title: Design, synthesis and ¹H NMR study of C3v-symmetric anion receptors with urethane-NH as recognition group.
abstract: C3v-Symmetric anion receptors 3 and 4 with urethane groups were synthesized by using trindane triol as tripodal molecular framework. In (1)H NMR titration study, the receptors showed noticeable downfield shift/disappearance of the urethane-NH peak in presence of H2PO4(-) and F(-) due to the host-guest complexation occurred through multiple hydrogen bonding and/or the deprotonation of urethane-NH groups. Other tested anions such as Cl(-), Br(-), HSO4(-), and NO3(-) showed either no or negligible chemical shift of the urethane groups. The deprotonation event in 4 allowed selective detection of F(-) by perceptible color change from colorless to yellowish-red with the appearance of a new charge transfer absorption band at 450 nm.
authors: Department of Applied Chemistry, Kyungpook National University, Daegu 701-702, South Korea.
authors: Jin-Oh
authors: JO
authors: Park
authors: Department of Applied Chemistry, Kyungpook National University, Daegu 701-702, South Korea; Department of Applied Chemistry, SV National University of Technology, Surat 395007, Gujrat, India.
authors: Suban K
authors: SK
authors: Sahoo
authors: Department of Applied Chemistry, Kyungpook National University, Daegu 701-702, South Korea. Electronic address: choihj@knu.ac.kr.
authors: Heung-Jin
authors: HJ
authors: Choi
keywords: (1)H NMR; Anion recognition; C(3v) symmetry; Tripodal receptors; Urethane-NH