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Quinine (and quinidine) are used as the chiral moiety for the ligands used in Sharpless asymmetric dihydroxylation as well as for numerous other chiral catalyst backbones. Because of its relatively constant and well-known fluorescence quantum yield, quinine is used in photochemistry as a common fluorescence standard. [33] [34]
The chloride ion is a well known quencher for quinine fluorescence. [2] [3] [4] Quenching poses a problem for non-instant spectroscopic methods, such as laser-induced fluorescence. Quenching is made use of in optode sensors; for instance the quenching effect of oxygen on certain ruthenium complexes allows the measurement of oxygen saturation in ...
Fluorescence quantum yields are measured by comparison to a standard of known quantum yield. [2] The quinine salt quinine sulfate in a sulfuric acid solution was regarded as the most common fluorescence standard, [ 3 ] however, a recent study revealed that the fluorescence quantum yield of this solution is strongly affected by the temperature ...
The quinine salt quinine sulfate in a sulfuric acid solution was regarded as the most common fluorescence standard, [17] however, a recent study revealed that the fluorescence quantum yield of this solution is strongly affected by the temperature, and should no longer be used as the standard solution.
The quinine in tonic water will fluoresce under ultraviolet light. In fact, quinine will visibly fluoresce in direct sunlight against a dark background. [19] The quinine molecules release energy as light instead of heat, which is more common. The state is not stable, and the molecules will eventually return to a ground state and no longer glow ...
Fluorescence of different substances under UV light. Green is a fluorescein, red is Rhodamine B, yellow is Rhodamine 6G, blue is quinine, purple is a mixture of quinine and rhodamine 6g. Solutions are about 0.001% concentration in water.
Processes such as fluorescence and phosphorescence are examples of intramolecular deactivation processes. An intermolecular deactivation is where the presence of another chemical species can accelerate the decay rate of a chemical in its excited state. In general, this process can be represented by a simple equation:
A classic example of this process is the quinine sulfate fluorescence, which can be quenched by the use of various halide salts. [citation needed] The excited molecule can de-excite by increasing the thermal energy of the surrounding solvated ions. Several natural molecules perform a fast internal conversion.