Synthesis and Structure of 12-Member Ring\nCrown-Shaped Oxovanadium Borophosphate\nPolyanions:  [H₃NC₂H₄NH₂C₂H₄NH₂C₂H₄NH₃]₄H[M(VO)₁₂{O₃POB(O)₂OPO₃}₆]·nH₂O (M = NH₄⁺, K⁺)

Abstract

Using multiethylenemultiamine to direct the crystallization of inorganic frameworks\nthrough multipoint hydrogen bonds, two new oxovanadium borophosphates, denoted VBP-J1 and VBP-J2, have been synthesized by hydrothermal methods as well as under reflux\nconditions. Powder X-ray diffraction patterns indicate that VBP-J1 and VBP-J2 are structural\nanalogues. Structure determinations show that both VBP-J1, [H₃NC₂H₄NH₂C₂H₄NH₂C₂H₄NH₃]₄H[NH₄(VO)₁₂{O₃POB(O)₂OPO₃}₆]·14H₂O and VBP-J2, [H₃NC₂H₄NH₂C₂H₄NH₂C₂H₄NH₃]₄H[K(VO)₁₂{O₃POB(O)₂OPO₃}₆]·16H₂O crystallize in the orthorhombic space group <i>Pbca</i>\nwith crystal data: <i>a</i> = 21.454(11) Å, <i>b</i> = 16.315(6) Å, <i>c</i> = 29.651(12) Å, α = β = γ = 90°, <i>V</i>\n= 10378(8) ų, <i>Z</i> = 4 for VBP-J1 and <i>a</i> = 21.537(2) Å, <i>b</i> = 16.2667(13) Å, <i>c</i> = 29.717(4) Å,\nα = β = γ = 90°, <i>V</i> = 10410.8(18) ų, <i>Z</i> = 4 for VBP-J2. VBP-J1 and VBP-J2 are constructed\nby edge-sharing {V₂O₁₀} binuclear unit and {BP₂O₁₀} trimer to form interesting 12-member\nring crown-shaped clusters with NH₄⁺ and K⁺ cations encapsulated in the clusters. The\nring diameters are 5.873 × 5.412 × 5.561 Å for VBP-J1 and 5.758 × 5.421 × 5.236 Å for\nVBP-J2. An extended network of multiple hydrogen bonds among anions, cations, and water\nmolecules links the structure in three dimensions.