title: Photocontrol of Anion Binding Affinity to a Bis-urea Receptor Derived from Stiff-Stilbene.
abstract: Toward the development of photoresponsive anion receptors, a stiff-stilbene photoswitch has been equipped with two urea anion-binding motifs. Photoinduced E/Z isomerization has been studied in detail by UV-vis and NMR spectroscopy. Titration experiments (1H NMR) reveal strong binding of acetate and phosphate to the (Z)-isomer, in which the urea groups are closely together. Isomerization to the (E)-form separates the urea motifs, resulting in much weaker binding. Additionally, geometry optimizations by density functional theory (DFT) illustrate that oxo-anion binding to the (Z)-form involves four hydrogen bonds.
authors.affiliation: Stratingh Institute for Chemistry, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.
authors.forename: Sander J
authors.identifier: 0000-0001-9192-3393
authors.initials: SJ
authors.lastname: Wezenberg
authors.affiliation: Stratingh Institute for Chemistry, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.
authors.forename: Ben L
authors.initials: BL
authors.lastname: Feringa