THE INFLUENCE OF SOLUTE STRUCTURE, TEMPERATURE, AND ELUENT COMPOSITION ON THE CHIRAL SEPARATION OF 21 AMINOTETRALINS ON A CELLULOSE TRIS-3,5-DIMETHYLCARBAMATE STATIONARY PHASE IN HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

In the present study 21 different chiral aminotetralins were used to investigate the mechanism behind their enantiomeric resolution (R(s)) on a commercially available high-performance liquid chromatography (HPLC) cellulose tris-3,5-dimethylcarbamate stationary phase. The differences in the chemical structures of the aminotetralins used were never directly located on the chiral carbon. Their chromatographic behavior was studied for two eluent compositions at six different temperatures. Hydrogen bonding and pi-pi interactions are two possible solute-chiral stationary phase (CSP) interactions. Differences between the enantiomers in their spatial arrangement of positions involved in solute-CSP interactions were the major forces behind enantiomeric separation. Lowering the temperature increased the R(s) for the aminotetralins having pi-electrons not directly bonded to that part of the molecule where the hydrogen bonding with the CSP is located. Primary amines and secondary amines, with a sufficiently short N-alkyl substituent, showed a decrease of R(s) with lower temperatures, all other aminotetralins yielding an increase of R(s) with lower temperatures.