Zwitterionic metal carboxylate complexes: In solid state

A flexible dicarboxylic acid having composition [(CH(o-C5H4N)(p-C6H4OCH2CO2H)2] derived from corresponding bis-phenol reacts with various metal(II) acetates such as manganese(II), cobalt(II) and nickel(II) acetate leads to zwtterionic complexes with compositions [CH(o-C5H4N)(p-C6H4OCH2CO2){p-C6H4OCH2CO2M(H2O)5}].6H2O (where M = Mn, Co, Ni). The complexes are characterised by X-ray crystallography. These complexes have chiral center due to unsymmetric structure conferred to the ligand through coordination at only one carboxylate group of the ligand. In solid state these complexes are racemic.

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► A new V-shaped prochiral dicarboxylic acid derived from bis-phenol is synthesized and characterized.
► The methine carbon of the ligand has a pyridine ring attached through the ortho carbon of the ring.
► Isostructural zwitterionic coordination complexes of this ligand with Mn, Co and Ni at +2 oxidation states are synthesised.
► Racemic mixtures of the zwitterionic complexes are obtained.