Fluorescence quenching of anthracene by aniline in two solvents: S-V plot analysis

摘要

Quenching measurements can reveal the accessibility of fluorophores to quenchers. Our study reveals the exact reason of quenching of molecule and explains about the ground state complex. In an ambient temperature the fluorescence quenching of anthracene by aniline in two different solvents namely cyclohexane and toluene was studied. Herein, The Stern-Volmer (S-V) plot shows positive deviation which suggests that quenching is not only due to collision, it may be due to static also. Using Sphere of action static quenching model we analyzed the data of positive deviation in S-V plots. To support the static effects, we obtained static quenching constant 'V' and radius of sphere of action 'r'. Further, to determine the reactions are diffusion limited, we used "Finite Sink Approximation Model" and obtained different parameters. Similarly mutual diffusion co-efficient 'D1' and distance parameter 'R1' are determined from slope of plot by least square fit method. Here R1>R for both solvents therefore we have calculated 4ΠND1R1. With this we can conclude that quenching is efficient and diffusion limited, and Finite Sink Approximation is valid.