Luminescent inorganic–organic hybrid with tunable red light emissions by neutral molecule modification.

• Three novel inorganic-organic hybrid materials were synthesized. • Modulating the fluorescent emission by inserting neutral organic molecules. • Their photoluminescence exhibited yellow, red and orange light emission. Various luminescent organic-inorganic metal halide hybrid materials focus on fluorescence modulation. The commonly method to tunes the luminescence is usually via either modifying the structure of the inorganic anionic or the cation moiety. We here show the first time to modulate the fluorescent emission by inserting neutral organic molecules. The synthesis, crystal structure and optical properties of three organic-inorganic hybrids, [HEV][BiCl 5 (1), [MV] 3 [Bi 4 Cl 18 ·[C 16 H 10 (2) and [MV] 3 [Bi 4 Cl 18 ·[C 20 H 12 (3) ([HEV]2+ = N-proton-N′-ethyl-4,4′-bipyridinium, [MV]2+ = N,N′-dimethyl-4,4′-bipyridinium) were demonstrated. The compounds contain MV2+ cations, bismuth (III)-chloro anions and pyrene or perylene molecules achieve fluorescence modulation upon the insertion of neutral molecules. [ABSTRACT FROM AUTHOR]