NATURE OF THE ALTERNATE CF2CH2 CHAIN - STUDY BASED ON THE MEASUREMENTAND COMPARISON OF THE CAGCS OF AGGREGATORS WITH ALTERNATE CHAINS AND WITH HYDROCARBON CHAINS

The saponification rate constants of p-nitrophenyl esters of carboxyli c acids with the hydrocarbon chain and the alternate CF2CH2 chain, i.e ., H(CH2CH2)((m-1)/2)COOC6H4NO2 (C-m) and Cl(CF2CH2)((m-1)/2)COOC6H4NO 2 (AL-m), in which m stands for the number of chain-carbon atoms and i s equal to 3, 5, 7, 9, 11, and 13, have been measured in the 20:80 (v/ v) (Phi = 0.20) buffered dioxane-H2O binary solvent. Meanwhile, the fl uorescence spectra of 2-(alpha-naphthyl)ethyl esters of carboxylic aci ds with the hydrocarbon chain and the alternate CF2CH2 chain, i.e., H( CH2CH2)((m-1)/2)COOCH2CH2C10H7 (Fl-C-m) and Cl(CF2CH2)((m-1)/2)COOCH2C H2 C10H7 (Fl-AL-m) (m = 3, 5, 7, 9, 11, and 13) have been measured in the Phi = 0.20 dioxane-H2O solvent system. Critical aggregate concentr ation (CAgC) Values derived from the aforesaid kinetic and spectral me asurements revealed that the alternate chain possesses a smaller tende ncy toward aggregation than the hydrocarbon chain does. Therefore, the alternate CF2CH2 chain seems to possess a minute degree of polarity. It has been shown that even neutral organic molecules with a three-car bon chain could show some aggregating tendencies, and our results impl y that simple aggregates are formed by a stepwise process.