Room Temperature Phosphorescence in Chiral 0D Zn(II) Metal Halide Crystals for Multiple Anti-Counterfeiting

The development of metal halides that enable multiple information storage and cryptographic security is highly desirable but remains a challenge. Here, a pair of 0D Zn(II) metal halide enantiomers ZnCl2 center dot R/S-2-MP with excitation wavelength-dependent emission and room temperature phosphorescence properties are reported. Organic ligands via NH center dot center dot center dot Cl hydrogen bonding induce structural chirality. In order to stabilize the triplet state exciton and achieve excellent photophysical properties, the organic ligands combine with halogens to promote emission. The differences between the photophysical properties of ZnCl2 center dot R-2-MP and ZnCl2 center dot S-2-MP are analyzed in depth. Furthermore, combined with femtosecond transient absorption (fs-TA) results, the long phosphorescence lifetimes may originate from the triplet state emission due to the synergistic effect between the organic components and the inorganic metal halides. The design strategy of advanced multiple anticounterfeiting technology is further extended. Two 0D chiral excitation wavelength-dependent zinc(II) metal halides are developed that exhibit blue fluorescence and persistent yellow-green phosphorescence. Organic ligands combine with halogens to promote emission. The long phosphorescence lifetimes may originate from the triplet state emission due to the synergistic effect between the organic components and the inorganic metal halides.image