Investigation on two novel substituted β-cyclodextrins used as GC stationary

The chromatographic behaviors of two dipentyl cyclodextrin derivative stationary phases are presented. Two new β-cyclodextrin derivatives, heptakis-[2,6-di-O-pentyl-3-O-(4-nitrobenzyl)]-CD and heptakis-[2,6-di-O-pentyl-3-O-(5-hexenyl)]-β-CD, were synthesized and coated on fused-silica capillary columns. The chromatographic behaviors of the columns were characterized. It is found that the size, polarity, and aromatic property of the substituted group at the 3-position of heptakis-(2,6-di-O-pentyl)-β-cyclodextrins greatly influence their chromatographic properties and separation ability. The introduction of aromatic group or a group containing a double-bond may bring π-π interactions between the host and guest molecules, and therefore it increases the separation ability of the β-CDs for substituted benzene isomers. The results show that the new substituted β-CD compounds are very suitable for being used as gas chromatographic stationary phases.