Crystal structures and phase transitions in two new hybrid crystals: (Me 3 NCH 2 CH 2 X) 4 [Ni(NCS) 6 ] (X = Cl and Br)

Understanding phase transitions in multi-component crystals is of importance for regulating specified functional materials. Herein, we present two new organic-inorganic hybrid crystals, (Me 3 NCH 2 CH 2 X) 4 [Ni(NCS) 6 ] (X = Cl and Br), revealing distinct phase transitions. Specifically, the Clsubstituted cations weakly interact with discrete inorganic part hence reveal step-wise dynamic changes upon heating, which result in multi-step solid-solid phase transitions ( P 1 over bar -P 2 1 / n -A 2/ a -Cmce ) including a ferroelastic one with a spontaneous strain of 0.0475. Whereas the Br-substituted cations with larger steric effect prevent the solid-solid phase transition but give a solid-liquid phase transition at above 419 K. The present instances well demonstrate the complicity for multi-component crystals arising from the delicate balance established by abundant weak intermolecular interactions, and inspire the design of novel phase-transition materials by judiciously assembling multi-component crystals. (c) 2023 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Automated summary

This paper presents two new organic-inorganic hybrid crystals, which exhibit distinct phase transitions and provide insights into the complicity of multi-component crystals. Understanding these phase transitions is important for the regulation of functional materials.