A nickel(II) hydrazinium complex showing reversible phase transition, dielectric anomaly and thermochromism

• Published in: Inorganic chemistry communications 2021-08, Vol.130, p.108702, Article 108702
• Main Authors: Wang, Lingyu, Wei, Zhenhong, Rao, Wenjun, You, Xiuli, Liu, Junjie, Liu, Yuanhan, Cai, Hu
• Format: Article
• Language: English
• ISSN: 1387-7003; 1879-0259
• DOI: 10.1016/j.inoche.2021.108702

An octahedral coordinated nickel(II) hydrazinium complex was prepared by reaction of NiCl2 with trimethyl hydrazinium showing reversible phase transition, dielectric anomaly and thermochromism. [Display omitted] •A nickel complex based on hydrazinium exhibits switchable thermochromic properties.•The nickel complex also shows reversible dielectric property and phase change.•The mechanism of thermochromism was explained by single crystal X-ray diffraction. Thermochromism in copper complexes is known, but nickel thermochromic complex materials are less reported. Herein, we synthesized a nickel metal complex [(Me3NNH2)2NiCl4] (1) based on 1,1,1-trimethylhydrazinium iodide and nickel chloride, which exhibited excellent switching properties in terms of dielectric and phase change and thermochromic properties from yellow to blue. Compound 1 was subjected to the variable temperature single crystal X-ray diffraction, and it was found that the crystal space group did not change after the temperature exceeded the phase transition point, so the thermochromism may be caused by the structural phase transition of the compound.