Syntheses, Characterization, and Structures of Polynuclear Tartrato and Malato Complexes of Bivalent Manganese

Abstract

Polymeric [Mn2(C4H4O6)2(H2O)].nH2O(n=2.71), [Mn(C4H4 O5)(H2O)2].H2O have been synthesized by reacting freshly prepared MnO(OH), 40%HF and corresponding α-hydroxycarboxylic acid from aqueous medium. Compounds were characterized on the basis of elemental analyses, spectroscopic, and X-ray diffraction studies. [Mn2(C4H4O6)2(H2O)].nH2O(n=2.71) crystallizes in space group P21 and three-dimensional structure consist of corrugated sheets of [Mn2{(R,R)-C4H4O6}2(H2O)] and water molecules. [Mn(C4H4O5)(H2O)2]. H2O crystallizes in space group Pbca and polymeric structure is formed of infinite number of dimeric units of Mn2[(C4H4O5)(H2O)2]2.2H2O. Hydrogen bonding interaction is operative in the crystal lattice of the compounds. Room temperature magnetic moments for tartrato and malato complexes are 5.12 and 5.47 BM respectively. Complexes exhibit fluorescence emission in solid state.