Decamethylzirconocene-chalcogenide-hydride complexes

Stoichiometric reaction of [(C5Me5)(2)ZrH8]Li (1) with diphenylphosphine su lfide or selenide yields the bimetallic species [(C5Me5)(2)ZrH](2)(mu-E) (E = S 2, Se 3). These reactions are proposed to proceed via an intermediate of the form [(C5Me5)(2)ZrH2(EPPh2)](-) with concurrent loss of dihydrogen. Subsequent p-elimination of Ph2PH affords 2 and 3 via dimerization and loss of Li2E. The initial synthetic strategy to trap an anionic intermediate in volved treatment of 1 with diphenylphosphine oxide. This approach failed, a ffording instead the tetrameric species [Ph2POLi(THF)](4) (4) and Cp*2ZrH2. An alternative, successful approach to an oxide anion involved the reactio n of 1 with Me3NO. The resulting species [(C5Me5)(2)ZrH(OLi(THF))](2) (5) w as isolated, and the species 2-5 have been structurally characterized. Thes e results are presented and the implications discussed.