title: (Nitronyl nitroxide)-substituted trioxytriphenylamine radical cation tetrachlorogallate salt: a 2p-electron-based weak ferromagnet composed of a triplet diradical cation.
abstract: The synthesis and the solid state magnetic properties of (nitronyl nitroxide)-substituted trioxytriphenylamine radical cation tetrachlorogallate, NNTOT(+)⋅GaCl(4)(-), are reported. In the temperature region between 300 and 3 K, the magnetic behavior is characterized by the strong intramolecular ferromagnetic interaction (J/k(B)=+400 K) between the radical (NN) and the radical cation (TOT(+)) and the weak intermolecular antiferromagnetic interaction (J/k(B)=-1.9 K) between NNTOT(+) ions. Below 3 K, a 3D-type long-range magnetic ordering into a weak ferromagnet was observed (T(N)=2.65 K). The magnetic entropy (S(mag)=8.97 J K(-1)  mol(-1)) obtained by the heat capacity measurement is in good agreement with the theoretical value of R ln3=9.13 J K(-1)  mol(-1) based on the S=1 state.
authors.affiliation: Department of Chemistry, Graduate School of Science, Osaka City University, Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Kuratsu
authors.forename: Shuichi
authors.initials: S
authors.lastname: Suzuki
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Kozaki
authors.forename: Daisuke
authors.initials: D
authors.lastname: Shiomi
authors.forename: Kazunobu
authors.initials: K
authors.lastname: Sato
authors.forename: Takeji
authors.initials: T
authors.lastname: Takui
authors.forename: Tsuneki
authors.initials: T
authors.lastname: Kanzawa
authors.forename: Yuko
authors.initials: Y
authors.lastname: Hosokoshi
authors.forename: Xiao-Zheng
authors.initials: XZ
authors.lastname: Lan
authors.forename: Yuji
authors.initials: Y
authors.lastname: Miyazaki
authors.forename: Akira
authors.initials: A
authors.lastname: Inaba
authors.forename: Keiji
authors.initials: K
authors.lastname: Okada