Beschreibung:
<p>Dicarboxamide host 2 forms 1:1 complexes with n-octyl pyranosides derived from D-glucose, D-mannose, D-galactose, D-fucose, D-lyxose, and D-arabinose. Association constants (K<sub>a</sub>) in the range of 77-940 M<sup>-1</sup> were measured in chloroform by means of induced circular dichroism and fluorescence spectroscopy. Variations in K<sub>a</sub> values correspond qualitatively to expected differences in hydrogen-bonding abilities of guest hydroxyl groups. Induced circular dichroism effects for complexes of saccharides bearing equatorial 3-OH, 4-OH, and 6-OH groups show that the host chromophore is twisted in a P-helical conformation. A structural model is proposed that is also consistent with the results of previous studies involving complexation of dicarboxylic acid 1 with cationic saccharides in methanol.</p>