Ultrasound and solvent-induced reversible chromism in a luminescent chalcogenidostannate

In the presence of water, ultrasound irradiation of black 2 went back to yellow 1 . The reversible ultrasound and solvent-induced chromism has never been observed before.

Compared with yellow 1 , hyperchromism was apparent around 550 nm in the visible absorption spectrum of 2 . The fluorescent properties for 1 and 2 were investigated and the mechanisms were validated by density functional theory calculations on the experimental geometries. In addition, electron paramagnetic resonance spectra of yellow 1 are similar to chromic black 2 in the signal at g = 4.22 and g = 2.19; the signal at g = 2.19 of 2 shows a sharp increase.