title: Tetra-(meta-butylcarbamoyl)azobenzene: A Rationally Designed Photoswitch with Binding Affinity for Oxoanions in a Long-Lived Z-State.
abstract: A new photoswitchable anion receptor 1 based on a tetra-meta-substituted azobenzene skeleton has been readily synthesized in two steps. Titration studies (1H NMR) and theoretical predictions (DFT/M06-2X/6-31G(d)/DMSO-SM8) revealed that nonplanar Z-1 is a better host for anions than E-1, which results from the greater ability of four amide NH protons in the Z-state to cooperatively bind oxoanions, in particular tetrahedral H2PO4-and H2AsO4-. Furthermore, the thermal decay of Z-1 (τ1/2= 11 days) is not accelerated by anion binding.
authors.affiliation: Institute of Organic Chemistry, Polish Academy of Sciences , Kasprzaka 44/52, 01-224 Warsaw, Poland.
authors.forename: Kajetan
authors.identifier: 0000-0001-7767-5303
authors.initials: K
authors.lastname: Dąbrowa
authors.affiliation: Institute of Organic Chemistry, Polish Academy of Sciences , Kasprzaka 44/52, 01-224 Warsaw, Poland.
authors.forename: Janusz
authors.identifier: 0000-0002-0351-6614
authors.initials: J
authors.lastname: Jurczak