Hg(II) complexes have been prepared with γ-mercaptoamine ligands 1-methyl-4-mercaptopiperidine (4-MP), 1-methyl-3(mercaptomethyl)piperidine (3-MMP) and 1-methyl-2(2-mercaptoethyl)piperidine (2-MEP) with 1:1 and 1:2 metal to ligand ratios. Infrared and Raman spectra for all these compounds have been recorded and discussed. The spectral features agree with a linear SHgS structure and with the characteristic two-coordination of mercury in all the complexes. The structure of [Hg(4-MP)2](ClO4)2 has been determined by X-ray crystallography. The crystals are orthorhombic, space group C2221 (Z=4) in a unit cell of dimensions a= 13.161 (3) Å, b= 6.589 (2) Å and c= 24.740 (4) Å. Solution of the structure by direct methods led to a final weighted R factor of 0.057 for 1339 independent reflections. The crystal structure consists of discrete [Hg(4-MP)2]2+ cations and ClO4- anions packed in layers paralell to the (100) plane. © 1982.