Three-dimensional metal piperazinyldiphosphonate phases with ellipsoidal cavities defined by 44-membered rings: Crystal structures of [M{O3PCH2NH(C2H4) 2NHCH2PO3}] · H2O, M = Mn and Co

Robert LaDuca, David Rose, Jeffrey R.D. DeBord, Robert C. Haushalter, Charles J. O'Connor, Jon Zubieta

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The hydrothermal reaction of a mixture of (Et4N)2MnCl4, N, N′-piperazinebis(methylenephosphonic acid), Et4NCl · H2O, and H2O in the mole ratio 1:1:5:300, adjusted to pH 5 with 40% aqueous (Bu4N)OH, at 160°C for 63 h yielded [Mn{O3PCH2NH(C2H4) 2NHCH2PO3}] · H2O (1) in 60% as offwhite platelets. The analogous reaction using (Et4N)2CoCl4 produced [Co{O3PCH2NH(C2H4) 2NHCH2PO3}] · H2O (2). The isomorphous materials 1 and 2 display three-dimensional network structures, based on binuclear units of corner-sharing metal and phosphorus tetrahedra, forming eight membered {-Co-O-P-O-}2 rings. The diphosphonate groups serve to tether the binuclear units into large ellipsoidal 44-membered rings. As the piperazinyl nitrogen atoms are protonated, the organic moiety of the disphosphonate group serves as both tether and charge compensating site. Compound 1 exhibits Curie-Weiss paramagnetism with weak antiferromagnetism between Mn centers. In contrast, the susceptibility of 2 exhibits a broad maximum at low temperatures consistent with short range antiferromagnetic coupling. Crystal data: 1, C6H16MnN2O7P2, triclinic P1, a = 8.393(2)Å, b = 9.043(2)Å, c = 9.125(2)Å, a = 62.88(3)°, β= 86.36(3)°, γ = 78.96(3)°, V = 604.8(3)Å3; R = 0.056 for 1663 reflections. 2, C6H16 CoN2O7P2, triclinic P1, a = 8.340(2)Å, b = 8.917(2)Å, c = 9.018(2)Å, α = 64.11(3)°, γ= 86.24(3)°, γ = 78.87(3)°, V = 591.9(2)Å3; R = 0.083 for 1917 reflections.

Original languageEnglish (US)
Pages (from-to)408-412
Number of pages5
JournalJournal of Solid State Chemistry
Issue number2
StatePublished - May 1996


ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Inorganic Chemistry
  • Materials Chemistry

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