Rapid synthesis of two photoluminescent pyridinium manganese-based halides by an anti-solvent method

The zero-dimensional Mn2+-based halides have efficient emission and good stability due to their unique crystal and electronic structures. Herein, a rapid anti-solvent method was used to prepare two lead-free manganese-based metal halides, (PP)3MnBr5 and (CP)2MnBr4, where PPB (1-phenacylpyridinium bromide) and CPB (cetylpyridinium bromide) were used as organic ion sources. Single crystal of (PP)3MnBr5 was grown and its structure was solved by XRD. In both compounds, (MnBr4)2- is isolated by organic molecules to form a 0-dimensional structures, exhibiting different fluorescent thermal stability and photoluminescence lifetimes. (PP)3MnBr5 shows a strong narrow emission band at 510 nm with a high photoluminescence quantum yield of 73 % and high environmental and thermal stability. (CP)2MnBr4 has a yellow-green emission band at 525 nm with a photoluminescence quantum yield of 28 %. (PP)3MnBr5 has a higher atmosphere and thermal stability than (CP)2MnBr4. After exposure in air for 1000 h, the luminescence intensity of (PP)3MnBr5 is 95 % of the initial value. At 423.15 K, the luminescence intensity of (PP)3MnBr5 is 79 % of the initial value.