Crystal structure, vibrational spectra and thermal analysis of a new centrosymmetric transition metal phosphate compound, Mn(H2PO4)2•4H2O

The crystal of Manganese(II) bis(aqua) bis(dihydrogen phosphate) dihydrate, Mn(H2O)(2)(H2PO4)(2)center dot 2H(2)O (Mn(H2PO4)(2)center dot 4H(2)O), was obtained for the first time. Its structure was solved by the X-ray method at room temperature. The crystal belong to the P (1) over bar space group of the triclinic system (a = 7.788(3) angstrom, b = 7.881(3) angstrom, c = 9.322(4) angstrom, alpha = 66.90(4), beta = 84.75(2)degrees, gamma = 72.71(3)degrees, V = 502.3(3) angstrom(3) and Z = 2). The structure is composed of Mn(O)(4)(Ow)(2) octahedra and H2PO42- tetrahedra, located at C-1 sites and forming octahedral-tetrahedral infinite chains which are linked by the oxygen atoms to layers and further to a three-dimensional framework. The proposed hydrogen-bonding scheme provides further linkage within the chains. IR, Raman, TGA and DSC results were interpreted on the basis of the formula of the title compound and its crystal structure. (C) 2012 Elsevier B.V. All rights reserved.