High-spin Ni3Fe2(CN)6 and Cu 3Cr2(CN)6 clusters based on a trigonal bipyramidal geometry

Bart M. Bartlett*, T. David Harris, Marty W. DeGroot, Jeffrey R. Long

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

20 Scopus citations


The synthesis and characterization of two new cyanobridged cluster compounds, [Tp2(cyclen)3NiII3Fe III2(CN)6](BF4)4 (1) and [(Me3tacn)5CuII3Cr III2(CN)6](ClO4)6 (2), are reported. The structure of each cluster is based upon a trigonal bipyramidal geometry, and ferromagnetic coupling between constituent metal ions is shown to give rise to S = 4 and S = 9/2 ground states, respectively. A room-temperature assembly reaction generates a purple form of compound 2, wherein two cyanide stretching frequencies in the infrared spectrum (vCN = 2094, 2156 cm-1) indicate partial isomerism of the cyanide bridging ligands. The X-ray crystal structure confirms this isomerism via examination of the C and N thermal parameters. At -40 °C, a metastable green form of the com-pound is instead isolated, for which a single cyanide stretch at vCN = 2156 cm_1 is consistent with an unisomerized cluster. The temperature-dependence of the magnetization under varying applied field reveals significant axial anisotropy in compound 1, with a significant axial zero-field splitting while compound 2 shows no zero-field splitting in either isolated form. In line with the observed anisotropy, AC magnetic susceptibility measurements performed on compound 1 reveal a frequency-dependent out-of-phase signal suggestive of single-molecule magnet behavior.

Original languageEnglish (US)
Pages (from-to)2380-2385
Number of pages6
JournalZeitschrift fur Anorganische und Allgemeine Chemie
Issue number13-14
StatePublished - Nov 5 2007


  • Cluster compounds
  • Cyanides
  • Magnetic properties
  • Single-molecule magnets
  • Trigonal bipyramid

ASJC Scopus subject areas

  • Inorganic Chemistry

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