Design, synthesis and ¹H NMR study of C3v-symmetric anion receptors with urethane-NH as recognition group

Spectrochim Acta A Mol Biomol Spectrosc. 2016 Jan 15:153:199-205. doi: 10.1016/j.saa.2015.08.015. Epub 2015 Aug 14.

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.

Keywords: (1)H NMR; Anion recognition; C(3v) symmetry; Tripodal receptors; Urethane-NH.

Publication types

  • Research Support, Non-U.S. Gov't