Synthesis, spectroscopic characterization, thermal analysis and electrical conductivity studies of Mg(II), Ca(II), Sr(II) and Ba(II) vitamin B2 complexes

Riboflavin (RF) complexes of Mg(II), Ca(II), Sr(II) and Ba(II) were successfully synthesized. Structures of metal complexes obtained were confirmed and characterized by elemental analysis, molar conductance, and infrared spectra. DC electrical conductivity measurements indicated that the alkaline earth metal (II) complexes of RF ligand are non-electrolytes. Elemental analysis of chelates suggest that the metal(II) ligand ratio is 1:2 with structure formula as [M(RF)(2)(X)(2)]center dot nH(2)O. Infrared assignments clearly show that RF ligand coordinated as a bidentate feature through azomethine nitrogen of pyrazine ring and C=O of pyrimidine-2,4-dione. Thermal analyses of Mg(II), Ca(II). Sr(II) and Ba(II) complexes were investigated using (TG/DSC) under atmospheric nitrogen between 30 and 800 degrees C. The surface morphology of the complexes was studied by SEM. The electrical conductivities of RF and its metal complexes were also measured with DC electrical conductivity in the temperature range from room to 483 K. (c) 2011 Elsevier B.V. All rights reserved.