Studies of a linear single-molecule magnet

Alessandro Prescimone, Joanna Wolowska, Gopalan Rajaraman, Simon Parsons, Wolfgang Wernsdorfer, Murlaee Murugesu, George Christou, Stergios Piligkos, Eric J. L. McInnes, Euan K. Brechin

Research output: Contribution to journalArticlepeer-review

Abstract

Reaction of the dinuclear complex [Mn2O2(bpy)(4)](ClO4)(3) with H(3)cht (cis, cis- 1,3,5-cyclohexanetriol) in MeCN produces the complex [Mn-3(Hcht)(2)(bpy)(4)](ClO4)(3)center dot Et2O center dot 2MeCN (1 center dot Et2O center dot 2MeCN). Dc magnetic susceptibility measurements reveal the existence of weak ferromagnetic exchange between the three Mn ions, leading to a spin ground state of S = 7, with D= -0.23 cm(-1). W-Band (94GHz) EPR measurements on restrained powdered crystalline samples confirm the S = 7 ground state and determine the ground state zero-field splitting (ZFS) parameters of D = -0.14 cm(-1) and B-4(0)= + 1.5 x 10(-5) cm(-1). The apparent 4th order behaviour is due to a breakdown of the strong exchange limit approximation (J approximate to d, the single-ion ZFS). Single crystal dc relaxation decay and hysteresis loop measurements reveal the molecule to have an appreciable energy barrier to magnetization relaxation, displaying low temperature sweep rate and temperature-dependent hysteresis loops. Density functional studies confirm the ferromagnetic exchange coupling between the Mn ions.

Original languageEnglish
Pages (from-to)5282-5289
Number of pages8
JournalDalton Transactions
Issue number45
DOIs
Publication statusPublished - 2007

Keywords

  • HIGH-SPIN MOLECULES
  • NEUTRON-SCATTERING SPECTRA
  • GAUSSIAN-BASIS SETS
  • ENERGY-LEVELS
  • ATOMS LI
  • MAGNETIZATION
  • CLUSTERS
  • EXCHANGE
  • ANISOTROPY
  • COMPLEXES

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