Thermo- and photochromic dyes: indolino-benzospiropyrans. Part 1. UV–VIS spectroscopic studies of 1,3,3-spiro(2 H -1-benzopyran-2,2′-indolines) and the open-chain merocyanine forms; solvatochromism and medium effects on spiro ring formation

Thermo- and photochromic dyes: Spiro(ind

Thermo- and photochromic dyes: Spiro(indolinebenzopyrans). 2—detailed assignment of the 1H NMR spectra and structural aspects of the closed form of 1,3,3-trimethylspiro(indoline-2,2′-benzopyrans)

✍ Sam-Rok Keum; Ki-Bong Lee; Peter M. Kazmaier; Richard A. Manderville; Erwin Bunc 📂 Article 📅 1992 🏛 John Wiley and Sons 🌐 English ⚖ 344 KB

## Abstract The proton NMR assignments for a series of 12 thermo‐ and photochromic 1,3,3‐trimethylspiro(indoline‐2,2′‐benzopyrans) dyes is reported. All of the protons in the dye molecule were assigned through a combination of homonuclear decoupling experiments and correlation spectroscopy. The rel