Proton order-disorder phenomena in a hydrogen-bonded rhodium--semiquinone complex; A Possible dielectric response mechanism

水素結合系ロジウム--セミキノン錯体におけるプロトン秩序-無秩序化転移

満身 稔*; 江崎 一成*; 小松 裕貴*; 鳥海 幸四郎*; 宮東 達也*; 水野 元裕*; 東 信晃*; 宮崎 裕司*; 中野 元裕*; 北河 康隆*; 花島 隆泰*; 鬼柳 亮嗣  ; 大原 高志   ; 中筋 一弘*

Mitsumi, Minoru*; Ezaki, Kazunari*; Komatsu, Yuki*; Toriumi, Koshiro*; Miyato, Tatsuya*; Mizuno, Motohiro*; Azuma, Nobuaki*; Miyazaki, Yuji*; Nakano, Motohiro*; Kitagawa, Yasutaka*; Hanashima, Takayasu*; Kiyanagi, Ryoji; Ohara, Takashi; Nakasuji, Kazuhiro*

A newly synthesized one-dimensional (1D) hydrogen-bonded (H-bonded) rhodium(II)--semiquinone complex, [CpRh(--HSQ-Me)]PF exhibits a paraelectric-;antiferroelectric second-order phase transition at 237.1 K. Neutron and X-ray crystal structure analyses reveal that the H-bonded proton is disordered over two sites in the room-temperature (RT) phase. The phase transition would arise from this proton disorder together with rotation or libration of the Cp ring and PF ion. The relative permittivity ' along the H-bonded chains reaches relatively high values (ca., 130) in the RT phase.