Thermal analysis of M(LH2)2X2 complexes with planar dithio oxamides M = Pt, Pd, Ni; X = Cl, Br, I.
作者:H. Hofmans、H.O. Desseyn
DOI:10.1016/0040-6031(85)85531-3
日期:1985.4
Abstract In this study we compared the thermal decompositions and the presence of stable intermediates for M(LH2)2X2complexes with LH2 is a planar dithio-oxamide and X = Cl, Br, I. The difference in thermal decomposition can be explained with the H.S.A.B. theory.
In acid media Cu(I) and Ag(I) form complexes with planar dithiooxamides (LH(2)) of formula M(LH(2))(1)X(1). Complexes with dithiooxamide (DTO), N-methyldithiooxamide (MDTO) and N,N'-dimethyldithiooxamide (DMTO) have been prepared. Although all complexes studied have the same formula, different structures, depending on the halogen and the ligand used, are formed, as is shown by a thorough study of the vibrational spectra of these compounds. The M(DMDTO)(1)X(1) (X is Cl, Br) complexes and Cu(MDTO)(1)Cl-1 are found to form binuclear complexes with bridging halogens, wherein the ligand exhibits an S-cis structure. For the other complexes studied, the dithiooxamide has an S-trans conformation and polymeric structures are formed. In the case of Ag(DTO)(1)Cl-1, Ag(MDTO)(1)Cl-1 and Cu(DTO)(1)Cl-1 terminal metal-halogen bonds are present and trigonal coordination around the metal is proposed, while for Cu(DTO)(1)Br-1 and the Cu(LH(2))(1)I-1 complexes bridging halogens are present in the structure, giving a tetrahedral coordination. For Cu(MDTO)(1)Br-1 two different types of complexes could be obtained.
The infrared spectra of complexes with planar dithio-oxamides—VII. The Cu(LH2)1X2 and Cu(LH2)2X2 complexes