title: Heterometallic trinuclear {CoLn(III)} (Ln = Gd, Tb, Ho and Er) complexes in a bent geometry. Field-induced single-ion magnetic behavior of the Er(III) and Tb(III) analogues.
abstract: Through the use of a multi-site compartmental ligand, 2-methoxy-6-[{2-(2-hydroxyethylamino)ethylimino}methyl]phenol (LH3), the family of heterometallic, trinuclear complexes of the formula [CoLn(L)2(μ-O2CCH3)2(H2O)3]·NO3·xMeOH·yH2O has been expanded beyond Ln = Dy(III) to include Gd(III) (), Tb(III) (), Ho(III) () and Er(III) () for , and (x = 1; y = 1) and for (x = 0; y = 2). The metallic core of these complexes consists of a (Co(III)-Ln(III)-Co(III)) motif bridged in a bent geometry resulting in six-coordinated distorted Co(III) octahedra and nine-coordinated Ln(III) monocapped square-antiprisms. The magnetic characterization of these compounds reveals the erbium and terbium analogues to display a field induced single-ion magnetic behavior similar to the dysprosium analogue but at lower temperatures. The energy barrier for the reversal of the magnetization of the CoTb(III) analogue is Ueff ≥ 15.6(4) K, while for the CoEr(III) analogue Ueff ≥ 9.9(8) K. The magnetic properties are discussed in terms of distortions of the 4f electron cloud.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur-208016, India.
authors.forename: Joydeb
authors.initials: J
authors.lastname: Goura
authors.affiliation: Department of Physics, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK. p.goddard@warwick.ac.uk.
authors.forename: Jamie
authors.initials: J
authors.lastname: Brambleby
authors.affiliation: Department of Physics, Clarendon Laboratory, University of Oxford, Oxford, Parks Road, OX1 3PU, UK.
authors.forename: Craig V
authors.initials: CV
authors.lastname: Topping
authors.affiliation: Department of Physics, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK. p.goddard@warwick.ac.uk.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Goddard
authors.affiliation: National Institute of Science Education and Research Bhubaneswar, P.O. Jatni, Khurdha 752050, Odisha, India. vc@iitk.ac.in vc@niser.ac.in.
authors.forename: Ramakirushnan
authors.initials: R
authors.lastname: Suriya Narayanan
authors.affiliation: National Institute of Science Education and Research Bhubaneswar, P.O. Jatni, Khurdha 752050, Odisha, India. vc@iitk.ac.in vc@niser.ac.in.
authors.forename: Arun Kumar
authors.initials: AK
authors.lastname: Bar
authors.affiliation: Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur-208016, India and National Institute of Science Education and Research Bhubaneswar, P.O. Jatni, Khurdha 752050, Odisha, India. vc@iitk.ac.in vc@niser.ac.in.
authors.forename: Vadapalli
authors.initials: V
authors.lastname: Chandrasekhar