ESR STUDY OF CU(II)-INDOMETHACIN AND ITS PYRIDINE AND DMF ADDUCTS

Powder ESR spectra of [Cu2(Ind)4](H2O)2 at room temperature show the presence of copper acetate like dimers characterized by a strong antiferromagnetic exchange interaction (J almost-equal-to -338 cm-1). Two different monomeric species were evidenced in 40%Py+60%DMF solution absorbed on NaY zeolite: the Cu(Ind)2(DMF)2 with an elongated tetragonal-octahedral symmetry and the Cu(Ind)2(Py)2 with a CuN2O2 chromophore in a trans square-planar arrangement. Only one monomeric species Cu(Ind)2(Py)2 was identified in 20%Py+80%DMF and 20%Py+80%Chloroform solutions. The Cu(Py)42+ species of CuN4 chromophore occurs in pyridine Cu(II)-indomethacin solution suggesting a decomposition of the solvit compound.