HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC ENANTIOMERIC RESOLUTION IN THE 10-VERTEX CARBORANE SERIES - COMPARISON OF ACETYL-CYCLODEXTRIN-BONDED AND NATIVE BETA-CYCLODEXTRIN-BONDED CHIRAL STATIONARY PHASES

The HPLC resolution on native and acetyl P-cyclodextrin columns is rep orted for thirteen enantiomeric pairs of racemates, members of two ser ies of positional isomers in the ten-vertex carborane family, the exo- 9-L-arachno-5,6-C2B8H12 (L = NH3, primary or secondary amino group) or exo-6-L-arachno-5,10-C2B8H12 (L = secondary or tertiary amino group). The study of influence of the structural factors on retention, select ivity and resolution of individual compounds is described on both chir al stationary phases (CSPs). The deep differences in enantio-selectivi ties has been observed for native and acetyl beta-cyclodextrin CSPs. C ircular dichroism (CD) spectra of exo-9-t-BuNH2-arachno-5,6-C2B8H12 an d exo-6-Et3N-arachno-5,10-C2B8H12, members of each series are presente d. The CD results indicate the different enantiodiscrimination mechani sm on the two CSPs under study. (C) 1998 Elsevier Science B.V.