Nonlinear Optical Activity of a Chiral Organic-Inorganic ([(NH 3 CH 2 CH 2 ) 3 NH]) 2 [MnBr 5 ]Br 5 Photoluminescent and Piezoelectric Crystal.

The family of Mn-based organic-inorganic hybrids has greatly expanded due to their advantages in applications. They also show superior bright and size-tunable photoluminescence and can be considered a perfect alternative to toxic lead-based compounds. In this work, we present the detailed structural, optical, and electrical characterization of ([(NH 3 CH 2 CH 2 ) 3 NH]) 2 [MnBr 5 ]Br 5 . The title compound exhibits a unique type of inorganic arrangement created by the trigonal bipyramids. It crystallizes in noncentrosymmetric space group R 32, indicating its optical activity, piezoelectricity, and second-order optical nonlinearity proven by the second harmonic of light measurements. The studied crystals exhibit intense photoluminescence originating from the Mn(II) ion 4 T 1 (G) → 6 A 1 transition. The measured lifetime of the photoluminescence emission is ≤1.5 ms, while the measured quantum yield for both powder and crystal samples reaches ∼70%.