Single‐atom exchange series are introduced to extract the individual contributions of halogen bonds and anion–π interactions to the transport of anions across lipid bilayer membranes (see picture). ...Known cation binding sites are used for counterion activation of the neutral calix4arene transporters. The experimental evidence for anion transport with halogen bonds is unprecedented.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Catalysis with Anion-π Interactions Zhao, Yingjie; Domoto, Yuya; Orentas, Edvinas ...
Angewandte Chemie (International ed.),
September 16, 2013, Volume:
52, Issue:
38
Journal Article
Peer reviewed
Open access
The conclusion is inevitable: Increasing stabilization of an anionic transition state with increasing π‐acidity of the catalyst is observed; thus, anion–π interactions can contribute to catalysis.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Lessons from nature call for supramolecular n/p-heterojunctions with oriented multicolored antiparallel redox gradients (OMARG-SHJs) as “ideal” photosystems. Their design combines advantages of ...bilayer and bulk n/p-heterojunction (BHJ) solar cells for the directional separation of photogenerated charges before recombination can occur. Although conceptually attractive, OMARG-SHJs have remained beyond reach because of unresolved challenges in synthetic organic and supramolecular chemistry. Here we report the first OMARG-SHJs with two-component redox gradients in both the electron- and hole-transporting pathways. They were obtained by zipper assembly of stacks of red naphthalenediimide (NDI) electron donors along strings of oligophenylethynyl hole acceptors on top of yellow NDI electron acceptors along p-oligophenyl hole donors. The presence of both gradients is shown to be essential for achieving photoinduced charge separation over very long distances.
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IJS, KILJ, NUK, PNG, UL, UM
In biology and chemistry, the transport of anions across lipid bilayer membranes is usually achieved by sophisticated supramolecular architectures. Significant size reduction of transporters is ...hampered by the intrinsically hydrophilic nature of typical anion-binding functionalities, hydrogen-bond donors or cations. To maximize the atom efficiency of anion transport, the hydrophobic nature, directionality, and strength of halogen bonds seem promising. Unlike the ubiquitous, structurally similar hydrogen bonds, halogen bonds have not been explored for anion transport. Here we report that transport across lipid bilayers can be achieved with small perfluorinated molecules that are equipped with strong halogen-bond donors. Transport is observed with trifluoroiodomethane (boiling point=-22 °C); that is, it acts as a 'single-carbon' transporter. Contrary to the destructive action of small-molecule detergents, transport with halogen bonds is leakage-free, cooperative, non-ohmic and highly selective, with anion/cation permeability ratios <37.
Attractive in theory and confirmed to exist, anion-pi interactions have never really been seen at work. To catch them in action, we prepared a collection of monomeric, cyclic and rod-shaped ...naphthalenediimide transporters. Their ability to exert anion-pi interactions was demonstrated by electrospray tandem mass spectrometry in combination with theoretical calculations. To relate this structural evidence to transport activity in bilayer membranes, affinity and selectivity sequences were recorded. pi-acidification and active-site decrowding increased binding, transport and chloride > bromide > iodide selectivity, and supramolecular organization inverted acetate > nitrate to nitrate > acetate selectivity. We conclude that anion-pi interactions on monomeric surfaces are ideal for chloride recognition, whereas their supramolecular enhancement by pi,pi-interactions appears perfect to target nitrate. Chloride transporters are relevant to treat channelopathies, and nitrate sensors to monitor cellular signaling and cardiovascular diseases. A big impact on organocatalysis can be expected from the stabilization of anionic transition states on chiral pi-acidic surfaces.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Facile access to complex systems is crucial to generate the functional materials of the future. Herein, we report self-organizing surface-initiated polymerization (SOSIP) as a user-friendly method to ...create ordered as well as oriented functional systems on transparent oxide surfaces. In SOSIP, self-organization of monomers and ring-opening disulfide exchange polymerization are combined to ensure the controlled growth of the polymer from the surface. This approach provides rapid access to thick films with smooth, reactivatable surfaces and long-range order with few defects and high precision, including panchromatic photosystems with oriented four-component redox gradients. The activity of SOSIP architectures is clearly better than that of disordered controls.
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Deep blue diving: π Acidities up to a new record of −4.74 eV are made possible with simple sulfur redox chemistry (see scheme). This attractive method is able to generate exceptional electron ...affinities and anion transport efficiencies for applications in optoelectronic devices, medicinal chemistry, and anion–π catalysis.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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