Benzothiazolinic Spiropyran to Merocyanine Photo-switching: a TD-DFT study

Benzothiazolinic spiropyran containing a methoxy group at ortho position as well as NO2 group para to the phenolic oxygen atom was used to investigate the photo-switching process. The photophysical properties and relative energies were explored at CAM-B3LYP/6-31G(d) level of theory. As observed, the process of switching in the excited state is faster than the ground state because of the lower energy barrier in the excited state. A red shift of 549.5 nm in fluorescence emission with oscillator strength of 0.571 was found for photo-switched merocyanine.

Keywords:

Benzothiazolinic spiropyrans , Photo-switching , TD-DFT