Adsorption isotherms and retention behavior of 1,1'-bis(2-naphthol) on CHIRIS AD1 and CHIRIS AD2 columns.

The separation of the atropoisomers of 1,1'-bis(2-naphthol) was studied on CHIRIS AD1 and CHIRIS AD2, two Pirkle-type chiral stationary phases. Satisfactory selectivity was found only on CHIRIS AD2. The ternary mobile phases comprised hexane, dichloromethane and methanol.

Novel chiral stationary phases comprising 2,4-(or 2,6)-diamino-5,6-(or 2,5)-dichlorobenzene-1,3-dicarbonitrile and 1-acyl (1R,2R)-diaminocyclohexane.

Novel chiral selectors 3-5 were prepared by regioselective nucleophilic substitution of 2,4,5,6-tetrachlorobenzene-1,3-dicarbonitrile (TCBDC, 1) at C(4) by (1R,2R)-trans-diaminocyclohexane, followed by acylation of the intermediary 2 with carboxylic acids containing pi-acid or pi-basic unit. On substitution of the second chlorine atom by the spacer 3-aminopropyltriethoxysilane (APTES), a 1:1 mixture of regioisomers of N-(([3, 6-dichloro-2,4-dicyano-5-(4,4,4-triethoxy-4-silabutyl)-amino]phenyl)amino) cyclo-hexylcarboxamides and N-(5,6-dichloro-2,4-dicyano-3-(4,4,4-triethoxy-4-silabutyl)-amino]pheny) amino)cyclohexylcarboxamides (6/7, 8/9, 10/11) was obtained. Their covalent binding to Nucleosil 100-5 provided three new chiral stationary phases (CSP-1-CSP-3).