title: Experimental and theoretical study of urea and thiourea based new colorimetric chemosensor for fluoride and acetate ions.
abstract: Two new anion receptors 1,1-(4-nitro-1,2-phenylene) bis(3-phenylurea) (1) and 1,1-(4-nitro-1,2-phenylene) bis(3-phenylthiourea) (2) have been reported here. The binding and colorimetric sensing properties of receptors 1 and 2 with different anions were investigated by naked-eye, (1)H-NMR and UV-Vis spectroscopy. They showed effective and selective binding with two biologically important anions F(-) and CH3COO(-), in presence of other anions, such as Cl(-), Br(-), I(-), NO2(-), ClO4(-), HSO4(-), H2PO4(-), N3(-), CN(-) in acetonitrile. The relative binding mode of fluoride and acetate anions towards receptors 1 and 2 were studied using density functional theory (DFT), in gas phase and in acetonitrile solvent. Computational studies revealed that receptor 1 formed complexes by two intermolecular hydrogen bonds while receptor 2 by three intermolecular hydrogen bonds. In addition, time dependent DFT (TD-DFT) calculations qualitatively match the experimental UV-Vis spectra.
authors.affiliation: Department of Chemistry, Dibrugarh University, Dibrugarh 786004, Assam, India.
authors.forename: Eramoni
authors.initials: E
authors.lastname: Saikia
authors.affiliation: Department of Chemistry, Dibrugarh University, Dibrugarh 786004, Assam, India.
authors.forename: Manash Protim
authors.initials: MP
authors.lastname: Borpuzari
authors.affiliation: Department of Chemistry, Dibrugarh University, Dibrugarh 786004, Assam, India. Electronic address: bolinchetia@dibru.ac.in.
authors.forename: Bolin
authors.initials: B
authors.lastname: Chetia
authors.affiliation: Department of Chemistry, Dibrugarh University, Dibrugarh 786004, Assam, India. Electronic address: rahul.kar.dib@gmail.com.
authors.forename: Rahul
authors.initials: R
authors.lastname: Kar
mesh_terms: D000085:Acetates / Q000032:analysis*; D003124:Colorimetry / Q000379:methods; D005459:Fluorides / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013890:Thiourea / Q000031:analogs & derivatives*; D014508:Urea / Q000031:analogs & derivatives*
chemical_list: D000085:Acetates; D014508:Urea; D013890:Thiourea; D005459:Fluorides
keywords: Anion receptor; Colorimetric sensing; DFT; ICT; Naked-eye detection