Synthesis and Characterisation of a Novel 2,3-O-di Acetyl- 5,6-O-Benzylidene - L -Ascorbic Acid and its Complexes of Cr(III), Co(II), Ni(II),Cu(II) and Zn(II)

new ligand type (O2) [2,3-O-diacety l-5,6-O-benzy lidene L- ascorbic acid] [L] and its complexes of general formula [M(L)2(X)(Y)]Cln (where: M=Cr^III ,X=Y=H2O, n=3; Co^II, X = Y = 0, n= 2; Ni^II and Cu^II, X = Cl, Y = H2O, n= 1; Zn^II, X = Y = H2O,n = 2) are reported. The ligand was prepared in two steps; first step involved the sy nthesis of [5,6-O-benzylidene-L-ascorbic acid] (A). In second step derivative-A was then reacted with acety l chloride and anhydrous pyridine as a base to give the titled ligand. Metal complexes of the ligand with Cr^III,Co^II,Ni^II,Cu^II and Zn^II were sy nthesised by direct reaction of the corresp onding metal chloride with the ligand[L] in a 2L:1M mole ratio. The ligand and its complexes were characterised by sp ectroscopic methods 1H NM R, FTIR, (UV-Vis), atomic absorption, microanalyses, chloride content, melting point and conductance measurements . These studies revealed that the geometry about Cr^III, Ni^II,Cu^II and Zn6II is octahedral while the complex of Co ^II adopts a tetrahedral geometry .