SENSITIZED PHOSPHORESCENCE WITH ANCHORED NAPHTHOATE ENERGY DONORS IN REVERSE MICELLES

A series of cetyltrimethylammonium (CTA+) surfactants with naphthoate counterions have been used as donors of triplet-state energy for the acceptor blacetyl in reverse micelles of Aerosol OT (AOT). Microviscosities obtained by using fluorescence polarization measurements have been employed to describe the relative binding of different naphthoate counterions to the interfacial region of the micelle. Since the naphthoate moieties are associated with the CTA+ surfactant, they are anchored to the head groups in reverse micelles of AOT where biacetyl is solubillzed. Therefore, cetyttri-methylammonium naphthoate acts as a more efficient energy donor than the corresponding sodium salt that is not bound as effectively to the micelle interface. Counterion binding and several other parameters that affect the intensity of sensitized phosphorescence have been examined. © 1990, American Chemical Society. All rights reserved.