Optically active polyamides consisting of anti head-to-head coumarin dimer and α,ι-alkanediamine. Odd-even discrimination in chiral recognition ability depending on the number of the diamine component and correlation between the ability and crystallizability

Abstract

Optically active polyamides, derived from (-)-anti head-to-head coumarin dimer and , -alkanediamines, possess possible interaction sites for chiral recognition. Their chiral recognition ability was evaluated by using them as chiral stationary phases for high-performance liquid chromatography; they were found to be highly dependent on the methylene number in the diamine components. The polyamides, consisting of a diamine with an even methylene number, showed a sufficient chiral recognition ability, while the polyamides with an odd methylene number did not at all. This odd-even discrimination in chiral recognition was in good agreement with the crystallizability of the polyamides; i.e., only crystallizable polyamides showed a chiral recognition ability. The chiral recognition ability was also closely related to the degree of crystallinity and to the superstructure of the polyamides. The degree of crystallinity of the polyamides coated on the surface of silica gel was significantly influenced by the poor solvent for washing and by the quantity of a residual coating solvent.

Evaluation of two pairs of chiral stationary phases: Effects from the length of the achiral spacers

“…The length of the achiral spacers has previously been shown to influence the enantiodiscriminating ability. 21,22 The structure of the polymer formed seems to be very important for the enantioselectivity of the chiral stationary phases. Comparing DEABA with DEABU and DTMB with DTMU, the chromatographic results indicate that the selectors with the longer spacers form polymers, which have structures less favorable for enantiodiscrimination.…”

Synthesis and Characterization of New Optically Active Poly(amide-imide)s Based on N,N′-(Pyromellitoyl)-bis-L-Amino Acids and 1,3,4-Oxadiazole Moieties

“…Because of the chirality, living organisms usually show different biological responses to one or the other of a pair of enantiomers or optical isomers whether they are drugs, pesticides or wastes. Synthesis and characterization of optically active polymers has been a challenging theme in the field of polymer synthesis in recent years for their important applications of optically active polymers as catalysts for asymmetric synthesis [12,13] and as chiral stationary phases (CSP) for the direct optical resolution of enantiomers [14][15][16][17]. Optically active polymers can be obtained by polymerization of optically active monomers or by stereo-selective polymerization of racemic or prochiral monomers using optically active catalysts.…”

A simple and efficient way to synthesize optically active polyamides by solution polycondensation of di‐O‐methyl‐L‐tartaryl chloride with diamines

“…Polyamides are widely recognized for their excellent thermal, mechanical, and chemical properties 1. Some optically active polyamides can be used as chiral membrane separation materials or chiral stationary phases for high performance liquid chromatography because of the chiral recognition ability 2–6. In recent years, the use of carbohydrate derivatives to prepare polyamides has received much attention, and the interest arises not only from the naturally occurring character of the feedstock but also from the potential that such polymers are used for biodegradable and biocompatible materials in the biomedical field 7–12…”