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-V C H VERLAG GMBH, POSTFACH 101161, 69451 WEINHEIM, GERMANY

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 probe is used to gain insights into theproperties of the benzene/benzyl-n-hexadecyldimethylammoniumchloride (BHDC)/water reverse micelles (RMs) interfaces.The techniques employed were absorption and emissionspectroscopy in addition to the steady-state and, time-resolvedfluorescence emission.For BHDC RMs without water addition, AOBH-DEHP can beused to determine the critical micellar concentration, CMC.Upon addition of water, we detect, at concentrations of BHDClower < 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 thisprocess is reverted because water molecules at the interfaceinteract with the cationic polar head of BHDC through theoxygen non-bonding electron pair enhancing their hydrogenbond ability and acidity, hence it can easily transfer a proton toAOB species to form AOBH+.