Synthesis and evaluation of a copolymeric chiral stationary phase

A copolymer based on a broadly applicable chiral selector has been synthesized by hydrosilylation of an enantiopure diallyl derivative of 4-(3,5-dinitrobenzamido)-3-propyl-1,2,3,4-tetrahydrophenanthrene with a difunctional oligomethylhydrosiloxane. The linear copolymer has alternating selector-oligomer units, providing a well-defined strand. The spacing between the chiral units is controlled by the length of the oligomethylhydrosiloxane units. This new chiral stationary phase shows improved chromatographic performance relative to its brush-type and sidechain-modified polysiloxane analogs, as evidenced by data obtained by high-performance liquid and supercritical fluid chromatography. The copolymeric CSP affords increased enantioselectivity under cryogenic conditions and loses little chromatographic efficiency at optimized flow-rates under these conditions. (C) 1998 Elsevier Science B.V.