Supramolecular structures of mononuclear and dinuclear dioxomolybdenum(VI) complexes via hydrogen bonds and π–π stacking, thermal studies and electrochemical measurements

Two dioxomolybdenum(VI) complexes, [Mo2O4(HBAP)2L] (1) and [MoO2(HMBI)] (2) (HBAP = ((E)-2-(2-hydroxybenzylidene)amino)phenol, HMBI = ((E)-N′-(2-hydroxy-3-ethoxybenzylidene)isonicotinohydrazide) and L = (4,4′-dipyridyl)), have been synthesized and structurally characterized by elemental analysis, 1H NMR spectroscopy and X-ray single crystal diffraction analysis. In complex (1), a 1D-chain is formed through C⋯H⋯O hydrogen-bonding interactions. In complex (2), a dimer is formed through O⋯H⋯N hydrogen-bonding interactions. This dimer is extended into a 1D chain through secondary C⋯H⋯O hydrogen-bonding interactions, in addition to π–π stacking interactions. Electrochemical measurements showed that both complexes undergo an irreversible reduction in DMF solution. The thermogravimetric analyses clearly indicate that the complexes have high thermal stability.

Graphical abstractPacking diagram of complex (1) around b axis. Hydrogen atoms are omitted for clarity.Figure optionsDownload full-size imageDownload as PowerPoint slide