Vitrification and Cold Crystallization of a One-Dimensional Perovskite-like Compound Enabled by Reorganizable Coordination Bonds and a Configurationally Restricted Cation

Understanding glass formation and transformation remains a fundamental challenge in materials science. Here, we report the first example of vitrification and multifactor-triggered cold crystallization in a one-dimensional (1D) perovskite-like coordination polymer, (4-methylmorpholinium)[Cd(SCN)3]. By introducing cleavable and reorganizable Cd–S/N coordination bonds, we enable glass formation via melt-quenching, a process previously unachievable in 1D perovskite-like compounds. Comprehensive structural and spectroscopic analyses as well as molecular dynamics simulations, especially in-depth solid-state NMR analysis, reveal that reversible coordination bond reorganization and the restricted configurational freedom of the methylmorpholinium cation drive the glass–crystal transition. Combined dynamic and isothermal DSC studies demonstrate that cold crystallization proceeds via instantaneous nucleation and 1D crystal growth, driven by the confined rearrangement of the 4-methylmorpholinium cation. These findings establish a new vitrification mechanism based on dynamic coordination bonds, providing molecular-level insight into phase transitions in low-dimensional hybrid organic–inorganic perovskites or perovskite-like compounds and offering new strategies for glass-forming hybrid materials.