Chloro(tetrahydrothiophene)gold(I)  Chloro(tetrahydrothiophene)gold(I), abbreviated (tht)AuCl, is a coordination complex of gold. Like the dimethyl sulfide analog, this compound is used as a convenient entry point to gold chemistry. The tetrahydrothiophene ligand is labile and is readily substituted with other stronger ligands. This compound is not commonly available commercially. It may be prepared by the reaction of tetrachloroauric acid with tetrahydrothiophene:  The complex adopts a linear coordination geometry, which is typical of most gold(I) compounds. It crystallizes in the orthorhombic space group "Pmc"21 with a = 6.540(1) Å, b = 8.192(1) Å, c = 12.794(3) Å with Z = 4 formula units per unit cell. The bromide congener is isostructural. It is somewhat less thermally labile compared to (Me2S)AuCl, but is still sensitive to temperature and light.