Chromatographic Separations of Oligovinylpyridines. II. HPLC Separations of Radically and Anionically Oligomerized 2- and 4-Vinylpyridines

Abstract

HPLC-separations of oligomers obtained by radical and anionic oligomerization of 2- and 4-vinylpyridine by means of gradient elution are reported. The eluent systems used were pentane/methanol and nitrous oxide/methanol. Elution is shown to occur more rapidly with 2-vinylpyridine oligomers. Using nitrous oxide/methanol, separation with respect to degree of oligomerization was enhanced compared to pentane/methanol. Differences in the elution behavior of 2- and 4-vinylpyridine oligomers are ascribed to differences in interactions of the respective oligomer molecules with the stationary and the mobile phase, caused by the different position of the nitrogen atom in these two oligomer types.