Kinetics of partly diffusion controlled reactions. I. Transient and apparent transient effect in fluorescence quenching

Role of solvent polarity on the fluorescence quenching of newly synthesized 7,8-benzo-4-azidomethyl coumarin by aniline in benzene–acetonitrile mixtures

“…encounter distance R is determined. From Table 1, we see that the values of kinetic distance 'r' are greater than the encounter distance R. Therefore, according to Andre et al [26] and Zeng and Durocher [27], the static effect takes place irrespective of ground state complex formation provided the reactions are limited by diffusion indicating the sphere of action model holds well. Further, it may also be noted that a positive deviation in S-V plot is expected when both static and dynamic quenching occur simultaneously [4].…”

Fluorescence quenching of newly synthesized biologically active coumarin derivative by aniline in binary solvent mixtures

“…The value of R ( ¼ R Y +R Q ) referred to as encounter distance is compared with the values of r to check whether the reaction is due to sphere of action model. According to Andre et al [35] and Zeng et al [36], if the distance between the quencher molecule and excited molecule lies between the encounter distance R and kinetic distance r, the static effect predominates especially in the case of steady-state experiments irrespective of ground-state complex formations provided the reactions are limited by diffusion. From Table 2, we see that the values of r are greater than the values of encounter distance R in all the BZ-AN solvents mixtures indicating that the sphere of action model holds good in our case also [27].…”

Quenching mechanisms of 5BAMC by aniline in different solvents using Stern–Volmer plots

“…The study has been mainly to understand the nature of bimolecular reactions taking place both under steadystate and transient conditions. This study has not only been of importance in physical sciences but also in chemical, biological and medical sciences [7][8][9][10][11][12][13][14][15][16][17][18][19]. The fluorescence yield in bimolecular liquid systems is hindered due to several mechanisms such as static and dynamic quenching, excimer and exciplex formation, charge transfer processes, etc.…”