Combined static and dynamic quenching in micellar systems—closed-form integrated rate laws verified using a versatile probe. Issue 13 (15th March 2017)

• Record Type: Journal Article
• Authors: Kohlmann, Tim; Naumann, Robert; Kerzig, Christoph; Goez, Martin
• Is Part Of: Physical chemistry chemical physics. Volume 19:Issue 13(2017)
• Page Start: 8735
• Page End: 8741
• Publication Date: 2017-03-15
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c6cp08491e
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : One probe to rule them all: an extremely long-lived radical cationM ˙ + generated by green-light photoionization allowed new theories of combined static and dynamic intra- and intermicellar quenching to be tested. Abstract : We demonstrate that the 3-aminoperylene radical cation is a near-ideal probe for investigating kinetic and transport processes in SDS micellar systems. Its isolated generation by two-photon ionization at a wavelength where most quenchers are transparent (532 nm) is free from side reactions; no exit from the micelles is detectable on a millisecond timescale; and its unquenched lifetime is as long as 350 ms, thus allowing the study of quenching processes over a time frame spanning at least 7 orders of magnitude. The lipophilic antioxidant ascorbyl palmitate reconverts it to its parent compound through the interplay of static and fast dynamic intramicellar quenching as well as through subsequent slow intermicellar migration. Using this radical-cation probe, we have successfully validated closed-form expressions which we derived for the probe decay in all these situations. From these functions, we also obtained an exact and closed-form analytical result for Stern–Volmer experiments with combined static and dynamic intramicellar quenching.