Hydrothermal Syntheses and Crystal Structures of Two Oxovanadium - Organodiphosphonate Phases: [H2N(C2H4)2NH2][(VO)2(O3PCH2CH2CH2PO3H)2], a “Stair-Step” Structure Incorporating an Organic Cationic Template, and [(VO)(H2O){O3PCH2NH(C2H4)2NHCH2PO3}], a Layered Structure “Pillared” by a Piperazinium-Tethered Diphosphonate

Victoria Soghomonian, Jon Zubieta, Roberto Diaz, Robert C. Haushalter, J. Charles O'Connor

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Abstract

Two new members of the oxovanadium-organodiphosphonate system, V-O-R(PO3)24−, have been synthesized by hydrothermal methods and structurally characterized. The reaction of VCl4, propylenediphosphonic acid, piperazine, and H2O in the mole ratio 1:1.5:3:945 at 200 °C and 96 h yields [H2N(C2H4)2NH2][(VO)2(O3PCH2- CH2CH2PO3H)2] (1), as green rodlike crystals. The structure consists of ribbons of corner-sharing vanadium square pyramids and phosphorus tetrahedra interconnected by the diphosphonate organic backbone into a stair step structural motif. The reaction of VCl4, N, N'-piperazinebis(methylenephosphonic acid), and H2O in the mole ratio 1:0.8:570 at 125 °C for 134 h yields [(VO)(H2O){O3PCH2NH(C2H4)2NHCH2PO3}] (2), as light aqua green crystals of cubic habit. The structure of 2 consists of inorganic V/P/O layers linked through the organodiphosphonate backbone into an array of alternating inorganic and organic layers. In contrast to those in 1, the vanadium sites are six-coordinate and the V/P/O layer structure is a defected form of the V-P-O ribbon of 1 with alternate vanadium sites vacant. Compound 1 exhibits magnetic properties consistent with antiferromagnetic coupling of the V(IV) sites2 with J/k = −10.3 K as an estimate of the strength of the exchange. Crystal data: C10H26N2O14P4V2 (1), triclinic P1, a = 6.244(1) Å, b = 8.687(2) Å, c = 11.156(2) Å, a = 88.92(3)°, ß = 74.63(3)°, ? = 74.32(3)°, V = 560.8(3) Å3, Z = 1, Dcalc = 1.842 g cm−3, with structure solution and refinement based on 1663 reflections converging at R = 0.0662; C6H12N2O8P2V (2), monoclinic P21/c, a = 7.999(2) Å, b = 8.009(2) Å, c = 9.201(2) Å, ß= 100.24(3)°, V = 580.1(3) Å3, Z = 2, Dcalc = 2.021 g cm−3, 1453 reflections, R = 0.0593.

Original languageEnglish (US)
Pages (from-to)4460-4466
Number of pages7
JournalInorganic Chemistry
Volume34
Issue number17
DOIs
StatePublished - Aug 1 1995

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

Fingerprint Dive into the research topics of 'Hydrothermal Syntheses and Crystal Structures of Two Oxovanadium - Organodiphosphonate Phases: [H<sub>2</sub>N(C<sub>2</sub>H<sub>4</sub>)<sub>2</sub>NH<sub>2</sub>][(VO)<sub>2</sub>(O<sub>3</sub>PCH<sub>2</sub>CH<sub>2</sub>CH<sub>2</sub>PO<sub>3</sub>H)<sub>2</sub>], a “Stair-Step” Structure Incorporating an Organic Cationic Template, and [(VO)(H<sub>2</sub>O){O<sub>3</sub>PCH<sub>2</sub>NH(C<sub>2</sub>H<sub>4</sub>)<sub>2</sub>NHCH<sub>2</sub>PO<sub>3</sub>}], a Layered Structure “Pillared” by a Piperazinium-Tethered Diphosphonate'. Together they form a unique fingerprint.

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