Park Jin-Oh, Sahoo Suban K, Choi Heung-Jin
Department of Applied Chemistry, Kyungpook National University, Daegu 701-702, South Korea.
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.
Spectrochim Acta A Mol Biomol Spectrosc. 2016 Jan 15;153:199-205. doi: 10.1016/j.saa.2015.08.015. Epub 2015 Aug 14.
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.