LOW-TEMPERATURE REDETERMINATION OF THE STRUCTURES OF 3 GOLD COMPOUNDS

The structure of KAuCl4 (1), previously reported in the non-centrosymmetnc space group Pc, has been successfully redetermined in P2(1)/c; the gold atoms occupy centers of symmetry. The scatter of chemically equivalent bond lengths is greatly reduced and the precision of bond lengths and angles correspondingly improved. The structure of C13PAuCl (2), determined in 1962, has been redetermined to obtain more precise values for molecular dimensions; new values are Au-P 2.198, Au - Cl 2.279(2) angstrom. Short Au ... Au contacts (3.081 angstrom) connect the molecules in chains. The structure Of Ph3PSAuCl (3), for which a very long Au-Cl bond (2.555 angstrom) had been reported, was redetermined and gave a normal Au-Cl bond length of 2.265(2) angstrom; the previous value was probably a typing error. All redeterminations were carried out at -95-degrees-C.