EMISSION AND NMR SPECTROSCOPIC EVIDENCE TO FLUORESCEIN METHYL-ETHER METHYL-ESTER ENANTIOPIC ISOMERS


Iclı S., Alp S.

TURKISH JOURNAL OF CHEMISTRY, vol.19, no.3, pp.188-195, 1995 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 19 Issue: 3
  • Publication Date: 1995
  • Journal Name: TURKISH JOURNAL OF CHEMISTRY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED)
  • Page Numbers: pp.188-195
  • Dokuz Eylül University Affiliated: Yes

Abstract

The synthesized methyl ether methyl ester of fluorescein is separated into enantiotopic isomers on a triacetylcellulose chromatography column. The same isomers are also detected on carbon-13 NMR spectra. The ratio of isomers is found to be 4:1. The emission of fluorescein is enhanced fourfold at -196 degrees C in respects to 24 degrees C. It is estimated that the through space pi - pi interactions between the plane of fused rings and the o-benzoylate carboxyl group at more stable isomer configurations are the cause of emission enhancements at low temperatures.