Organic Cation-Directed Modulation of Emissions in Zero-Dimensional Hybrid Tin Bromides.

Zero-dimensional hybrid metal halides (0D HMHs) are attractive due to their intriguing self-trapped exciton (STE) emission properties. However, the effect of organic cations on the emission of 0D HMHs is relatively underexplored. Herein, we report two types of 0D hybrid tin bromides, (BMe)SnBr (BMe = CNH) and (MeH)SnBr (MeH = CNH), which share similar structural features with different hydrogen bonding (HB) interactions between [SnBr] anions and organic cations. The (BMe)SnBr with weak HB interactions exhibits only STE emission, while the (MeH)SnBr exhibits both STE and charge transfer exciton emissions owing to the strong HB interactions, resulting in an excitation-dependent emission at cryogenic conditions. Detailed structural analyses and Hirshfeld surface calculations confirm that the enhanced HB interactions are essential to obtain the multiple emissions in (MeH)SnBr.