X-ray diffraction study of volatile complexes of dimethylgold(III) derived from symmetrical β-diketones

Crystal chemical investigation of volatile dimethylgold(III) β-diketonates of the general formula (CH₃)₂AuL [L = acetylacetone (acac), dipivalylmethane (dpm), dibenzoylmethane (dbm)] has been carried out for the first time. The synthetic procedure and structural data are reported; differential thermal analysis (DTA) data are given. The structure of the compounds includes monomeric complex molecules arranged as polymeric stack associates. The gold atom has a plane square environment AuO₂C₂ formed by two oxygen atoms of the bidentate (O,O) ligand and two methyl groups. The geometrical characteristics of the coordination units are the following: in all complexes, the Au-O and Au-C_Me bond lengths and O-Au-O chelate angles are 2.070–2.108 Å, 1.989–2.034 Å, and 89.7-93.7°, respectively. The shortest Au-Au distance (3.475 Å) in the stack is observed for the (CH₃)₂Au(dpm) complex.