title: Tuning of inter- versus intrachain magnetic interactions in cyano-bridged Ni(II)/M(III) (M = Cr, Fe, Co) chain complexes.
abstract: The reaction of [M(CN)6]3- (M = Cr3+, Fe3+, Co3+) with the nickel(II) complex of 2,4-diamino-1,3,5-triazin-6-yl-{3-(1,3,5,8,12-pentaazacyclotetradecane)} ([NiL]2+) in excess of ANO3 or ACl (A = Li+, Na+, K+, Rb+, Cs+, NH4+) leads to the cyano-bridged dinuclear assemblies A{[NiL][M(CN)6]}.xH2O (x = 2-5). X-ray structures of Li{[NiL][Cr(CN)6]}.5H2O, NH4{[NiL][Cr(CN)6]}.3.5H2O, K{[NiL][Cr(CN)6]}.4H2O, K{[NiL][Fe(CN)6]}.4H2O, Rb{[NiL][Fe(CN)6]}.3.5H2O, and Cs{[NiL][Fe(CN)6]}.3.5H2O, as well as the powder diffractometry of the entire Fe(III) series, are reported. The magnetic properties of the assemblies are dependent on the monocation A and discussed in detail. New efficient pathways for ferromagnetic exchange between Ni(II) and Fe(III) or Cr(III) are demonstrated. Field dependencies of the magnetization for the Fe(III) samples at low temperature and low magnetic field indicate a weak interchain antiferromagnetic coupling, which is switched to ferromagnetic coupling at increasing magnetic field (metamagnetic behavior). The interchain magnetic coupling can be tuned by the size of the A cations.
authors.affiliation: Universität Heidelberg, Anorganisch-Chemisches Institut, Im Neuenheimer Feld 270, D-69120 Heidelberg, Germany.
authors.forename: Mihail
authors.initials: M
authors.lastname: Atanasov
authors.forename: Peter
authors.initials: P
authors.lastname: Comba
authors.forename: Sebastian
authors.initials: S
authors.lastname: Förster
authors.forename: Gerald
authors.initials: G
authors.lastname: Linti
authors.forename: Thomas
authors.initials: T
authors.lastname: Malcherek
authors.forename: Ronald
authors.initials: R
authors.lastname: Miletich
authors.forename: Alexander I
authors.initials: AI
authors.lastname: Prikhod'ko
authors.forename: Hubert
authors.initials: H
authors.lastname: Wadepohl