Methanol‐Induced Crystallization of Chiral Hybrid Manganese (II) Chloride Single Crystals for Achieving Circularly Polarized Luminescence and Second Harmonic Generation

Abstract

Chiral hybrid Mn (II)‐based halides have attracted great interest in the optoelectronic field due to their low cost, non‐toxicity, abundant structural diversity, and excellent photoluminescence, chiroptical, and nonlinear optical characteristics. Here, chiral hybrids (R/S‐MBA)MnCl3·CH3OH (MBA = C6H5CH(CH3)NH3+) and (R/S‐NPA)Cl·H2O and (R, S‐NPA)Cl (NPA = C10H7CH(CH3)NH3+) single crystals are successfully obtained using methanol (CH3OH) as an induced‐crystallization reagent by slow evaporation method. Interestingly, (R/S‐MBA)MnCl3·CH3OH single crystals with obvious circular dichroism (CD) characteristics exhibit the strong red emission characteristics originating from the d‐d transition of Mn2+ cation, while (R/S‐NPA) Cl·H2O and (R, S‐NPA)Cl exhibit blue emission originating from the organic NPA group. Based on their chiral space group P21 (no.4), (R/S‐MBA)MnCl3·CH3OH single crystals show excellent circularly polarized luminescence (CPL) with a relatively high luminescence dissymmetry factor (glum) value, which is equivalent to that of reported Mn (II)‐based metal halides. Also, (R/S‐NPA)Cl·H2O and (R/S‐MBA)MnCl3·CH3OH exhibit the obvious second harmonic generation (SHG) response. This work not only deepens the understanding of the role of methanol‐induced crystallization in improving the quality and growth habits of Mn (II)‐based halide hybrid single crystals, but also provides guidance for further structural design, crystal growth, and optoelectronic applications of multi‐functional chiral hybrid Mn (II)‐based halide materials.