Synthesis and Characterization of Template Cr(III),Fe(III), Mn(II), Cd(II) and V(IV), Complexes Derived from 2,6- Diaminopyridine and 1,4-Dihydro-Quinoxalin-2,3-dione.

Abstract

A new series of tetradentate N2O2 acyclic complexes of type (M(L)X2)Xn where M = Mn(II), Cd, Cr(III) and Fe(III); L is tetradentate acyclic Schiff base formed via condensation reaction, and X = Cl-, n=1 for M(III), have been prepared on the basis of condensation of 2,6-diaminopyridine and 1,4-dihydro-quinoxalin-2, 3-dione by template method. The complexes are formulated as: (M(L)Cl)Cl where M=Cr, Fe(III),(MLCl2),MII=Mn, Cd(II) and (VOL)SO4 on the basis of elemental analyses,molar conductance and other spectral data. The organic moiety formed up on template condensation behaves as tetradentate N2O2 system through the two azomethine nitrogen atoms of -C=N- and the participation of O atoms of -C=O in 2- position of pyrazine ring. However, the pyridine nitrogen atom does not take part in coordination as confirmed by FTIR,UV-Visible and H NMR spectroscopy data. The newly template metal complexes have characterized with the help of various spectral techniques H NMR,13C NMR, F.T.I.R, elemental analyses, electronic spectra, molar conductivity measurements and magnetic susceptibilities. The octahedral geometry has been proposed for Cr(III),Fe(III), Mn (II) and Cd(II) while vanadyl complex was square pyramid configuration respectively. Keywords: Template complex, Quinoxaline-3, 2-dione, Schiff bases.