The Use of AOBH‐DEHP Molecular Probe to Characterize BHDC Reverse Micelles Interfaces. Insights on the Interfacial Water Structure

Abstract

AbstractThis work presents the use of the molecular probe: 3,6‐bis(dimethylamino) acridinium bis‐(2‐ethylhexyl) phosphate salt, AOBH‐DEHP. This probe is used to gain insights into the properties of the benzene/benzyl‐n‐hexadecyldimethylammonium chloride (BHDC)/water reverse micelles (RMs) interfaces. The techniques employed were absorption and emission spectroscopy in addition to the steady‐state and, time‐resolved fluorescence emission.For BHDC RMs without water addition, AOBH‐DEHP can be used to determine the critical micellar concentration, CMC. Upon addition of water, we detect, at concentrations of BHDC lower < 1x10−2 M, a proton transfer process from the AOBH+ cation to the DEHP− anion producing AOB species. However, for [BHDC] > 10−2 M, when the RMs is completely formed this process is reverted because water molecules at the interface interact with the cationic polar head of BHDC through the oxygen non‐bonding electron pair enhancing their hydrogen bond ability and acidity, hence it can easily transfer a proton to AOB species to form AOBH+.