SYNTHESIS AND REDUCTION OF THE 9,10-DISILAANTHRACENE DIMER

9,10-Dimethyl-9,10-disilaanthracene dimer (2) was prepared by treatmen t of 9,10-dihydro-9,10-disilaanthracene (1a) with 2 equiv of lithium. The reaction of 2 with excess lithium or potassium resulted in formati on, of 9,10-dilithio- or ,10-dipotassio-9,10-dimethyl-9,10-disilaanthr acene (4a,b), via the dianion 3, in which one Si-Si bond has been clea ved. On. treatment with alpha,omega-dichloropolysilanes, 4a was conver ted into the corresponding cyclic compounds 6-9, respectively.