Coordination Compounds of Schiff Base Containing Urea Moiety

Characterization and Geometrical Assignment of Coordination Compounds

Abstract

A MeOH solution of salicylaldehyde and o–hydroxyphenylurea in 11 molar ratio reacts and forms the Schiff base, LH3 (1). A MeOH solution of the latter reacts with Zn(II), Co(II), Ni(II), Fe(III) and Zr(OH)2(IV) ions in 11 molar ratio and forms the corresponding coordination compounds, [Zn(LH)(MeOH)] (2), [M(LH)(MeOH)2]2 (3, M = Co, Ni), [FeCl(LH)(MeOH)]2 (4) and [Zr(OH)2(LH)(MeOH)2] (5). The coordination compounds have been characterized on the basis of elemental analyses, molecular weight, molar conductance, spectral (IR, reflectance, NMR) studies, thermo-gravimetric analyses and magnetic susceptibility measurements. 1 acts as a dibasic tridentate ONO donor ligand in 2-5. The coordination compounds, 3 and 4 are paramagnetic, while 2 and 5 are diamagnetic. A tetrahedral geometry to 2, an octahedral geometry to 3 and 4 and a pentagonal-bipyramidal geometry to 5 are assigned. The energy optimized structures, 6 and 7 for 1 and 2 respectively are proposed using the semiempirical ZINDO1 quantum mechanical calculations.