A deep-red-emission antimony(iii) chloride with dual-cations: extremely large Stokes shift due to high [SbCl6] distortion

Compound [C5mim][Mim]2[SbCl6] (1; [C5mim]+ = 1-pentyl-3-methylimidazolium; [Mim]+ = N-methylimidazolium) with dual cations exhibits the first case of deep-red emission in [SbCl6]3--based 0D OIMHs. Anion distortion due to high disequilibrium of supramolecular interactions is revealed to be responsible for the extremely large Stokes shift of 335 nm and FWHM of 210 nm in the emission.