Reductive selenidation of [Cp*MoO2Cl]: Synthesis, structure and bonding in new binuclear and trinuclear clusters

•Reaction of [Cp*MoO2Cl] with H2Se gives selenium clusters.•Binuclear and trinuclear complexes were isolated.•Binuclear cluster contains two unprecedented Se34− ligands.•Characterized with X-ray, 77Se, 1H NMR, ESI–MS and DFT calculations.

The reaction between in situ generated H2Se and [Cp*MoO2Cl] (1) produces a mixture of binuclear and trinuclear selenium clusters. New selenide complex [Cp*2Mo2Se6] (2) was isolated from CH2Cl2 extracts of the products mixture and characterized by X-ray analysis. This binuclear cluster contains two unprecedented Se34− ligands isoelectronic to I3−. Column chromatography of extracts in air produced two bands, from which [Cp*2Mo2O2Se2] (3) and a new triangular cluster [Cp*3Mo3Se4][ZnCl3(H2O)] (4) were isolated and structurally characterized. The products were characterized by 1H and 77Se NMR, ESI–MS, IR and elemental analysis. Quantum-chemical calculations were used to analyze the Mo–Mo bonding and to help identify lines in 77Se NMR spectra. Crystal and molecular structure of starting [Cp*MoO2Cl] was also determined.

Graphical abstractThe reaction between in situ generated H2Se and [Cp*MoO2Cl] produces a mixture of [Cp*2Mo2Se6], [Cp*2Mo2O2Se2] and [Cp*3Mo3Se4][ZnCl3(H2O)] clusters. Under these conditions, hydrogen selenide may act as source of both selenide (Se2−) and diselenide (Se22−) ligands.Figure optionsDownload full-size imageDownload as PowerPoint slide