Synthesis and structural characterization of Lindqvist type mixed-metal cluster anion [V2W4O19]4− in discrete and coordination polymer compounds

• Synthesis and characterization of Lindqvist type mixed-metal polyoxometalates.
• Compounds have been characterized by single crystal X-ray crystallography.
• Discrete cluster as well as coordination polymer containing compounds.
• In these crystal structures, supramolecular interactions are explored.
• Compounds are additionally characterized by 51V NMR spectroscopy and ICP analysis.

Two vanadium substituted Lindqvist type tungsten heteropolyanion containing compounds with molecular formulae [HMTAH]2[H2V2W4O19]·4H2O (1) and [Na2(H2O)4]n[H2V2W4O19]n·2nHMTA·2nH2O (2) have been synthesized, where HMTA is hexamethylenetetramine. Compound 1 is a discrete compound, whereas, compound 2 is a coordination polymer. Compounds 1–2 are characterized by routine elemental analyses, FT-IR spectroscopy, electronic absorption spectral analyses, thermogravimetric studies and single crystal X-ray crystallography. The presence of vanadium in the cluster anion is confirmed by 51V NMR spectroscopy, EDS and ICP analyses. The crystal structures of compounds 1 and 2 are refined in orthorhombic space group Immm and monoclinic space group C2/c respectively.

Compounds [HMTAH]2[H2V2W4O19]·4H2O (1) and [Na2(H2O)4]n[H2V2W4O19]n·2nHMTA·2nH2O (2) have been synthesized from an aqueous solution and characterized by routine analysis and single crystal X-ray crystallography. Compound 1 is a discrete cluster containing compound, whereas compound 2 is coordination polymer. Compounds 1 and 2 are additionally characterized by 51V NMR spectroscopy.Figure optionsDownload as PowerPoint slide