Bis(alkylidynyl)tellurides and ditellurides

The tellurocarbonylates [M(CTe)(CO)2(Tp*)]− (M = Mo, W; obtained from [M(CBr)(CO)2(Tp*)] and Li2Te or [M(CLi)(CO)2(Tp*)] and Te) react with an additional equivalent of [M(CBr)(CO)2(Tp*)] to give bis(alkylidynyl)tellurides, [M2(μ-CTeC)(CO)4(Tp*)2], whilst oxidation with [Fe(η-C5H5)2]PF6 affords the corresponding ditellurides [M2(μ-CTe2C)(CO)4(Tp*)2]. The unprecedented MCTeCM and MCTe2CM bridges are discussed with reference to more conventional but rare alkylidynyltelluroethers [M(CTeR)(CO)2(Tp*)] (R = Me, nBu, Ph).