title: Bifunctional calix[4]arene sensor for Pb(II) and Cr2O7(2-) ions.
abstract: A readily available chromionophore 5,11,17,23-tetra-tert-butyl-25,27-bis(hydrazidecarbonylmethoxy)-26,28-dihydroxycalix[4]arene (HCC4) was employed as a chromogenic sensing probe selective for Pb(II) and Cr2O7(2-) ions among a series of various ions such as Li(I), Na(I), K(I), Rb(I), Ba(II), Sr(II), Al(III), Cd(II), Co(II), Cu(II), Hg(II), Ni(II), Pb(II) and Zn(II) as well as Cr2O7(2-), CH3CO2(-), Br(-), Cl(-), F(-), I(-), ClO4(-) and NO3(-) that have been examined by UV-visible and fluorescence spectroscopic techniques. The HCC4 in DCM-MeCN system forms 2:1 (ligand-metal) complex with Pb(II). It also shows 2:1 stoichiometry with Cr2O7(2-). The complexation phenomenon has been confirmed by FTIR spectroscopy that favors the selective nature of HCC4 with Pb(II) and Cr2O7(2-). Thermal gravimetric analysis (TGA) also supports its utility in drastic conditions.
authors: National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Pakistan.
authors: Mansoor Ahmed
authors: MA
authors: Qazi
authors: Ummühan
authors: U
authors: Ocak
authors: Miraç
authors: M
authors: Ocak
authors: Shahabuddin
authors: S
authors: Memon
authors: Imam Bakhsh
authors: IB
authors: Solangi
mesh_terms: D047250:Calixarenes / Q000737:chemistry*; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation*; D002840:Chromates / Q000032:analysis* / Q000737:chemistry* / Q000302:isolation & purification; D003116:Color; D006834:Hydrazines / Q000737:chemistry*; D007854:Lead / Q000032:analysis* / Q000737:chemistry* / Q000302:isolation & purification; D059625:Liquid-Liquid Extraction; D010636:Phenols / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: C584938:5,11,17,23-tetra-tert-butyl-25,27-bis(hydrazidecarbonylmethoxy)-26,28-dihydroxycalix(4)arene; D002840:Chromates; D006834:Hydrazines; D010636:Phenols; D012997:Solvents; C121325:calix(4)arene; D047250:Calixarenes; D007854:Lead