title: Folding-Generated Molecular Tubes Containing One-Dimensional Water Chains.
abstract: 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 π-stacking between two repeating units. Upon helical folding, (1)H NMR signals of aromatic protons were significantly shifted upfield by Δδ = 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.
authors.affiliation: Department of Chemistry, Yonsei University , Seoul 120-749, Korea.
authors.forename: Hae-Geun
authors.initials: HG
authors.lastname: Jeon
authors.affiliation: Department of Chemistry, Yonsei University , Seoul 120-749, Korea.
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Jung
authors.affiliation: Department of Chemistry, Yonsei University , Seoul 120-749, Korea.
authors.forename: Philjae
authors.initials: P
authors.lastname: Kang
authors.affiliation: Department of Chemistry, Yonsei University , Seoul 120-749, Korea.
authors.forename: Moon-Gun
authors.initials: MG
authors.lastname: Choi
authors.affiliation: Department of Chemistry, Yonsei University , Seoul 120-749, Korea.
authors.forename: Kyu-Sung
authors.initials: KS
authors.lastname: Jeong