SHAPE AND AGGREGATING TENDENCY - THE AGGREGATING BEHAVIOR OF 8 ESTERSOF 8-CARBON CARBOXYLIC-ACIDS

The aggregating tendencies of eight p-nitrophenyl esters of eight-carb on carboxylic acids (1-8) and two O-octyl phosphonates (10, 11) have b een evaluated by measuring their critical aggregate concentrations (CA gC's). Results show that (1) branching reduces aggregating tendency an d (2) flexibility of the hydrocarbon chain favors aggregation. The beh avior of a ''spheroidal'' molecule 8 shows that shape is undoubtedly a n important factor that affects the aggregating tendency. This conclus ion is unmistakably confirmed by the CAgC of an ester of the seven-car bon acid 9.