Order–Disorder Phase Transitions and Topological Isomerization in a Ternary-Ligand Synergistic Coordination Network

作者：Shang Chen, Ting Xu, Liu T, T T Wang, Zhao‐Quan Yao, Jiong‐Peng Zhao, Fu‐Chen Liu · 发表于：Inorganic Chemistry · 年份：2026 · DOI：10.1021/acs.inorgchem.6c01245 · 研究领域：Metal-Organic Frameworks: Synthesis and Applications、Magnetism in coordination complexes、Zeolite Catalysis and Synthesis

Recently, supramolecular isomers obtained by single-crystal-to-single-crystal (SCSC) transformations have emerged as a significant research focus but are rarely reported. To address this, a lon topological complex, [H 2 DABCO][Fe II 2 (C 2 O 4 )(HCOO) 2 Cl 2 ]·H 2 O ( 1 ), was synthesized with a cation dynamics nature, in which the [H 2 DABCO] 2+ underwent an order–disorder transition on heating at about 210 K, accompanied by significant dielectric anomalies. Upon further heating above 413 K, 1 undergoes an intriguing SCSC transformation to the anhydrous phase [H 2 DABCO][Fe II 2 (C 2 O 4 )(HCOO) 2 Cl 2 ] ( 2 ), retaining the original coordination geometry of the metal ions and ligands but revealing the zeolite crb net. This supramolecular network isomerization is extremely rare during the single-crystal-to-single-crystal transformation. Besides, the isomerization of the topological network influences the structural phase transitions and magnetic properties of 1 and 2 . In 2, the organic ammonium ions remain disordered below 100 K without further structural phase transitions. Magnetic studies further reveal that 1 is an antiferromagnet with an ordering temperature of 25 K and exhibits canting at 15 K, while in 2, no significant spin canting was observed.