title: Studies of a nickel-based single-molecule magnet.
abstract: A cyclic complex [Ni(12)(chp)(12)(O(2)CMe)(12)(thf)(6)(H(2)O)(6)] (1) has been synthesised and studied (chp=6-chloro-2-pyridonate). Complex 1 exhibits ferromagnetic exchange between the S=1 centres, giving an S=12 spin ground state. Detailed studies demonstrate that it is a single-molecule magnet with an energy barrier of approximately 10 K for reorientation of magnetisation. Resonant quantum tunnelling is also observed. The field between resonances allows accurate measurement of D, which is 0.067 K. Inelastic neutron scattering studies have allowed exchange parameters to be derived accurately, which was impossible from susceptibility data alone. Three exchange interactions are required: two ferromagnetic nearest neighbour interactions of approximately 11 and 2 cm(-1) and an anti-ferromagnetic next nearest neighbour interaction of -0.9 cm(-1).
authors.affiliation: Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Switzerland.
authors.forename: Hanspeter
authors.initials: H
authors.lastname: Andres
authors.forename: Reto
authors.initials: R
authors.lastname: Basler
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Blake
authors.forename: Cyril
authors.initials: C
authors.lastname: Cadiou
authors.forename: Gregory
authors.initials: G
authors.lastname: Chaboussant
authors.forename: Craig M
authors.initials: CM
authors.lastname: Grant
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Güdel
authors.forename: Mark
authors.initials: M
authors.lastname: Murrie
authors.forename: Simon
authors.initials: S
authors.lastname: Parsons
authors.forename: Carley
authors.initials: C
authors.lastname: Paulsen
authors.forename: Fabrizzio
authors.initials: F
authors.lastname: Semadini
authors.forename: Vincent
authors.initials: V
authors.lastname: Villar
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wernsdorfer
authors.forename: Richard E P
authors.initials: RE
authors.lastname: Winpenny