SYNTHESIS, ABSORPTION CHARACTERISTICS AND SOME REACTIONS OF POLYGERMANES

A number of high molecular weight polygermanes were prepared by an improvement on Wurtz coupling reactions of dichlorogermanes and sodium metal, and by a method using diiodogermylene and Grignard reagents (or organolithiums). Most of the polygermanes thus prepared showed a narrow molecular distribution containing molecular weights 10(3)-10(4). In solution, the polygermanes showed characteristic electronic absorption bands at 300-350 nm and were strongly thermochromic for alkyl-substituted derivatives. Photolysis of the polygermanes proceeded by both contraction of the chain with loss of diorganogermylenes and homolytic scission of the germanium-germanium sigma bond.