Synthesis, crystal structure, and thermal behavior of dimethylgold(III) acetate

Abstract

A dimethylgold(III) compound with an acetate fragment [(CH3)2AuOCOCH3]2 has been synthesized. The complex was identified from the melting point, IR, 1H NMR, and mass spectrometry data. The temperature dependence of saturated vapor pressure over crystals has been measured and the thermodynamic parameters of sublimation have been determined by Knudsen’s effusion method with mass spectrometric measurements of the composition of the gas phase: ΔH subl = 100.87 kJ·mol−1, ΔS subl = 216.67 J·mol−1·K−1. The thermal behavior of the solid compound was investigated by differential thermal analysis. The compound was studied by X-ray diffraction. Crystal data for C8H18Au2O4: a = 12.214(5) A, b = 14.307(3) A, c = 7.6635(15) A; β = 103.39(3)°, Z = 4, d calc = 2.917 g/cm3, space group P2(1)/c, R = 0.0261. The [(CH3)2AuOCOCH3]2 dimer complex with an Au...Au distance of 2.989 A is the structural unit. The gold atom has a square plane environment of two carbon and two oxygen atoms; the Au-O distances vary from 2.118 A to 2.139 A. The molecules are arranged in chains linked by van der Waals interactions.