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Qualitative Identification of Carboxylic Acids, Boronic Acids, and Amines Using Cruciform Fluorophores
Published on: August 19, 2013
Fluorescence quenching aptitude of carbazole for the detection of nitro-aromatics: a comprehensive experimental
Ruby Ahmed1, Farman Ali1, Mohammad Jane Alam1
1Department of Applied Chemistry, Zakir Hussain College of Engineering and Technology, AMU Aligarh 202002 India farmanfrequent@gmail.com mjalamamu@gmail.com ahmedruby1974@gmail.com abidaliamu4@gmail.com tameemkhan04@gmail.com amusheer4@gmail.com khan.adeel15@gmail.com.
Abstract:
Fluorescence quenching studies of carbazole with nitroaromatics were studied and compared with 2-phenyl-1H-phenanthro[9,10-d]imidazole (M1). Carbazole (CBz) can sense all nitroaromatics, in particular picric acid (PA), whereas M1 responds to the ones having acidic hydrogen. The complex formation constant (K S) and limit of detection (LOD) were measured using the Stern-Volmer plot. Time-resolved fluorescence measurements reveal that quenching is static. We show that the mechanism of quenching involves ground state complex formation. The CBz-PA complex formation involves hydrogen bonding interaction between the N-H group of CBz and nitro group of PA, whereas M1-PA involves proton transfer from hydroxyl group of PA to nitrogen of imidazole in M1.1 The crystal structure of the ground-state complex (CBz-PA), its topology, and Hirshfeld surface analysis are also presented. Combined experimental and quantum chemical studies and wave function analysis were performed to study the non-covalent interactions and their role in charge transfer (CT) in the CBz-PA complex.
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