Strong Magneto‐chiroptical Effects through Introducing Chiral Transition‐metal Complex Cations to Lead Halide

The interplay between chirality with magnetism can break both the space and time inversion symmetry and have wide applications in information storage, photodetectors, multiferroics and spintronics. Herein, we report the chiral transition‐metal complex cation‐based lead halide, R‐CDPB and S‐CDPB. In contrast with the traditional chiral metal halides with organic cations, a novel strategy for chirality transfer from the transition‐metal complex cation to the lead halide framework is developed. The chiral complex cations directly participate the band structure and introduce the d‐d transitions and tunable magneto‐chiroptical effects in both the ultraviolet and full visible range into R‐CDPB and S‐CDPB. Most importantly, the coupling between magnetic moment of the complex cation and chiroptical properties is confirmed by the magneto‐chiral dichroism. For the band‐edge transition, the unprecedented modulation of +514% for S‐CDPB and ‐474% for R‐CDPB was achieved at ‐1.3 Tesla. Our findings demonstrate a novel strategy to combine chirality with magnetic moment, and provide a versatile material platform towards magneto‐chiroptical and chiro‐spintronic applications.