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 ‐R Keum, Ki Bong Lee, Peter M. Kazmaier, Richard A. Manderville, Erwin Buncel

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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 relative stereochemistry of the indolino gem‐dimethyl groups was assigned so that, for the S‐epimer, the pro‐R methyl was found to resonate at 1.24 ppm while the pro‐S methyl appeared at 1.37 ppm for compound 1.

Original languageEnglish
Pages (from-to)1128-1131
Number of pages4
JournalMagnetic Resonance in Chemistry
Issue number11
Publication statusPublished - 1992



  • H NMR assignments
  • Spiro(indoline‐2,2′‐benzopyrans)
  • Thermo‐ and photochromic dyes

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)

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