| Popis: |
The syntheses of a range of quaternary diammonium and some monoammonium salts derived from 1,4-diazabicyclo[2.2.2]octane with N-alkyl arms or N-alkyl arms terminated by a functional group are reported. In aqueous solution they are susceptible to only very slow Hofmann elimination, and the kinetics were investigated for the 1-(2′-ammonioethyl)-4-dodecyl-1,4-diazoniabicyclo[2.2.2]octane ion, which undergoes a base-induced elimination ( kOH 6.9×10-4 dm3 mol-1 s-1 at 55°C) consistent with an ElcB mechanism. In aqueous solution, the diammonium cations are not oxidized but undergo irreversible electrochemical reduction below -1.2 V v . Ag/ AgCl , with the reduction potential apparently influenced by the electron-withdrawing or -donating nature of substituent arms. |
