Cation-anion interactions and polar structures in the solid state

Michael R. Marvel, Julien Lesage, Jaewook Baek, P. Shiv Halasyamani, Charlotte L. Stern, Kenneth R. Poeppelmeier

Research output: Contribution to journalArticle

145 Citations (Scopus)

Abstract

Complicated structures where oxygen and fluorine are found together in one framework, where deviations from Pauling's second crystal rule (PSCR) are expected, often result in structures with important physical properties. The [NbOF5]2- anion and therefore all the individual Nb-O and Nb-F bonds are ordered in noncentrosymmetric KNaNbOF5 and centrosymmetric CsNaNbOF5. The Na/K- and Na/Cs-O/F interactions in these phases, in particular the expected deviations from PSCR and the bond valence model, reveal the essential role of the small potassium cations in the acentric packing of the [NbOF5]2- anion. KNaNbOF 5 crystallizes in the orthorhombic and polar space group Pna2 1 (No. 33) with lattice constants a = 11.8653(11) Å, b = 5.8826(6) Å, c = 8.1258(8) Å, and Z = 4, while CsNaNbOF5 crystallizes in the orthorhombic space group Pbcn (No. 60) with lattice constants a = 8.3155(7), b = 13.3176(11), c = 11.1314-(9), and Z = 8.

Original languageEnglish
Pages (from-to)13963-13969
Number of pages7
JournalJournal of the American Chemical Society
Volume129
Issue number45
DOIs
Publication statusPublished - Nov 14 2007

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ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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