Thermal, magnetic, FTIR and XRD study of new Co(II) and Ni(II) theophyllinato complexes with benzylamine or ethanolamine

• Published in: Journal of thermal analysis and calorimetry 1998, Vol.53 (2), p.343-354
• Main Authors: GAL, S, MADARASZ, J, FORIZS, E, LABADI, I, IZVEKOV, V, POKOL, G
• Format: Article
• Language: English
• Subjects: Chemistry; Coordination compounds; Dehydration; Diffraction patterns; Exact sciences and technology; Fourier transforms; Infrared spectra; Infrared spectroscopy; Inorganic chemistry and origins of life; Magnetic moments; Nickel compounds; Preparations and properties; Thermal stability; X-ray diffraction
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1023/A:1010177311508

Four new theophyllinato (th) complexes of Co(II) and Ni(II) were synthesized 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 structural information. The almost identical FTIR spectra and XRD patterns of Co and Ni compounds with same composition have indicated that Co(th)2(ba)2·2H2O (1) and Ni(th)2(ba)2·2H2O (2) or Co(th)2(ea)2 (3) and Ni(th)2(ea)2 (4) have very similar structure pair wise. The infrared spectra and X-ray diffraction patterns of thermally dehydrated 1 and 2containing benzylamine have allowed only to suggest that the co-ordination number around the metal centres is four, while the high thermal stability of complexes 3and 4have indicated that they contain two of bidentate ethanolamine molecules in octahedral co-ordination. A big difference observed between the magnetic moments of Co compounds 1and 3have proven that the inner co-ordination sphere of complexes with benzylamine (1and 2) is tetrahedral, whilst that with ethanolamine (3and 4) is basically octahedral, independent of the cation centres (Co or Ni).