We synthesized 3′,3′-dimethyl-1′-octadecyl-6-nitrospiro- [2H-1-benzopyran-2,2′-indoline] (SP-18) and examined its photochromic behavior and fluorescence in the presence of acid. When strong acids such as HCl and dodecylbenzene-sulfonic acid (DBSA) were present, the merocyanine (MC) form generated via heterolytic cleavage of oxygen-carbon bond of the spiropyran (SP) by the irradiation of UV light was protonated to produce the complex MCH +. The MCH+ had a yellow color with the absorption maxima at between 410-430 nm. Since ring-closing reaction of the MC form to produce the SP form was retarded by the protonation of the phenolate in the MC form, MCH+ had better stability than the MC. Emission peak of the MCH + form was observed at 645 nm with HCl and 600 nm with DBSA, respectively. Polymethylmethacrylate (PMMA) films containing the MCH+ retained about 75% of its original absorbance even after 48h.
|Journal||Molecular Crystals and Liquid Crystals Science and Technology Section A: Molecular Crystals and Liquid Crystals|
|Issue number||PART 2|
|Publication status||Published - 2003 Dec 1|
|Event||Proceedings of the 13th Korea-Japan Joint Forum on Organic Materials for Electronics and Photonics - Sendai, Japan|
Duration: 2002 Oct 22 → 2002 Oct 24
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics