Synthesis, molecular structures, Mössbauer and electrochemical investigation of ferrocenyltelluride derivatives: (Fc2Te2)Fe(CO)3I2 [(CO)3IFe(μ-TeFc)]2, CpFe(CO)2TeFc, CpFe(CO)2TeX2Fc (X = Br, I) and CpFe(CO)2(μ-TeFc)Fe(CO)3I2

Depending on the ratio of the starting reagents, the interaction of [FcTeI] with Fe(CO)5 gave complex (Fc2Te2)Fe(CO)3I2 (1) bearing an Fc2Te2 ligand, or a dimeric complex [(CO)3IFe(μ-TeFc)]2 (2). An interaction of equimolar amounts of [CpFe(CO)2]2 and Fc2Te2 under the thermal conditions in toluene afforded CpFe(CO)2TeFc (3). Complex 3 can be easily halogenated at the Te center by elemental bromine and iodine to give monomeric CpFe(CO)2TeX2Fc (X = Br (4), I (5)). Complex 5 can be prepared alternatively via formal insertion of [FcTeI] into Fc–I bond of CpFe(CO)2I. Complex 3 readily substitutes one carbonyl in Fe(CO)4I2 to give the adduct CpFe(CO)2(μ-TeFc)Fe(CO)3I2 (6).