화학공학소재연구정보센터
Journal of the American Chemical Society, Vol.138, No.1, 92-95, 2016
Folding-Generated Molecular Tubes Containing One-Dimensional Water Chains
A series of indolocarbazole-pyridine (IP) oligomers were prepared that fold into helical conformations, and their folding features in solution and in the solid state were revealed. Helical folding of these IP foldamers is induced by dipolar interactions through the ethynyl bond and pi-stacking between two repeating units. Upon helical folding, H-1 NMR signals of aromatic protons were significantly shifted upfield by Delta delta = 0.5-2.2 ppm. In addition, hypochromic shifts and fluorescence quenching were observed in the absorption and emission spectra. X-ray crystal structures clearly demonstrated that IP foldamers folded to helical structures with cylindrical internal cavities wherein 3 or 5 water molecules were occupied by hydrogen-bonding interactions in a 1-D array, reminiscent of transmembrane water channels, called aquaporins.