Meng-Ling Wu†, Jun-Hui Liang†, Yan-Ru Chen, Kang Chen, Ze-Yu Ruan, Si-Guo Wu*, Wei-Zhao Cai*, Ming-Liang Tong*

Cite this article: Chin. J. Struct. Chem., 2026, 45(8), 100941. DOI: 10.1016/j.cjsc.2026.100941

Publication date: August 1, 2026

Keywords: Spin crossover; Pressure; Symmetry breaking; Stimuli-responsive; Spin-state regulation

ABSTRACT

The exploration of structural evolutions in dynamic crystals under multiple stimuli is of high interest. Herein, we develop a cyanide-bridged bimetallic coordination polymer [Fe{Ag(CN)2}2(imipz)] (1-Fe, imipz = imidazo[1,2-a]pyrazine) featuring one-dimensional zigzag Ag chains with argentophilic interactions. 1-Fe exhibits an incomplete spin-crossover (SCO) behavior with a hysteresis loop of 19 K. Notably, temperature and pressure drive distinct crystal evolution pathways that lead to divergent spin-state regulation. Under thermal annealing, the intermediate spin-state is achieved mainly through the deflection of the imipz ligand and leads to the formation of non-equivalent SCO-active centers. Under hydrostatic compression, Ag−CN−Fe linkages undergo significant structural deformations, resulting in enhanced argentophilic interactions and anisotropic compressibility in the lattice. Concomitantly, a reversible pressure-induced electronic configuration modulation occurs, transitioning from a high-spin to a low-spin state accompanied by an isostructural phase transition. These results highlighted in this work elucidate the stimuli-responsive mechanisms for spin-state trapping via dynamic structural deformations, and provide a novel perspective for the design of addressable functional crystals.