Solvatochromic behavior of non-activated indolinobenzospiropyran 6-carboxylates in aqueous binary solvent mixtures.Part II

摘要

The solvatochromic behavior of non-activated indolinobenzospiropyran 6-carboxylates SP-1-2 in aqueous binary solvent mixtures was investigated.Marked negative solvatochromism was exhibited by SP-1-2 in the whole region of solvent polarity examined.Excellent linear relationships were observed between lambda_(max) and the solvent polarity parameter,E_T(BM),for the aqueous binary solvent mixtures.The sensitivity of the binary solvent system toward the transition energies of the MC form was highest in the water-methanol solvents in all SP molecules examined.As of other merocyanine dyes in neat solvents,the MC form of spiropyran 6-carboxylates in the aqueous binary solvents showed a negative solvatochromism.The aqueous solvent was found to affect the solvatochromic behavior of the merocyanine dyes by increasing the sensitivity of the chromophore to the effects of solvation via H-bonding.