Influence of the nature of the metal ion on the rate of reduction of coordinated azomethine group


Medzhidov A. A. , Mamedova S. G. , Aydin A., Yalcin B. , Tascioglu S., Kaki E. H.

Russian Journal of General Chemistry, vol.77, no.10, pp.1761-1765, 2007 (Journal Indexed in SCI Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 77 Issue: 10
  • Publication Date: 2007
  • Doi Number: 10.1134/s1070363207100155
  • Title of Journal : Russian Journal of General Chemistry
  • Page Numbers: pp.1761-1765

Abstract

The kinetics of reduction of the azomethine bond in various Schiff bases and their transition metal complexes with sodium borohydride in dimethylformamide and ethanol solutions was studied. The reduction rate depends on both the structure of the starting Schiff bases and the nature of the metal ion. In transition metal N-phenylsalicylaldiminates, the rate of reduction of the azomethine group increases in the order Zn(II) < Ni(II) < Cu(II) < Co(II) < VO(II) < Mn(II). Similar trend is observed in other series of metal complexes with Schiff bases. The revealed trends are opposite to the Irving-Williams series of stability of complexes. This fact suggests that the major factor affecting the rate of reduction of the coordinated azomethine bond is the strength of its bonding with the metal ion. Depending on particular metal ion, the complexation can either decelerate or accelerate the reduction. © 2007 Pleiades Publishing, Ltd.