Step-by-step transformations of ferrocenyltellurium complexes of Group VIB metal carbonyls

Stepwise interactions of photochemically generated M(CO)5(THF) (M = Cr, Mo, W) with diferrocenylditelluride initially generated mononuclear M(CO)5(Fc2Te2) followed by the bimetallic [M(CO)5]2(μ-Fc2Te2), with terminal and bridged Fc2Te2 moieties, respectively. On photolysis, [M(CO)5]2(μ-Fc2Te2) transformed to FcTe bridged and M–M bonded “butterfly” complexes [(CO)4M(μ-FcTe)]2 via the elimination of two carbonyl groups. The solid state structures and 125Te NMR spectral data of the new complexes and a new polymorphic form of Fc2Te2 having remarkable intermolecular Te⋯π-Cp short contacts (av. 3.5 Å) are discussed.