Excited state pK*a values of naphthylamines: proton-induced fluorescence quenching

✍ Scribed by Kinzo Tsutsumi; Haruo Shizuka

• Publisher: Elsevier Science
• Year: 1977
• Tongue: English
• Weight: 390 KB
• Volume: 52
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(77)80491-0

✦ Synopsis

The dynamic bahavior of the excited singlet of naphthylamines involving proton-induced quenching in a sulfulic acidwater mixture has been studied by means of fluorometry and nanosecond time resolved spectroscopy. A significant tluorcsceace quenching of neutral (Y-and b-naphthylamines induced by protons was observed: 'k q = 8.9 (20.3) X 10' M-' s-l and Ikq = 3.3 (kO.2) X lo8 M-' s-l at 300 K, respectively. On the basis of kinetic analyses. the corrected values of pK,* were determined fo be -1.0 (20.2) and -0.8 (kO.1) for Q-and p-amines, respectively.

The isotope effect on the quenching was also examined.