Structural isomerization and cold crystallization of bis[1-(2-propyl)iminomethylnaphthalen-2-olato]nickel(II) by thermal analysis, x-ray diffraction, and FT-IR

Abstract

Two coordination isomers, i.e., square planar and pseudo-tetrahedral forms of the title compound, were crystal-lographically identified and discussed in relation to their thermal behavior revealed by XRD-DSC and FTIR-DSC. Upon the fusion, the coordination geometry partly changes, resulting in the liquid, which is an equilibrium mixture of molecules with the two coordination geometries. In this system, the mixed nature of liquid, in addition to molecular flexibility, is responsible for realization of large supercooling and glass transition, both of which enables the cold crystallization.