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

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*; et al.

Chemistry; A European Journal, 21(27), p.9682 - 9696, 2015/06

https://doi.org/10.1002/chem.201500796

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.