title: Rationalisation of weak ferromagnetism in manganese(III) chains: the relation between structure and ordering phenomena.
abstract: The synthesis, structure and magnetic properties of the one-dimensional chain compounds [Mn(cyclam)(SO4)]ClO4.H2O (1) and [Mn(cyclam)(HCOO)](CF3SO3)(ClO4) (2) are reported. Cyclam is the cyclic tetradentate ligand 1,4,7,11-tetraazacyclotetradecane. Both chain compounds exhibit antiferromagnetic interactions within the chains. A magnetic ordering phase transition at 5.5 K in (1) is investigated by magnetisation measurements along the three principal crystallographic axes of a single crystal and the results show unambiguously that the ferromagnetic ordering is only taking place along one crystallographic axis. The spin structure of the magnetic ordered phase and the magnitude of the ferromagnetic moment are correlated with the crystal structure and symmetry of the compound.
authors.affiliation: Department of Chemistry, University of Copenhagen, Denmark.
authors.forename: Susanne
authors.initials: S
authors.lastname: Mossin
authors.forename: Høgni
authors.initials: H
authors.lastname: Weihe
authors.forename: Henning Osholm
authors.initials: HO
authors.lastname: Sørensen
authors.forename: Nicola
authors.initials: N
authors.lastname: Lima
authors.forename: Roberta
authors.initials: R
authors.lastname: Sessoli
mesh_terms: D018360:Crystallography, X-Ray; D006571:Heterocyclic Compounds / Q000737:chemistry; D008280:Magnetics; D017895:Manganese Compounds / Q000737:chemistry*; D008958:Models, Molecular; D013696:Temperature
chemical_list: D006571:Heterocyclic Compounds; D017895:Manganese Compounds