Abstract:

The mechanism of ring closure process of negative photochromic indoline spiropyran is investigated by its UV-visible spectra. The quantum yields of light bleaching process of the colored form in different solvents and with different additives are measured. The results indicate that the oxygen and other triplet quenching agent such as triphcnyladrine have little effect on the decoloration process. The occurrence of the photodecoloration reaction of the system primarily via a singlet channel can be identified.

Key words: Negative photochromism, Indoline spiropran, Quantum yield