Interaction of proflavin with tryptophan in reverse micellar microenvironment of AOT: Photoinduced electron transfer probed by magnetic field effect

Photoinduced electron transfer (PET) from a biological amine, tryptophan to a well-known acridine-derivative, proflavin has been investigated employing laser flash photolysis technique in heterogeneous AOT reverse micelles (RMs). In AOT RMs a significant magnetic field effect (MFF) on PET has been observed which authenticates the triplet spin states of the precursors of PET. The measurement of B1⁄2 value gives an indication of the extent of hyperfine interactions present in the system in AOT medium. The cause of discrepancy between calculated and experimental B1⁄2 values is explained. Further, it is observed that MFE decreases with increase in pool size of the RMs which highlights the importance of optimum separation between the corresponding radical ions pairs to maximize MFE.