Preparation and X-ray characterization of two-coordinate Cu(I) complex of aliphatic thiolato ligand: Effect of steric bulk on coordination features

We have synthesized in a single-step procedure from available copper(I) precursor at RT two Cu(I) thiolato clusters of the formula [Cu4(μ-SCH(CH3)2)6]2− and [Cu5(μ-SC(CH3)3)6]− as revealed by X-ray crystallography, where increased steric bulk leads to a bigger cage with some two-coordinate metal centers. In addition, we identified a mononuclear two coordinate thiolato complex with the bulkier ligand, of the formula NEt4[Cu(SC(CH3)3)2]. This is only the second example of such a complex of an aliphatic ligand that is structurally characterized. The X-ray structure reveals an S–Cu–S angle of 176.7–179.5°, with Cu–S distances of 2.14 Å.

Graphical abstractCu(I) complexes of aliphatic thiolato ligands were prepared, where the steric bulk of the ligand impacts the coordination number and nuclearity. Whereas the isopropylthiolato ligand leads mainly to a Cu4S6 cluster where all Cu(I) centers are three coordinated, the tert-butylthiolato ligand leads under proper conditions to a mononuclear two-coordinate complex.Figure optionsDownload full-size imageDownload as PowerPoint slide