Solvent-free room-temperature synthesis of brightly luminescent [BMPyr] 2 [SnCl 4 ].

The pseudo-ternary tin(II) halide [BMPyr] 2 [SnCl 4 ] can be obtained just by mixing the starting materials [BMPyr]Cl and SnCl 2 at room temperature without additional solvents. The compound shows bright Sn(II)-based emission of deep-red light ( λ max : 740 nm) with a quantum yield of 88 ± 3% after optimised synthesis. Characterization is performed by X-ray structure analysis, infrared and fluorescence spectroscopy. Exemplary fluorescent thinfilms are realized by solvent processing.