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

Iclı S., Alp S.

TURKISH JOURNAL OF CHEMISTRY, cilt.19, sa.3, ss.188-195, 1995 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 19 Sayı: 3
  • Basım Tarihi: 1995
  • Dergi Adı: TURKISH JOURNAL OF CHEMISTRY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED)
  • Sayfa Sayıları: ss.188-195
  • Dokuz Eylül Üniversitesi Adresli: Evet

Özet

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.