6,6'-DINITROBIPHENYL-2,2'-DICARBOXYLIC ACID IONICALLY BONDED TO AMINOPROPYL SILICA - NEW AXIALLY CHIRAL PHASE OF C-2 SYMMETRY FOR HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC SEPARATION OF ENANTIOMERIC AMINO ALCOHOL DERIVATIVES

(R)-(+)-6,6'-Dinitrobiphenyl-2,2'-dicarboxylic acid, ionically bonded to 3-aminopropylsilanized silica (CSP 1), is the first ionically bonde d axially chiral phase of C-2 symmetry. The phase is specifically effi cient for the separation of a wide range of enantiomeric vicinal benza mido alcohols, whether open-chain, cyclic or polycyclic. To assess the steric and polar effects of the 6,6'-substituents, the performance of CSP 1 is compared with that of the analogous (but less effective) pha se CSP 2, based on (S)-(+)- 6,6'-dimethylbiphenyl-2,2'-dicarboxylic ac id. Some conclusions about the relation between the separation effecti vity and the analyte structure, as well as about the factors involved in the chiral recognition process, are given.