214403-19-7Relevant articles and documents
Catalytic synthesis of poly(arylmethylgermanes) by demethanative coupling: A mild route to σ-conjugated polymers
Katz, Sandra M.,Reichl, Jennifer A.,Berry, Donald H.
, p. 9844 - 9849 (2007/10/03)
A variety of poly(arylmethylgermanes) have been synthesized from aryldimethylgermanes in high yield via mild catalytic demethanative coupling using tetrakis(trimethylphosphine)dimethylruthenium as a convenient catalyst precursor. Polymerizations of germanes Me2GeArH (At = phenyl, p-tolyl, p- fluoro, p-trifluorotolyl, p-anisyl, and m-xylyl) proceed in neat monomer at room temperature. Catalyst removal can be effected by treatment of the reaction mixture with air, which gives polymer yields between 70% and 100%. Alternatively, separation of the catalyst by precipitation of the polymers from THF solution with methanol gives lower yields, but of somewhat higher molecular weight material. The new polygermanes are characterized by 1H NMR and by gel permeation chromatography (GPC) using both polystyrene standards and light scattering methods. Molecular weights calculated by polystyrene analysis fall in the ranges of M(w) = 3 x 103 to 7 x 103 and M(n) = 2 x 103 to 6 x 103. Values obtained from light scattering are approximately 60% and 82% higher, respectively, resulting in M(w) measured by SEC/LS in the range 5 x 103 to 1 x 104, with M(w)/M(n) ~ 1.3. The absorption spectra of the polygermanes exhibit λ(max) in the range 326-338 nm. Comparison of the properties of poly(phenylmethylgermane) prepared by catalytic demethanative coupling and Wurtz coupling of MePhGeCl2 with sodium revealed no significant differences.
