Motivated by a recent identification of two homologous series of branched
butanoates and pentanoates in S. pecten-veneris essential oil, with an
apparently regular change of their retention index (RI) values, we decided to
examine the generality of such structure-chromatographic property
relationship. Based on the experimentally obtained retention data (RI values
of in total 20 compounds) of hexyl, decyl, tridecyl, tetradecyl, pentadecyl,
hexadecyl, heptadecyl, octadecyl, heneicosyl and tricosyl isobutanoates and
3-methylbutanoates and selected 2-methylbutanoates, a model was built up that
correlates the total number of carbon atoms, Wiener (WI), Balaban (BI) and
molecular topological (MTI) indices of the mentioned esters and their RI data
(RI = 240.5 + 91.2 x C + 2.94 x WI + 4.6 x 10-5 x BI - 0.381 x MTI). The
obtained equation represents a new and simple tool for the prediction of gas
chromatographic (retention indices) data for esters of straight long-chain
fatty alcohols and branched short aliphatic acids.