CSPs Derived from Polymers

In 1974 Blaschke and coworkers introduced new polymer-type CSP materials prepared by suspension polymerization of methacrylamides derived from chiral amines and amino acid esters [187-189]. These CSPs were initially produced in the form of self-supporting beads. However, difficulties arising from extreme polymer swelling and poor mechanical strength prompted later the development of si-hca-supported composite materials with more favorable chromatographic performance characteristics [190]. These improved versions of the CSPs have been com-... 

The important role of the hehcal structure of the polyphenylacetylene derivatives has also been confirmed for 9 (shown in Fig. 3), which has an amide linkage at the 4-position. This L-leucine-based CSP coated on silica gel could resolve all of the racemates 22-29 (Table 2) when the polymer was coated rai silica gel from a methanol-chloroform (3 7) solution [23]. However, the CSP coated from... 

According to their chemical structures, CSPs can be divided into three different groups. A multitude of chiral stationary phases is derived from (modified) natural or synthetic polymers, e.g., the polysaccharides, proteins or polyacrylamides. A second type of selectors is based on large chiral ring systems, such as cyclo-dextrins, macTocycKc antibiotics, and crown ethers. The last group comprises moleailes of small and medium size, such as amino acids and their derivatives, alkaloids, and fuUy synthetic selectors. 

FIGURE 14 Structure of polyamide-based CSP (.s-triazi ne derivative of L-valine isopropyl ester) (condensation polymer). (From Ref. 37.)... 

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