Solvophobically-driven oligo(ethylene glycol) helical foldamers. Synthesis, characterization, and complexation with ethane-1,2-diaminium.

Oligo(ethylene glycols) 1a-h, which are incorporated with one to eight 2,3-naphthylene units, respectively, have been synthesized and characterized. The conformational changes of the new oligomers have been investigated in chloroform-acetonitrile binary solvents by the UV-vis, (1)H NMR, and fluorescent spectroscopy. It has been revealed that the naphthalene units in hexamer 1f, heptamer 1g, and octamer 1h are driven by solvophobic interaction to stack in polar solvents.

Zipper-featured delta-peptide foldamers driven by donor--acceptor interaction. Design, synthesis, and characterization.

Donor-acceptor interaction between electron-rich 1,5-dioxynaphthalene (DAN) and electron-deficient pyromellitic diimide (PDI) has been utilized to induce the formation of a new kind of zipper-featured delta-peptide foldamers. Seven l-ornithine-based delta-peptides 1a-g, in which one to three DNA and PDI units are incorporated to the two ends of the peptide backbones, respectively, have been designed and prepared by the standard liquid-phase synthetic method. (1)H NMR, UV-vis, and fluorescent quenching studies reveal that all the delta-peptides adopt folding conformations in nonpolar chloroform and polar DMF as a result of intramolecular donor-acceptor interaction between the DAN and PDI units.

First zipper-featured molecular duplexes driven by cooperative donor-acceptor interaction.

[structure: see text] The first class of zipper-shaped artificial duplexes, which are driven by multiple donor-acceptor interactions between electron-rich 1,5-dioxynaphthalene or 1,4-dioxybenzene and electron-deficient pyromellitic dimide units, have been studied in organic media by (1)H NMR, UV-vis, and vapor pressure osmometry. (1)H NMR binding investigations reveal substantial cooperativity of the donor-acceptor interaction in the duplexes.