Influence of Zero-Field Splitting and State Mixing on Ferromagnetic Exchange in the Integrated-Stack Charge-Transfer Salt [Cp*2Fe]+[Co(HMPA-B)]-

David M. Eichhorn, Joshua Telser*, Charlotte L. Stern, Brian M. Hoffman

*Corresponding author for this work

Research output: Contribution to journalArticle

8 Scopus citations

Abstract

We have prepared and studied the charge-transfer salts [Cp*2M]+[Co(HMPA-B)]- (M = Fe (1), Co (3), Cp* = pentamethylcyclopentadienyl, HMPA-B = bis(2-hydroxy-2-methylpropanamido)benzene). X-ray crystallographic analysis (orthorhombic Pmmn, a = 10.780(2) Å, b= 16.211(4) Å, c = 9.350(1) Å, V = 1634(1) Å3, R = 0.034, Rw = 0.038) shows 1 to form integrated stacks where the S=½ [Cp*2Fe]+ cation alternates with the planar [Co(HMPA-B)]- anion. Susceptibility measurements on 3, which contains the diamagnetic [Cp*2Co]+ cation, show that the Co111 of the anion exhibits a zero-field-split (D = 45 cm−1) S = 1 electronic configuration. The situation in the two-spin crystal, 1, is the inverse of that seen in the bulk ferromagnet [Cp*2Mn]+[TCNQ]-, where the cation has S = 1 and the anion has S = ½, but susceptibility measurements show that 1 does not order magnetically. Analysis of the interplay between exchange and a zero-field splitting (ZFS) on the anion indicates that 1 displays a substantial ferromagnetic coupling between cation and anion (J ≈ −7 cm−1 where H= JS1·S2). However, this exchange is manifest as an increase in the apparent g-values of the cation that arises from quantum-mechanical state mixing in the presence of the large ZFS.

Original languageEnglish (US)
Pages (from-to)3533-3537
Number of pages5
JournalInorganic chemistry
Volume33
Issue number16
DOIs
StatePublished - Aug 1 1994

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

Fingerprint Dive into the research topics of 'Influence of Zero-Field Splitting and State Mixing on Ferromagnetic Exchange in the Integrated-Stack Charge-Transfer Salt [Cp*<sub>2</sub>Fe]<sup>+</sup>[Co(HMPA-B)]<sup>-</sup>'. Together they form a unique fingerprint.

  • Cite this