Poly(di(ω-alkylphenyl)stannane)s
Choffat, Fabien ; Buchmüller, Yves ; Mensing, Christian ; Smith, Paul ; Caseri, Walter
In: Journal of Inorganic and Organometallic Polymers and Materials, 2009, vol. 19, no. 2, p. 166-175
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- Poly(di(ω-alkylphenyl)stannane)s, [Sn(C n H2n Ph)2] m with n=2-4, and a copolymer of di(3-propylphenyl)stannane and dibutylstannane of weight-average molar masses of 2-8·104g/mol were synthesized by dehydropolymerization of stannanes of the composition H2SnR2 using Wilkinson's catalyst [RhCl(PPh3)3]. At least two methylene groups were required as spacers between the phenyl group and the tin atom for polymerization to occur. The polystannanes were characterized by, among other techniques, 1H, 13C and 119Sn NMR spectroscopy, thermal analysis and X-ray diffraction. The polymers featured properties different from those of the corresponding poly(dialkylstannane)s. Specifically, the [Sn(C n H2n Ph)2] m family displayed glass transitions at remarkably low temperatures, down to ca. −50°C, and a lower value for a copolymer (−68°C). Polymers [Sn(CnH2nPh)2]m with n=2 and 3 and a copolymer at room temperature were of a gel-like concistence, which enabled facile orientation with shear forces. Finally, the temperature-dependent electrical conductivity was determined for poly(di(3-propylphenyl)stannane), which followed the law of typical semiconductors, with an activation energy for conduction of 0.12eV