Implications of the results of a routine structure determination: Tris(triphenylphosphine)gold(I) chloride bis(dichloromethane)

Tris(triphenylphosphine)gold(I) chloride was found to form a crystalline phase with two molecules of dichloromethane. In the crystal the chlorine atom is almost fully dissociated from the [(Ph₃P)₃Au]⁺ cation. The gold atom shows only a minor displacement from the plane of the phosphorus atoms (sum of the angles P-Au-P 355.35°; d(Au-Cl) 2.7962(6) Å), very similar to the geometry of the solvent-free crystalline phase. The results are discussed in the context of all known structures for compounds [(Ph₃P)₃MCl], M = Cu, Ag, Au. The variations in structure appear to be dominated by electronic (relativistic) rather than steric effects.