Structure‐Triggered High Quantum Yield Luminescence and Switchable Dielectric Properties in Manganese(II) Based Hybrid Compounds

Abstract Two new manganese(II) based organic–inorganic hybrid compounds, C 11 H 21 Cl 3 MnN 2 ( 1 ) and C 11 H 22 Cl 4 MnN 2 ( 2 ), with prominent photoluminescence and dielectric properties were synthesized by solvent modulation. Compound 1 with novel trigonal bipyramidal geometry exhibits bright red luminescence with a lifetime of 2.47 ms and high quantum yield of 35.8 %. Compound 2 with tetrahedral geometry displays intense long‐lived (1.54 ms) green light emission with higher quantum yield of 92.3 %, accompanied by reversible solid‐state phase transition at 170 K and a distinct switchable dielectric property. The better performance of 2 results from the structure, including a discrete organic cation moiety and inorganic metal anion framework, which gives the cations large freedom of motion.