Dual responsive chemosensors for anion and cation: Synthesis and studies of selective chemosensor for F― and Cu(II) ions

摘要: Abstract New colorimetric chemosensors, 1-[2-{(4-nitrobenzylidene)amino}phenyl]-3-phenylthiourea ( 1 ), 1-[2-{(2-hydroxy-5-nitrobenzylidene)amino}phenyl]-3-phenyl thiourea 2 ) have been synthesized and characterized by spectroscopic techniques XRD. The molecular structure of receptor was determined X-ray crystallography it has the triclinic space group P with cell parameters a  = 7.2705 A (6), b  = 11.0178 A (9) c  = 12.0137 A Z  = 2. Anion binding studies carried out using H NMR UV–visible spectrophotometric titrations revealed that these receptors exhibit selective recognition towards F − over other halide anions. selectivity for among halides is attributed mainly to hydrogen-bond interaction . Receptors (5 × 10 −5  M) show color change from colorless brown yellow respectively in presence tetrabutylammonium fluoride (TBAF, 5 × 10 −3  M). Moreover, -induced changes remain same even large excess Cl , Br I Chromogenic undergo distinct violet or bluish green on gradual addition Cu(II) can be used as probes visual analysis transition metal ions such Mn 2+ Co Ni Zn constant found higher than ion this may due OH which offers extra site.