Hydrolytic rate constants of p-nitrophenyl esters of w-substituted straight chain acids with various chain lengths [4-O2NC6H4O2C(CH2)n-1R (R = H, OH, SH, Br, SMe; n = 11, 13, 17)] were measured in f = 0.40, 0.45, 0.50, 0.55 Me2SO-H2O mixtures These data demonstrate that for the long-chain substrates 13-SH and 17-SH, hydrophobic-lipophilic forces can bring about 14-membered ring and 18-membered ring neighboring group participations in aggregating solvents. Twelve-membered ring participation has not been observed for 11-SH, indicating that tendencies towards self-coiling and aggregating parallel each other.

Key words: REACTION KINETICS, HYDROLYSIS, NITROBENZENE P, CARBOXYLIC ACID ESTER, BENZENECARBOXYLIC ACID P, C14 COMPOUNDS, REACTION RATE CONSTANT, ENZYMATIC, C18 COMPOUNDS, LONG CHAIN COMPOUND