title: Anisotropic Change in the Magnetic Susceptibility of a Dynamic Single Crystal of a Cobalt(II) Complex.
abstract: Atypically anisotropic and large changes in magnetic susceptibility, along with a change in crystalline shape, were observed in a CoIIcomplex at near room temperature. This was achieved by combining oxalate molecules, acting as rotor, and a CoIIion with unquenched orbital angular momentum. A thermally controlled 90° rotation of the oxalate counter anion triggered a symmetry-breaking ferroelastic phase transition, accompanied by contraction-expansion behavior (ca. 4.5 %) along the long axis of a rod-like single crystal. The molecular rotation induced a minute variation in the coordination geometry around the CoIIion, resulting in an abrupt decrease and a remarkable increase in magnetic susceptibility along the direction perpendicular and parallel to the long axis of the crystal, respectively. Theoretical calculations suggested that such an unusual anisotropic change in magnetic susceptibility was due to a substantial reorientation of magnetic anisotropy induced by slight disruption in the ideal D3coordination environment of the complex cation.
authors.affiliation: Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, 744 Motooka Nishi-ku, 819-0395, Fukuoka, Japan.
authors.forename: Zi-Shuo
authors.initials: ZS
authors.lastname: Yao
authors.affiliation: Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, 744 Motooka Nishi-ku, 819-0395, Fukuoka, Japan.
authors.forename: Shu-Qi
authors.initials: SQ
authors.lastname: Wu
authors.affiliation: Division of Chemical Engineering, Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, 1-3, Machikaneyama, Toyonaka, Osaka, 560-8531, Japan.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Kitagawa
authors.affiliation: Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, 744 Motooka Nishi-ku, 819-0395, Fukuoka, Japan.
authors.forename: Sheng-Qun
authors.initials: SQ
authors.lastname: Su
authors.affiliation: Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, 744 Motooka Nishi-ku, 819-0395, Fukuoka, Japan.
authors.forename: You-Gui
authors.initials: YG
authors.lastname: Huang
authors.affiliation: Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, 744 Motooka Nishi-ku, 819-0395, Fukuoka, Japan.
authors.forename: Guo-Ling
authors.initials: GL
authors.lastname: Li
authors.affiliation: School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, 221116, P.R. China.
authors.forename: Zhong-Hai
authors.initials: ZH
authors.lastname: Ni
authors.affiliation: Institute for Materials Research, Tohoku University, Katahira 2-1-1, Sendai, 980-8577, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nojiri
authors.affiliation: Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, 744 Motooka Nishi-ku, 819-0395, Fukuoka, Japan.
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Shiota
authors.affiliation: Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, 744 Motooka Nishi-ku, 819-0395, Fukuoka, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Yoshizawa
authors.affiliation: Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, 744 Motooka Nishi-ku, 819-0395, Fukuoka, Japan.
authors.forename: Soonchul
authors.initials: S
authors.lastname: Kang
authors.affiliation: Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, 744 Motooka Nishi-ku, 819-0395, Fukuoka, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Kanegawa
authors.affiliation: Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, 744 Motooka Nishi-ku, 819-0395, Fukuoka, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Sato
keywords: cobalt; magnetic switching; phase transitions; shape change; symmetry breaking