Bis(alkylidynyl)tellurides and ditellurides

The tellurocarbonylates [M(CTe)(CO) 2 (Tp*)] - (M = Mo, W; obtained from [M([triple bond, length as m-dash]CBr)(CO) 2 (Tp*)] and Li 2 Te or [M([triple bond, length as m-dash]CLi)(CO) 2 (Tp*)] and Te) react with an additional equivalent of [M([triple bond, length as m-dash]CBr)(CO) 2 (Tp*)] to give bis(alkylidynyl)tellurides, [M 2 (μ-CTeC)(CO) 4 (Tp*) 2 ], whilst oxidation with [Fe(η-C 5 H 5 ) 2 ]PF 6 affords the corresponding ditellurides [M 2 (μ-CTe 2 C)(CO) 4 (Tp*) 2 ]. The unprecedented M[triple bond, length as m-dash]CTeC[triple bond, length as m-dash]M and M[triple bond, length as m-dash]CTe 2 C[triple bond, length as m-dash]M bridges are discussed with reference to more conventional but rare alkylidynyltelluroethers [M([triple bond, length as m-dash]CTeR)(CO) 2 (Tp*)] (R = Me, n Bu, Ph).