THERMAL, MAGNETIC, FTIR AND XRD STUDY OF NEW CO(II) AND NI(II) THEOPHYLLINATO COMPLEXES WITH BENZYLAMINE OR ETHANOLAMINE

Four new theophyllinato (th) complexes of Co(II) and Ni(II) were synth esized containing ethanolamine (2-aminoethanol, ea) or benzylamine (ba ). Comprehensive FTIR spectroscopic, powder XRD, magnetic and thermal studies on these mixed ligand complexes have been carried out to get s tructural information. The almost identical FTIR spectra and XRD patte rns of Co and Ni compounds with same composition have indicated that C o(th)(2)(ba)(2). 2H(2)O (1) and Ni(th)(2)(ba)(2). 2H(2)O (2) or Co(th) (2)(ea)(2) (3) and Ni(th)(2)(ea)(2) (4) have very similar structure pa ir wise. The infrared spectra and X-ray diffraction patterns of therma lly dehydrated a and 2 containing benzylamine have allowed only to sug gest that the co-ordination number around the metal centres is four, w hile the high thermal stability of complexes 3 and 4 have indicated th at they contain two of bidentate ethanolamine molecules in octahedral co-ordination. A big difference observed between the magnetic moments of Co compounds 1 and 3 have proven that the inner co-ordination spher e of complexes with benzylamine (1 and 2) is tetrahedral, whilst that with ethanolamine (3 and 4) is basically octahedral, independent of th e cation centres (Co or Ni).