16–99% yields. The polymers thus obtained are light-yellow solids and soluble in common organic solvents. Molecular weights, Mw, of the polymers were measured and found to be 7800–35 000 by gel-permeation chromatography relative to polystyrene standards. The photochemical properties of the polymers (4a–4d) having silylene and disilanylene units were investigated. Only poly5, 5′-(1, 2-dimethyl-1, 2-diphenyl-disilanylene)-2, 2′-dithienylene] (4d) was found to be photoactive, but the others were inactive. When the thin solid films prepared from the polymers 4a–4e by spin-coating were exposed to antimony(V) fluoride in vacuo, the films became conducting; their conductivities were determined to be 10?2 – 10?3 S cm?1 by the four-probe method. |
