SYNTHESIS AND CHARACTERIZATION OF DICHLORO AND DIBROMO(2-(DIMETHYLAMINOMETHYL)THIOPHENE) COPPER(II) COMPLEXES

The 2-(dimethylaminomethyl)thiophene (dmamt) complexes with copper(II) chloride and bromide were prepared and characterized by optical, EPR, XPS spectroscopies and magnetic susceptibility measurements. The low- energy absorption band above 850 nm and the relatively small EPR hyper fine coupling constant (A//congruent-to 125 G) indicate the pseudotetr ahedral site symmetry around copper(II) ion both in Cu(dmamt)Cl2 and C u(dmamt)Br2 complexes. The higher satellite to main peak intensity of Cu 2P3/2 core electron binding energy in XPS spectra also supports the pseudotetrahedral geometry around the copper(II) ions having CuNSX2 c hromophores. The distortion from square-planar to pseudotetrahedral sy mmetry is likely to arise from the steric hindrance of the bulky dmamt ligand in the complex. Magnetic susceptibility study shows that these compounds follow Curie-Weiss law in the temperature range of 77-300 K with positive Weiss constant exhibiting the ferromagnetic interaction between copper(II) ions in solid state.