| Abstract
| - The hydrothermal chemistry of theCsVO3/methylenediphosphonate system was investigated.Variations in reactiontemperatures, heating times, and stoichiometries of reactants resultedin the isolation of mononuclear, one-, two-,and three-dimensional species: Cs[VO(HO3PCH2PO3H)2(H2O)](1),Cs[VO(HO3PCH2PO3)](2), Cs[(VO)2V(O3PCH2PO3)2(H2O)2](3), and[V(HO3PCH2PO3)(H2O)](4), respectively. The structure of the anion of1 consistsof isolated V(IV) octahedra. Phase 2 adopts a chainstructure constructed from corner-sharing V(IV) octahedra,forming infinite {−VOVO−} linkages. The layerstructure of 3 contains trinuclear units ofcorner-sharing{VO6} octahedra with the central V site in the IIIoxidation state and V(IV) centers at the extremities ofthecluster. The diphosphonate ligands serve to link neighboringtrinuclear motifs into a layer structure three octahedrain depth. The Cs+ cations occupy cavitieswithin the layers, rather than the more common interlamellarpositions.The structure of 4 consists of isolated{V(III)O6} octahedra linked by diphosphonategroups into a three-dimensionalframework. Crystal data: for 1,CH6O7P2V0.5Cs,monoclinic C2, a = 10.991(2) Å,b = 10.161(2) Å, c =7.445(1) Å, β = 92.97(3)°, Z = 4; for2, CH3O7P2VCs,monoclinic C2, a = 10.212(2) Å,b = 10.556(2) Å, c =14.699(3) Å, β = 94.57(2)°, Z = 8; for3,C2H8O16P4V3Cs,monoclinic C2/m, a = 9.724(2) Å,b = 8.136(2) Å,c = 10.268(2) Å, β = 103.75(3)°,Z = 2; for 4,CH5O7P2V, monoclinicP21/n, a =5.341(1) Å, b = 11.516(2)Å, c = 10.558(2) Å, β = 99.89(1)°,Z = 4.
- Hydrothermal reactions ofCsVO3 with methylenediphosphonate yield one-, two-, andthree-dimensional solid phases,Cs[VO(HO3PCH2PO3)],Cs[(VO)2V(O3PCH2PO3)2(H2O)2],and[V(HO3PCH2PO3)(H2O)],respectively, depending on reaction conditions. A view of thestructure of the anionic oxovanadium phosphonate chains ofCs[VO(HO3PCH2PO3)]is shown in the accompanyinggraphic.
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