Co-luminescence in a zero-dimensional organic–inorganic hybrid antimony halide with multiple coordination units

Abstract

Zero-dimensional (0D) organic–inorganic hybrid metal halides (OIMHs) containing multiple halometallate species (HMSs) have received extensive attention due to their capability to achieve multifunctional photophysical characteristics. Herein we report a lead-free 0D-OIMH compound, namely [Emim]₈[SbCl₆]₂[SbCl₅] (1, Emim = 1-ethyl-3-methylimidazolium), which is the first crystal containing two distinct mononuclear [SbX_n]³⁻ⁿ units in one single structure. The optical absorption, temperature/excitation-variable photoluminescence (PL) and PL decay were studied. 1 exhibits a broad emission centered at 577 nm, which is analyzed to be a combination of the emissions from [SbCl₆]³⁻ and [SbCl₅]²⁻. The structural effects including Sb⋯Sb distances and polyhedral distortion of [SbX_n]³⁻ⁿ on the PL of antimony-based 0D-OIMHs are discussed in detail. This work would provide guidance for constructing Sb-based 0D OIMHs composed of multiple halometallate species.