Journal of Thermal Analysis and Calorimetry

, Volume 107, Issue 1, pp 97–103 | Cite as

Synthetic, spectroscopic and thermal studies of some complexes of unsymmetrical Schiff base ligand

  • Gaurav Pethe
  • Amit Yaul
  • Anand Aswar


New unsymmetrical Schiff base ligand (H2L) is prepared via condensation of 2-hydroxy-5-methyl acetophenone, 2-hydroxy-5-chloro-3-nitro acetophenone and carbohydrazide in 1:1:1 ratio. Metal complexes of VO(IV), Cr(III), Mn(III), Fe(III), Zr(IV), MoO2(VI), WO2(VI) and UO2(VI) have been prepared. These complexes were characterized by elemental analysis, UV–Vis and IR spectroscopy and magnetic moment and thermogravimetric analysis. The purity of the ligand and the metal complexes is confirmed by microanalyses, while unsymmetrical nature of ligand was further corroborated by 1H NMR. All the complexes are air stable and insoluble in water and common organic solvents but fairly soluble in DMSO. The elemental analysis shows 1:1 metal to ligand stoichiometry for all the complexes. Thermal behaviour of the complexes was studied, the complexes were found to be quite stable and their thermal decomposition was generally via partially loss of the organic moiety and ended with respective metal oxide as a final product. Comparison of the IR spectrum of ligand and its metal complexes confirm that Schiff base behave as a dibasic tetradentate ligand towards the central metal ion with an ONNO donor sequence. The dc electrical conductivity is studied and data obtained obeyed the relation σ = σ 0 exp(−E a/kT) over the temperature range 40–130 °C. X-ray diffraction study of VO(IV) complex shows its crystalline nature with triclinic crystal system.


Unsymmetrical Schiff base Metal complexes Thermal analysis dc Conductivity 



The authors wish to thank SAIF Chandigarh and CDRI Lucknow for recording elemental analyses, IR, NMR and electronic spectral analysis of the compounds. One of the authors (ARY) is thankful to University Grants Commission for providing financial assistance.


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Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2011

Authors and Affiliations

  1. 1.Department of ChemistrySant Gadge Baba Amravati UniversityAmravatiIndia

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