X-ray structures, density functional theory study, DNA binding ability and micellization behaviour of decavanadates anions containing cationic organic moieties

Reported here synthesis, structure, DNA binding ability of three decavanadates complexes containing cationic organic moieties, 2-methylimidazolium (1), 4-dimethylaminopyridinium (2) and protonated 3-pyridiniumcarboxamide (3). Compounds are stable solids, characterized by elemental analyses, spectroscopic, single-crystal X-ray diffraction and theoretical studies. X-ray diffraction analysis indicates, the molecular structures of the compounds are composed of ion pairs formed by decavanadate ion [H2V10O28]4- and the corresponding cationic organic moieties. Complex 1 composed of decavanadate anion in combination with cationic 2-methylimidazolium and 2 contains decavanadate moiety with counter cation protonated 4-dimethylaminopyridine, two DMSO molecules. The structure of 3 consists of [H2V10O28]4-, protonated 3-pyridinecarboxamide, two cocrystallized neutral organic moieties with two molecules of water. The effective interaction of the ion-pair and hydrogen bonding interaction resulted in the cohesion, stabilization of solid state structure of the complexes. In solid state, compounds present interesting assemblies through the formation of H-bonds analyzed using DFT calculations and quantum theory of atoms in molecules (QTAIM). Interaction of the compounds with CTDNA studied by absorption and fluorescence spectroscopy, show moderately strong intercalative mode of binding. Additionally micellization behaviour of the complexes using surfactant CTAB was studied by conductance measurements and absorption spectroscopy. The complexes show an increased solubility on addition of the surfactant.

Automated summary

The synthesis, structure, and DNA binding ability of three decavanadate complexes containing cationic organic moieties were reported. The complexes were characterized by various techniques and their solid-state structures were analyzed. The complexes showed interesting assembly patterns and exhibited moderately strong intercalative binding with CTDNA. Additionally, their micellization behavior in the presence of the surfactant CTAB was studied.