MERCURY(II) HALIDE-COMPLEXES WITH CARBONYL AND THIOCARBONYL DONORS

Mercury(II) halides react with 2,6-dimethyl-4H-pyran-4-thione (DMTP) yielding complexes of general formulate [Hg(DMTP)2X2] and [Hg(DMTP)X2]n (X = Cl, Br or I), in which the ligand acts as a strong sulphur donor. With 2,6-dimethyl-4H-pyran-4-one (DMP) the complexes [Hg(DMP)X2]n and (HgX2)3(DMP)2 (X = Cl or Br) have been isolated, which easily release the weakly bound ligand molecules in common solvents. The compounds have been characterized by IR and NMR (H-1 and C-13) spectroscopy and by using thermogravimetric data. The adduct geometry is discussed on the basis of IR spectra, which suggest a tetrahedral arrangement for the 1:2 DMTP adducts. A halogen-bridged dimeric structure is proposed for the 1:1 DMTP adducts, whereas the [Hg(DMP)X2]n adducts are probably chain polymers with halide-mercury contacts. The (HgCl2)3(DMP)2 species should contain two types of mercury atoms with different coordination environments.