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)MnCl 3 ·CH 3 OH (MBA = C 6 H 5 CH(CH 3 )NH 3 + ) and (R/S‐NPA)Cl·H 2 O and (R, S‐NPA)Cl (NPA = C 10 H 7 CH(CH 3 )NH 3 + ) single crystals are successfully obtained using methanol (CH 3 OH) as an induced‐crystallization reagent by slow evaporation method. Interestingly, (R/S‐MBA)MnCl 3 ·CH 3 OH single crystals with obvious circular dichroism (CD) characteristics exhibit the strong red emission characteristics originating from the d‐d transition of Mn 2+ cation, while (R/S‐NPA) Cl·H 2 O and (R, S‐NPA)Cl exhibit blue emission originating from the organic NPA group. Based on their chiral space group P 2 1 (no.4), (R/S‐MBA)MnCl 3 ·CH 3 OH single crystals show excellent circularly polarized luminescence (CPL) with a relatively high luminescence dissymmetry factor ( g lum ) value, which is equivalent to that of reported Mn (II)‐based metal halides. Also, (R/S‐NPA)Cl·H 2 O and (R/S‐MBA)MnCl 3 ·CH 3 OH 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.