Thermoinduced structural-transformation and luminescent conversion in hybrid manganese halides

We report here the synthesis of hybrid manganese halide crystals, (C4H7N2)MnCl3· H2O and (C4H7N2)2MnCl4, by using the same organic ligand 2-methylimidazole. Upon heating treatment, the red-emissive (C4H7N2)MnCl3· H2O crystal is structurally transformed into green-emissive (C4H7N2)2MnCl4crystalin situ. The crystal structural analysis reveals that the [MnCl5· H2O]3-octahedra chains decompose into mono [MnCl4]2-tetrahedra, accompanied by the departure of H2O molecules. Upon cooling in air or water vapor, the crystal structure and luminescence of (C4H7N2)2MnCl4are transformed to those of (C4H7N2)MnCl3· H2O. Thein situconversion of luminescence between (C4H7N2)MnCl3· H2O and (C4H7N2)2MnCl4provides new insight into the potential application of hybrid manganese halides.