Crosslinkable Zero‐Dimensional Organic Metal Halide Hybrids for Insoluble and Robust Films

ABSTRACT Zero‐dimensional (0D) organic metal halide hybrids (OMHHs) offer highly tunable properties for optoelectronics and radiation detection, but are limited by poor stability in polar environments due to their ionic nature. Here, we report the first demonstration of crosslinkable 0D OMHHs that enable the formation of insoluble and robust films via photocrosslinking. By reacting a vinyl‐functionalized organic chloride salt, diphenyl(4‐vinylbenzyl)(4‐vinylphenyl)phosphonium chloride (DPVBVPPCl), with antimony(III) chloride (SbCl 3 ), we obtained an amorphous 0D OMHH, (DPVBVPP) 2 SbCl 5 , with excellent film‐forming capability and moldability. Upon UV irradiation, the pendant vinyl groups undergo efficient crosslinking to yield an insoluble hybrid network, (CP‐DPVBVPP)(SbCl 5 ) n . The crosslinked films retain bright orange photoluminescence and radioluminescence (∼645 nm), indicating preservation of the SbCl 5 2− emissive centers, while exhibiting dramatically enhanced water resistance and improved thermal decomposition stability. This work introduces a molecular design strategy for incorporating crosslinkable organic cations into 0D OMHHs, providing a versatile platform for robust functional hybrid materials for practical applications.