Tetraphenylphosphonium bis(2-thioxo-1,3-dithiole-4,5-dithiolato)aurate(III) acetone solvate and ethyltriphenylphosphonium bis(2-thioxo-1,3-dithiole-4,5-dithiolato)aurate(III).

In the two title complexes, (C24H20P)[Au(C3S5)2] x C3H6O, (I), and (C20H20P)[Au(C3S5)2], (II), the Au(III) atoms exhibit square-planar coordinations involving four S atoms from two 2-thioxo-1,3-dithiole-4,5-dithiolate (dmit) ligands. The Au-S bond lengths, ranging from 2.3057 (8) to 2.3233 (7) A in (I) and from 2.3119 (8) to 2.3291 (10) A in (II), are slightly smaller than the sum of the single-bond covalent radii. In (I), there are two halves of independent Ph4P+ cations, in which the two P atoms lie on twofold rotation axis sites. The Ph4P+ cations and [Au(C3S5)2]- anions are interspersed as columns in the packing. Layers composed of Ph4P+ and [Au(C3S5)2]- are separated by layers of acetone molecules. In (II), the [Au(C3S5)2]- anions and EtPh3P+ counter-cations form a layered arrangement, and the [Au(C3S5)2]- anions form discrete pairs with a long intermolecular Au...S interaction for each Au atom in the crystal structure.