THE INFRARED-SPECTRA OF COMPLEXES WITH PLANAR DITHIOOXAMIDES .9. CU(LH(2))(1)X(1) AND AG(LH(2))(1)X(1) COMPLEXES

In acid media Cu(I) and Ag(I) form complexes with planar dithiooxamide s (LH(2)) of formula M(LH(2))(1)X(1). Complexes with dithiooxamide (DT O), N-methyldithiooxamide (MDTO) and N,N'-dimethyldithiooxamide (DMTO) have been prepared. Although all complexes studied have the same form ula, different structures, depending on the halogen and the ligand use d, are formed, as is shown by a thorough study of the vibrational spec tra of these compounds. The M(DMDTO)(1)X(1) (X is Cl, Br) complexes an d Cu(MDTO)(1)Cl-1 are found to form binuclear complexes with bridging halogens, wherein the ligand exhibits an S-cis structure. For the othe r complexes studied, the dithiooxamide has an S-trans conformation and polymeric structures are formed. In the case of Ag(DTO)(1)Cl-1, Ag(MD TO)(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 pr esent in the structure, giving a tetrahedral coordination. For Cu(MDTO )(1)Br-1 two different types of complexes could be obtained.