OXIDATIVELY INDUCED CARBON-CHAIN GROWTH AT A DITUNGSTEN CENTER

X-Ray structural and EHMO studies show that two electrons are sequenti ally removed from a W-W delta orbital on oxidation of the bis(metalla cyclopentadiene) complex [W-2(mu-C(4)Me(4))(2)(eta-C5H5)(2)] to [W-2(m u-C(4)Me(4))(2)(eta-C5H5)(2)](z+) (z = 1, 2); the dication undergoes C -C coupling and proton loss in boiling MeCN to give [W-2(mu-C(8)Me(7)C H(2))(eta-C5H5)(2)](+) which adds hydride ion to form the metallacyclo nonatetraene complex [W-2(mu-C(8)Me(8))(eta-C5H5)(2)].