Melt-Processable Zero-Dimensional Mn Hybrid Metal Halides

Leveraging phase transitions in hybrid metal halides offers broad opportunities for creating programmable, dynamic materials. Here, we report a new family of meltable zero-dimensional Mn²⁺ hybrid metal halides containing oligo-ethylene glycolammonium cations that exhibit bright green emission and exceptionally low melting points near 55 °C. By varying the length of oligo-ethylene glycol ammonium cations, we tune thermodynamic and optoelectronic properties, linking molecular design with phase stability and optoelectronic properties. Temperature-dependent X-ray diffraction and photoluminescence measurements show that melting leads to a substantial reduction of emission in the molten phase. These results establish oligo-ethylene glycol ammonium cations as an effective strategy for engineering low-melting-point, phase-reconfigurable hybrid metal halides. More broadly, this work demonstrates a pathway toward melt-processable and thermally responsive hybrid semiconductors, with potential applications in sustainable materials processing and adaptive optoelectronic technologies.