查看文章

The carbazole ring is the basic structure present in the fluorescence derivatization reagents 9‐chlorocarbonylcarbazole and 9‐carbazolylacetic acid. The fluorescence behaviour of these carbazole derivatives was studied in solvents with different polarities (cyclohexane, ethanol, acetonitrile, water) and at different pH values (4.5 and 8.8). The influence of the low polarity environment afforded by 2‐hydroxypropyl‐β‐cyclodextrin (HPβ‐CD) is also described. The behaviour of the fluorescent reagents is compared to the model molecules carbazole and 9‐methylcarbazole. For all derivatives studied, a bathochromic shift in the fluorescence emission maxima was observed when the solvent polarity was increased. A bathochromic shift was observed in dioxane solutions, which can be ascribed to the peculiar behaviour of this solvent. The changes in the fluorescence intensity in the case of 9‐carbazolylacetic acid can be …