title: The magnetoresistance effect in a conducting molecular crystal consisting of dicyano(phthalocyaninato)manganese(iii).
abstract: A conducting molecular crystal TPP[MnIII(Pc)(CN)2]2(MnIII: d4, S = 1, TPP = tetraphenylphosphonium and Pc = phthalocyanine) was fabricated. In its crystal structure, the [MnIII(Pc)(CN)2] units formed a one-dimensional regular chain along the c-axis with an overlap integral value of 8.6 × 10-3. TPP[MnIII(Pc)(CN)2]2showed a semiconducting behaviour that also has been observed for isostructural TPP[CoIII(Pc)(CN)2]2(CoIII: d6, S = 0) and TPP[FeIII(Pc)(CN)2]2(FeIII: d5, S = 1/2) whose ground states are charge-ordered states. In spite of the local magnetic moment of the MnIIIion (S = 1) at the centre of the Pc ligand, TPP[MnIII(Pc)(CN)2]2exhibited an almost isotropic and small negative magnetoresistance (MR) effect (the MR ratio was -8.7% under 8 T at 10.7 K), contrarily to the anisotropic giant negative MR effect of TPP[FeIII(Pc)(CN)2]2. The isotropy was found to be due to a (dxz)1(dyz)1electronic configuration, and the smaller MR effect was explained by a weaker antiferromagnetic interaction between MnIIIions than that between FeIIIions, as suggested by a Weiss temperature Θ of -3.1 K (|Jdd|/kB= 1.2 K).
authors.affiliation: Institute for Solid State Physics, the University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8581, Japan.
authors.forename: Masaki
authors.identifier: http://orcid.org/0000-0001-9357-1133
authors.initials: M
authors.lastname: Matsuda
authors.affiliation: Institute for Solid State Physics, the University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8581, Japan.
authors.forename: Gosuke
authors.initials: G
authors.lastname: Yoshida
authors.affiliation: Institute for Solid State Physics, the University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8581, Japan.
authors.forename: Jun-Ichi
authors.initials: JI
authors.lastname: Yamaura
authors.affiliation: Department of Chemistry, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810, Japan.
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Inabe
authors.affiliation: Institute for Solid State Physics, the University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8581, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tajima