A novel fluorescent pH indicator for the acidic range.
Reaction of a commercial preparation of lissamine-rhodamine B sulfonyl chloride with primary amines gives rise to two sulfonamide derivatives, of which one behaves as a pH indicator with maximal fluorescence emission in the acidic range and a pKa of about 4.6. The structure of this derivative and the mechanism of fluorescence dependence on pH, elucidated by means of NMR, is presented.
Marchesini
S
S
Department of Biomedical Sciences and Biotechnology, University of Brescia, Italy.
Gatt
S
S
Agmon
V
V
Giudici
M L
ML
Monti
E
E
D000143:Acids; D000588:Amines; D006863:Hydrogen-Ion Concentration; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D012235:Rhodamines; D013050:Spectrometry, Fluorescence
D000143:Acids; D000588:Amines; D012235:Rhodamines; C022027:lissamine rhodamine B