Properties of Alkanediyl-1, ω-Bis-Quaternary Ammonium Salts with Two Long-Alkyl Chains

Abstract

Bis-quaternary ammonium salts [Cm-Bis (N-Cn)] possessing two equivalent ammonium groups substituted with one long-alkyl chain (n : 1016) and two methyl groups, and a connecting alkanediyl chain (m : 26), were synthesized from alkyldimethylamine and 1, ω-dibromoalkane. Surface-active properties such as foaming and solubilization capacity were measured and the catalytic activity of bis-quaternary ammonium salts in phase transfer halide exchange reaction was examined.Foam volume increased with increase in concentration of Cm-Bis (N-Cn) until it reached to nearly that of critical micelle concentration (cmc), in the region of which showed maximum foam volume. Foaming capacity and foam stability of Cm-Bis (N-Cn) increased with alkyl chain n (n : 10→12→14) and then decreased remarkably at n : 16. Both parameters decreased monotonously with increase in connecting chain m. The solubilizing power of Cm-Bis (N-Cn) increased with n and m (m : 2→6). Catalytic activity in a phase transfer reaction increased with n (n : 10→12→14), becoming maximum at 14, followed by decrease at 16. It increased with m (m : 2→3→4) but subsequently decreased with further increase in m.