Reactivity of [(Cp*CoPh)(Cp*Co)(μ-TePh)(μ-k²-Te,H-TeBH₃)] Toward [<i>M</i>(CO)₅·THF] (<i>M</i> = Mo and W), CS₂, and [Fe₂(CO)₉]

Syntheses and structural elucidation of homo- and heterochalcogen-bridged complexes of cobalt are described. The photolytic reaction of bimetallic hydridoborate species [(Cp*CoPh)(Cp*Co)(μ-TePh)(μ-k²-Te,H-TeBH₃)] (<b>1</b>) in the presence of [<i>M</i>(CO)₅·THF] (<i>M</i> = Mo and W) afforded unprecedented tellurolate-bridged [(Cp*Co)₂(μ-TePh)₃]⁺[TePh{<i>M</i>(CO)₅}₂]^- (<i>M</i> = Mo (<b>2</b>), W (<b>3</b>)) as ionic complexes with the release of BH₃. Complex <b>2</b> has three bridged-TePh moieties between two Cp*Co fragments in the cation part, whereas the anionic part, [TePh{<i>M</i>(CO)₅}₂]^-, shows a distorted trigonal pyramidal core. In order to synthesize mixed chalcogenate-bridged complexes having both S and Te, we carried out the photolytic reaction of <b>1</b> with CS₂. Although the objective of generating mixed chalcogen-bridged complex [(Cp*Co)₂(μ-TePh)₂(μ-S)] was not achieved, the reaction yielded an unusual bimetallic thiotellurite complex [(Cp*Co)₂(μ-S₃TeS₃-κ²S:κ²Te:κ²S')] (<b>4</b>). Complex <b>4</b> has two wings, each consisting of three sulfur atoms, that are connected to two Co-atoms and one Te-atom. Further, to synthesize the Fe analogue of <b>2</b> and <b>3</b>, a similar reaction was carried out with [Fe₂(CO)₉]. However, the reaction led to the formation of the trimetallic complex [Cp*Co(CO)(μ₃-Te)₂{Fe₂(CO)₆}] (<b>5</b>). These complexes were characterized by employing different multinuclear NMR, IR spectroscopies, single-crystal X-ray diffraction analyses, and mass spectrometry. Additionally, computational analyses of these chalcogen-bridged neutral and ionic complexes were conducted to offer insight into their bonding.