The effect of substituents and polymer media on photochromism kinetics of indolinospironaphthoxazine

The effect of substituents in indoline moiety and polymer media on photochromism and thermal decay processes of spirooxazine (ASP) was investigated. The thermal decoloration rate was decreased with increasing steric hindrance of substituents in l-position of indoline moiety. The stability of the colored forms was improved when the hydrogen in the 5-position of indoline moiety was replaced with electron-donating groups and was decreased when substituted by electron-withdrawing groups. In addition, the stability of the colored forms was related to properties of polymer media. The thermal decay rate decreased with an increase in the polarity and rigidity of polymer media. The themal decay kinetics of the colored forms obeyed biexponential decay law.

The effect of substituents in indoline moiety and polymer media on photochromism and thermal decay processes of spirooxazine (ASP) was investigated. The thermal decoloration rate was decreased with increasing steric hindrance of substituents in I-position of indoline moiety. The stability of the colored forms was improved when the hydrogen in the 5-position of indoline moiety was replaced with electron-donating groups and was decreased when substituted by electron-withdrawing groups. In addition, the stability of the colored forms was related to properties of polymer media. The thermal decay rate decreased with an increase in the polarity and rigidity of polymer media. The themal decay kinetics of the colored forms obeyed biexponential decay law.