Synthesis and Characterization of N‐(o‐Vanillinidene)‐p‐anisidine and N,N′‐bis(o‐Vanillinidene)ethylenediamine and Their Metal Complexes

Abstract

Two Schiff bases, N‐(o‐vanillinidene)‐p‐anisidine (o‐VPAH) and N,N′‐bis(o‐vanillinidene)ethylenediamine (o‐VEDH₂), and eleven complexes of the compositions [M(L)(OAc)(H₂O)] {where M = Cu(II) (1), Co(II) (2), Mn(II) (3) or Ni(II) (4) and OAcH = CH₃COOH}, [Zn(L)₂]·H₂O (5), [M(L′)(H₂O)₂] {where M = Cu(II) (6) or Ni(II) (7)}, [Zn(L′)]·2H₂O (8), [Sm(L′)(OAc)(H₂O)] (9), [Th(L′)(NO₃)₂] (10) and [UO₂(L′)(H₂O)]·H₂O (11) (where LH = o‐VPAH, and L′H₂ = o‐VEDH₂), were prepared. From the elemental analyses, IR, electronic and NMR spectra, magnetic susceptibility measurements and thermal studies, the mode of chelation of the ligands and geometry of the complex molecules were assigned. In all of the complexes, o‐VPAH acts as a monobasic‐bidentate ligand and o‐VEDH₂ acts as a dibasic‐tetradentate ligand. The presence of water is revealed by thermograms and supported by the presence of relevant bands in their IR spectra. Suitable structures have been proposed for these complexes.

Keywords:

• N‐(o‐vanillinidene)‐p‐anisidine
• N,N'‐bis(o‐vanillinidene)‐ethylenediamine
• Cu(II)
• Co(II)
• Mn(II)
• Ni(II)
• Zn(II)
• Sm(III)
• Th(IV)
• UO₂ (VI) complexes

Acknowledgments

The authors are thankful to Professor S. D. Tripathi, Vice‐Chancellor of this University, for encouragement, and Professor K. K. Mishra, Head, Department of Chemistry, for laboratory facilities and helpful discussions. Analytical facilities provided by the Central Drug Research Institute, Lucknow, India, and the Regional Sophisticated Instrumentation Centre, Indian Institute of Technology, Chennai, India, are gratefully acknowledged.