Zero-DimensionalPlastic Phase Transition Iron-BasedCompounds with High <i>T</i>_c and SwitchableSHG Responses

Organic–inorganic hybrid materials have garnered significant interest due to their unique combination of phase transition characteristics, substantial entropy changes, simple preparation methods, and structural flexibility, making them promising candidates for applications in sensor technologies and data storage systems. In the present research, two plastic organic–inorganic hybrid phase transition materials: [C₇H₁₇NF]­FeCl₄ (<b>1</b>) and [C₇H₁₇NF]­FeBr₄ (<b>2</b>) were successfully synthesized by the H/F substitution strategy. Significant step-like dielectric changes were observed during the reversible phase transitions of <b>1</b> (401 K) and <b>2</b> (406 K). At the same time, <b>1</b> and <b>2</b> have flexible switchable SHG effects and show the characteristics of band gap semiconductors with band gaps of 2.44 and 2.08 eV, respectively. This research presents an efficacious approach for devising the structures and modulating the properties of organic–inorganic hybrid materials.