Fluorescence Quenching of 2-amino-7-bromofluorene by Chloromethanes – Static and Dynamic Model for CCl 4 Quenching in Polar Solvents

Abstract

The study of fluorescence quenching of 2-amino-7-bromofluorene (ABF) by chloromethanes (CH₂Cl₂, CHCl₃, CCl₄) in various solvents reveals that (i) the quenching constant k_q depends on solvent viscosity for CCl₄ and on solvent polarity for CH₂Cl₂ and CHCl₃; (ii) the observed positive deviation in methanol and acetonitrile in the Stern–Volmer plot is due to the presence of a static component in quenching; (iii) the fluorescence quenching is mainly due to the formation of a non-emissive charge transfer complex in the excited state.