Poly(L-lactic acid) is a linear aliphatic thermoplastic polyester that can be produced from renewable resources. A poly(L-lactic acid)-modified silica stationary phase was newly prepared by amide bond reaction between amino groups on aminopropyl silica and carboxylic acid groups at the end of the poly(L-lactic acid) chain. The poly(L-lactic acid)-silica column was characterized in reversed-phas...

A series of NNO ketoimines bearing trifluoromethyl substituents were synthesized from the Schiff base condensation of 1,3-diketones (1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione, 4,4,4-trifluoro-1-phenyl-1,3-butanedione, and 1,1,1-trifluoro-2,4-pentanedione, 1,1,1,5,5,5-hexafluoroacetylacetone) and 8-aminoquinoline or 8-amino-2-methylquinoline and isolated in 40-70% yield. The ketoimines were c...

A novel class of stereocomplexes is described by the interaction of helically complementary poly(phenylacetylene)s (PPAs) carrying an α-methoxy-α-trifluoromethylphenylacetamide pendant group. The formation of the stereocomplex requires the presence of cis amide bonds on the external crest of the polymer to provide efficient cooperative supramolecular hydrogen bonding between matching enantiomer...

Appropriate values for the orientation of the amide transition dipoles are essential to the growing use of isotopically edited vibrational spectroscopy generally in structural biology and to infrared dichroism measurements on membrane-associated -helices, in particular. The orientations of the transition moments for the amide vibrations of an -helix have been determined from the ratio of intens...

BACKGROUND The introduction of pendent bulky groups along the polymer backbone results in a less ordered polymer matrix and increases the solubility characteristics without affecting thermal properties. The inclusion of chromogenic chemical moieties in the chains can give rise to the luminescent converter material which permits the preparation of materials with potential applications. Aromatic ...