title: Bulk weak ferromagnet in ferrimagnetic chains of organic-inorganic hybrid materials based on BDH-TTP and paramagnetic thiocyanato complex anions: (BDH-TTP)[M(isoq)(2)(NCS)(4)], M = Cr(III), Fe(III).
abstract: The preparation, X-ray crystal structures, and magnetic properties of two new isostructural charge transfer salts, (BDH-TTP)M(isoq)(2)(NCS)(4) (M = Cr(III) (1), Fe(III) (2), BDH-TTP = 2,5-bis(1,3-dithiolan-2-ylidene)-1,3,4,6-tetrathiapentalene, isoq = isoquinoline), are reported. Crystal data for 1: monoclinic, space group C2/c (#15), a = 16.1363(9) A, b = 19.0874(12) A, c = 12.5075(6) A, beta = 95.70(4) degrees, V = 3833.2(4) A(3), Z = 4, R = 0.0516 for 2844 reflections with I > 2 sigma(I); for 2: monoclinic, C2/c (#15), a = 16.1938(8) A, b = 19.1117(11) A, c = 12.5100(10) A, beta = 94.265(3) degrees, V = 3861.0(4) A(3), Z = 4, R = 0.0479 for 2969 reflections with I > 2 sigma(I). The crystal structure consists of zigzag mixed organic and inorganic layers, and each layer is formed by mixed columns of BDH-TTP radical cations and paramagnetic metal complex anions. Short intermolecular atomic contacts between donor and anion are observed within the column in the c-direction. The two compounds have weak room-temperature electrical conductivities. ESR measurements show a single signal without separating the donor and anion spins, suggesting a pi interaction between the d and pi electrons. For both compounds ferrimagnetic interactions are observed between the nonequivalent donor and anion spins. These materials exhibit bulk canted weak ferromagnetism below 7.6 K for both 1 and 2.
authors.affiliation: LCSIM, UMR 6511 CNRS, Université de Rennes 1, Institut de Chimie de Rennes, 35042 Rennes Cedex, France.
authors.forename: Fatima
authors.initials: F
authors.lastname: Setifi
authors.forename: Stéphane
authors.initials: S
authors.lastname: Golhen
authors.forename: Lahcène
authors.initials: L
authors.lastname: Ouahab
authors.forename: Akira
authors.initials: A
authors.lastname: Miyazaki
authors.forename: Kazuki
authors.initials: K
authors.lastname: Okabe
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Enoki
authors.forename: Takashi
authors.initials: T
authors.lastname: Toita
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Yamada