Dimensional Open Framework Structures From Inorganic Building Blocks To Build A Tunnel Or Spiral Chain Compounds Synthesis And Characterization

In this paper, four novel 3-D open framework compound with tunnels or helical chains: [C2N2H10]{(VO)(VO2)[V(OH2)](PO3.5)4}·H2O (1) (C3N2H12)4{CdMo12O24(HPO4)4(PO4)4(OH)6[Cd(H2O)]2}·4H2O (2) [La(pydc)2(H2O)][La(pydc)(H2O)2]·H2O (3) [Sm(pydc)2(H2O)][Sm(pydc) (H2O)2]·H2O (4) have been hydrothermally synthesized through modifying synthetic conditions, starting materials and PH value. Structures of the six complexes have been determined by X-ray single crystal diffraction, and the influencing factors on structures have been discussed. The basic structural unit of compound (1) is {V3P4O18} building block, which is made up of tri-polymeric {V3O16} by edge-sharing fixed by four {PO4} tetrahedra. {V3P4O18} building blocks form novel 3-D open framework by corner-sharing, inorganic framework shows interesting 10-member rings network and forms novel 1-D tunnels along a axis. There are strong hydrogen bonding interactions between inorganic and guest molecules. Compound (2) represent a kind of novel molybdenum phosphate, {Mo6P4} units are linked by six-coordinated Cd(1) forming polymer[Cd{Mo6P4}2], which are connected by Cd(2) forming novel 3-D open framework with intersecting tunnels. Furthermore, bulk-modified carbon paste electrode is first used to study the electrochemical properties of hydrothermally synthesized compound. Compound (3) and (4) are isostructural compounds containing lanthanide binuclear dimer and 1-D lanthanide helical chain. La(2) and La(2A) are connected by two μ3-O of different pydc to form a central symmetrical dimer. La(1) were connected by the different oxygen atom of carboxyl and form a helical-shaped (O-La-O)n chain along 21 helical axes. The pydc ligands chelate coordinated to La(1) distributes around 21 helical axes. The adjacent La(1) on the chain connect lanthanide binuclear polymer with opposite direction. Z-shaped layer are connected by carboxyl of pydc to form a 3-D framework. Other characterizations for these six complexes by elemental analysis, IR, ESR, XPS, and thermal analysis have also been described.