Synthesis of a cationic polyelectrolyte by successive quaternization of 1,4-bis(2-diethylaminoethyl)benzene

1,4-Bis(2-diethylaminoethyl)benzene ( 4 ), synthesized from 1,4-divinylbenzene ( 1 ) and diethylamine ( 2 ) with lithium diethylamide as catalyst, was successively quaternized with 1,4-dibromobutane ( 5 ) to prepare a cationic polyelectrolyte 6 of the ionene type. Apparent molecular weights of the ionene samples were estimated by the sedimentation equilibrium method, and the result is discussed in connection with the true molecular weight. The rate constants for quaternization of first and second nitrogen atom of 4 (k₁ and k₂) were determined by the use of ¹³C NMR. It was found that the ratio of the rate constants, (k₂/(k₁/2)), markedly decreased in the 4/5 system, though it remained unity in the 4 ethyl bromide system.