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

CROSIO, MATÍAS A.; SILBER, JUANA J.; MOYANO, FERNANDO; CORREA, N. MARIANO; FALCONE, R. DARÍO

ChemistrySelect

Wiley-VCH

Año: 2017 vol. 2 p. 2880 - 2887

This work presents the use of the molecular probe: 3,6-bis (dimethylamino) acridinium bis-(2-ethylhexyl)phosphate salt, AOBH-DEHP.This probeisused 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 fluorescenceemission. For BHDC RMs withoutwater addition, AOBH-DEHP can be used to determine the criticalmicellar concentration, CMC.Upon addition of water,wedetect,atconcentrations of BHDC lower < 1x10-2 M, aprotontransfer processfrom 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 oxygennon-bondingelectron pair enhancingtheir hydrogen bond ability and acidity,hence it can easily transfer aproton to AOB speciestoform AOBH+.