Hydrogen bond effects on radiationless electronic transitions in xanthene dyes

✍ Scribed by Monique M. Martin

• Publisher: Elsevier Science
• Year: 1975
• Tongue: English
• Weight: 691 KB
• Volume: 35
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(75)85598-9

✦ Synopsis

In~ermolccular hydrogen bonding effects on internal conversion (S12rr So) and intersystem crossinS (SI w ?1 j in 6-hydroxy-9-phenyl-IIuoron and fluorcscein were determined from fluorescence and riplet yield mc~umnents in alkaline solutions of CF+X20H, H20, CH30H, CHJCH~OH, HCONH2, HCON(CHS)~ and CH;SOCHa. Hydrogen bonding betwecn the dye and the solvent leads to a blue-shift of the absorption and fluorescence spectra and to an enhancement of the fluorescence yield: the [riplct yield remains Sma!l in all solvents. It was found that the internal conversion rate constant decrease exponentially when the O-O band energy of the So -Sl transition increase:.