Structure-retention correlations of hydrocarbons in GLC and GSC alkenylbenzenes

For the study of relationships between retention behaviour and molecular structure in GLC and GSC the retention indices of alkenylbenzenes with 2–6 carbon atoms in a straight or branched side chain and of isotopological alkylbenzenes were determined on capillary columns coated with OV-1 and Ucon LB and on a micropacked column filled with graphitized thermal carbon black. From the values obtained index differences corresponding to the increments of the double bond in the side chain were derived. These differences depend significantly on the structure of the side chain and of the position of the double bond. In the case of 1-phenyl-1-alkenes the double bond close to the aromatic ring gives rise to an increase of retention values, especially for the trans-isomers, causing remarkable retention differences between the cis and transisomers. The alkenylbenzenes which exhibit a terminal double bond are less strongly retained than the isotopological alkylbenzenes.