Phenylalanine-based polyarylacetylenes as enantiomer-differentiating alignment media.

Lyotropic liquid crystalline phases of a phenylalanine-based polyacetylene are introduced as new enantiodifferentiating alignment media. Based on the unusual temperature dependence of the quadrupolar splitting of the (2)H-signal of the solvent (CDCl(3)), three distinct states of the phase with different orientational properties can be identified. This offers the opportunity to measure multiple alignment data sets without changing the sample. Unexpectedly, the largest difference in the orientation of the enantiomers of isopinocampheol was found in the high temperature domain of the phase. This is even more astonishing because the helical structure of the polymer backbone seems to break down at temperatures above approximately 10 °C, leaving the stereogenic centers of the amino acid moieties in the repeating units as the only reason for the enantiodifferentiation.