Modular [(Fe8M6II)-M-III](&ITn&IT+)(M-II = Pd, Co, Ni, Cu) Coordination Cages

Research output: Contribution to journalArticle

  • External authors:
  • Sergio Sanz
  • Helen M. O'Connor
  • Priyanka Comar
  • Amgalanbaatar Baldansuren
  • Mateusz B. Pitak
  • Simon J. Coles
  • Hogni Weihe
  • Paul J. Lusby
  • Stergios Piligkos
  • Euan K. Brechin

Abstract

The reaction of the simple metalloligand [FeIIIL3] [HL = 1-(4-pyridyl)butane-1,3-dione] with a variety of different MII salts results in the formation of a family of heterometallic cages of formulae [FeIII8PdII6L24]Cl12 (1), [FeIII8CuII6L24(H2O)4Br4]Br8 (2), [FeIII8CuII6L24(H2O)10](NO3)12 (3), [FeIII8NiII6L24(SCN)11Cl] (4), and [FeIII8CoII6L24(SCN)10(H2O)2]Cl2 (5). The metallic skeleton of each cage describes a cube in which the FeIII ions occupy the eight vertices and the MII ions lie at the center of the six faces. Direct-current magnetic susceptibility and magnetization measurements on 3–5 reveal the presence of weak antiferromagnetic exchange between the metal ions in all three cases. Computational techniques known in theoretical nuclear physics as statistical spectroscopy, which exploit the moments of the Hamiltonian to calculate relevant thermodynamic properties, determine JFe–Cu = 0.10 cm–1 for 3 and JFe–Ni = 0.025 cm–1 for 4. Q-band electron paramagnetic resonance spectra of 1 reveal a significantly wider spectral width in comparison to [FeL3], indicating that the magnitude of the FeIII zero-field splitting is larger in the heterometallic cage than in the monomer.

Bibliographical metadata

Original languageEnglish
Pages (from-to)3500-3506
JournalInorganic Chemistry
Volume57
Issue number7
Early online date11 Jan 2018
DOIs
Publication statusPublished - 2 Apr 2018