Secondary Interactions in Gold(I) Complexes with Thione Ligands. 2. Three Ionic Camphorsulfonates with Z’ = 2 [1]

All three structures of the form bis(thione)gold(I) camphor-10-sulfonate [thione = imidazolidine-2-thione, 1; 1-methyl-imidazolidine-2-thione, 2; thiazolidine-2-thione, 3] crystallize in chiral space groups with Z′ = 2; local inversion symmetry of the cationic assemblies (less pronounced for 3) provides some rationalisation for this. The basic structural units are accounted for in terms of classical hydrogen bonds, leading to rings involving ion pairs for 1 and 2, but to infinite chains of anions and cations for 3. Neighbouring ion pairs in 1 are joined by further classical hydrogen bonds, in 2 via interactions between parallel S-Au-S axes. Other interactions include Au···N for 1, Au···S and Au···O for 3, and weak hydrogen bonds C-H···O and C-H···S, especially between adjacent chains in 3. Each structure is divided into hydrophobic and hydrophilic regions.