Separation of Positional Isomers on A, C- and A,D-Bridged Calix[6]arene as Stationary Phases in Capillary GC

Abstract

A,C‐Bridged (ACCX) and A,D‐bridged isopropyldimethylsilylcalix[6]arene (ADCX) dissolved in OV‐1701 were used as stationary phases in isothermal capillary gas chromatographic separation of some positional isomers. Retention factors and separation factors for the isomers were measured. The isomers investigated are well resolved on the two phases. Retention of all the solutes investigated is longer on ACCX than on ADCX. The longer retention on A,C‐bridged calix[6]arene is probably due to extra inductive interactions of the solute molecule with the carbonyl moieties in the phase. Separation factors for closely eluting isomer pairs are similar on the two phases. This seems to indicate that the carbonyl moieties do not play an appreciable role in discriminating the isomer molecules on entering the cavity of the calixarene if the solute is retained by the inclusion process.

Preparation and characterization of p-tert-butylcalix[8]arene bonded capillaries for open-tubular capillary electrochromatography

“…They can act as receptor molecules of widely varying size for metal cations and organic molecules [1] and after being shown by Gutsche and Mathukrishnan [2] to mimic the action of enzymes, calixarenes have generated a great deal of scientific interest for three decades. Their cup-shaped architecture formed by ordered, oriented and substituted benzene rings enables calixarenes to include small guest molecules of appropriate size and configuration and this attribute has resulted in widely varying applications in ion-selective membranes and electrodes [3][4][5][6] and chromatography [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24].…”