title: Studies of a linear single-molecule magnet.
abstract: Reaction of the dinuclear complex [Mn2O2(bpy)4](ClO4)3 with H3cht (cis,cis-l,3,5-cyclohexanetriol) in MeCN produces the complex [Mn3(Hcht)2(bpy)4](ClO4)3.Et2O.2MeCN (1.Et2O.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 (94 GHz) 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 B4(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 approximately 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.
authors.affiliation: School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh, UK.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Prescimone
authors.forename: Joanna
authors.initials: J
authors.lastname: Wolowska
authors.forename: Gopalan
authors.initials: G
authors.lastname: Rajaraman
authors.forename: Simon
authors.initials: S
authors.lastname: Parsons
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wernsdorfer
authors.forename: Murlaee
authors.initials: M
authors.lastname: Murugesu
authors.forename: George
authors.initials: G
authors.lastname: Christou
authors.forename: Stergios
authors.initials: S
authors.lastname: Piligkos
authors.forename: Eric J L
authors.initials: EJ
authors.lastname: McInnes
authors.forename: Euan K
authors.initials: EK
authors.lastname: Brechin