Binding of o-nitroaniline to nonaqueous AOT reverse micelles

Abstract

The binding of o-nitroaniline (o-NA) to the micellar interface of n-heptane/1,4-bis(2-ethylhexyl) sulfosuccinate (AOT)/nonaqueous polar solvent reverse micelles was determined by UV-visible spectroscopy. As polar solvents: ethylene glycol (EG), formamide (FA), glycerol (GY), dimethylacetamide (DMA) and dimethylformamide (DMF) were used. The binding constant, Kb, obtained follow the order: DMF ∼ DMA > FA ∼ WS = 0 > EG > water > GY. It is demonstrated that the o-NA - AOT hydrogen bond interaction is with the AOT sulfonate moiety. Thus, the more accessible that this group is for hydrogen bond interaction the larger is the Kb value.