Synthesis, crystal structure, and spectroscopic characterization of two new binuclear complexes of manganese(II) and vanadium(V) with dipicolinate ligands containing 2-aminopyrimidinium as a counter cation

Abstract

Two new binuclear complexes, formulated as [(Hamp)[Mn(μ-dipic)Cl(H2O)2]]2 and [(Hamp)[V(μ-O)(O)(dipic)]·H2O]2 (dipicH2 = pyridine-2,6-dicarboxylic (dipicolinic) acid; amp = 2-aminopyrimidine), were synthesized by a hydrothermal process and characterized by elemental analysis, IR spectroscopy, thermal analysis, and X-ray single crystal diffraction. Both compounds contain two Hamp cations and a dinuclear manganese(II) or vanadium(V) anion complex. In addition, the vanadium complex contains two lattice water molecules. Two manganese(II) ions are bridged by pyridine-2,6-dicarboxylate ions in the manganese complex, and they are both coordinated by O,N,O of the tridentate dipicolinate ligand, one oxygen of another dipicolinate ligand, one chlorine, and two water molecules in a distorted pentagonal-bipyramidal geometry. Vanadium(V) ions are coordinated octahedrally by O,N,O of the tridentate dipicolinate ligand, one oxo ion, and two bridging μ-O ions in cis position in the vanadium complex. The crystal structures of both complexes are stabilized by a complex network of hydrogen bonds comprising water molecules, counter ion, and carboxyl groups of dipic2−.