title: First coordination compounds based on a bis(imino nitroxide) biradical and 4f metal ions: synthesis, crystal structures and magnetic properties.
abstract: The synthesis, crystal structures and magnetic properties of two families of heterospin complexes containing lanthanide ions and a bis(imino nitroxide) biradical (IPhIN = 1-iodo-3,5-bis(4',4',5',5'-tetramethyl-4',5'-dihydro-1H-imidazole-1'-oxyl)benzene) are reported: in [Ln2(hfac)6(IPhIN)(H2O)2] compounds, two lanthanide ions [Ln = Gd(III) (1) and Dy(III) (2)] are coordinated to the biradical, and in [Ln(hfac)3(IPhIN)(H2O)] compounds, one lanthanide ion (Ln = Tb(III) (3), Gd(III) (4) or Dy(III) (5)) is coordinated to the biradical. Ferromagnetic intramolecular magnetic interactions between Gd(III) and the biradical were found for 1 and 4, while intramolecular magnetic interactions between the radicals were ferro- and antiferromagnetic, respectively. Compound 2 shows a field induced slow relaxation of magnetization, which (under an external applied field of 2 kOe) exhibits an activation energy barrier of ΔE/kB = 27 K and a pre-exponential factor of 1.4 × 10(-8) s. To support the magnetic characterization of compound 3ab initio calculations were also performed.
authors.affiliation: Instituto de Química, Universidade Federal Fluminense, Niterói 24020-150, RJ, Brazil. mariavaz@vm.uff.br.
authors.forename: Samira G
authors.initials: SG
authors.lastname: Reis
authors.forename: Matteo
authors.initials: M
authors.lastname: Briganti
authors.forename: Daniel O T A
authors.initials: DO
authors.lastname: Martins
authors.forename: Handan
authors.initials: H
authors.lastname: Akpinar
authors.forename: Sergiu
authors.initials: S
authors.lastname: Calancea
authors.forename: Guilherme P
authors.initials: GP
authors.lastname: Guedes
authors.forename: Stéphane
authors.initials: S
authors.lastname: Soriano
authors.forename: Marius
authors.initials: M
authors.lastname: Andruh
authors.forename: Rafael A A
authors.initials: RA
authors.lastname: Cassaro
authors.forename: Paul M
authors.initials: PM
authors.lastname: Lahti
authors.forename: Federico
authors.initials: F
authors.lastname: Totti
authors.forename: Maria G F
authors.initials: MG
authors.lastname: Vaz