Sharif Digital Repository

Fluorescence spectroscopy of a series of N2O2-donor naphthodiaza-crown macrocyclic ligands, L1-L4 , in ethanol revealed that Cu(II) cation had remarkable fluorescence quenching effect during complex formation with L2 and L3 , while Zn(II) displayed noticeable enhancement on the fluorescence emission of L1 and L4 , respectively. Fluorescence quantum yields of Ln (L1-L4 ) as well as their complexes Ln /M (II) (M=Cu, and Zn) were found as 0.11-0.34, respectively. The complementary experiments on determination of the limit of detection indicated (LOD) that L2 and L3 were highly selective for detection of Cu(II) while L1 and L4 were selective towards Zn(II), respectively. Using Benesi-Hildebrand... 

To find metal ion recognition by L (L = O2N2-donor naphthodiaza-crown macrocyclic ligand), the complexes [ML]2+ (M = Cd, Hg and Pb) were synthesized and characterized by IR, 1H, 13C NMR, and mass spectrometry, as well as elemental microanalysis. Hg(II) showed perceptible enhancement of the fluorescence of L in which ultra-low limit of detection for Hg(II) by L was determined as 1 nM in ethanol and DMSO. L reserved selectivity of Hg(II) in its binary mixtures with metal cations in solution. A 1 : 1 stoichiometry was found for the interaction of Hg(II) with L while Benesi–Hildebrand method was applied to calculate its complexation binding constant (K BH) employing fluorescence... 

Fluorescence spectroscopy of a series of N2O2-donor naphthodiaza-crown macrocyclic ligands, L1-L4, in ethanol revealed that Cu(II) cation had remarkable fluorescence quenching effect during complex formation with L2 and L3, while Zn(II) displayed noticeable enhancement on the fluorescence emission of L1 and L4, respectively. Fluorescence quantum yields of Ln (L1-L4) as well as their complexes Ln/M (II) (M = Cu, and Zn) were found as 0.11–0.34, respectively. The complementary experiments on determination of the limit of detection indicated (LOD) that L2 and L3 were highly selective for detection of Cu(II) while L1 and L4 were selective towards Zn(II), respectively. Using Benesi–Hildebrand... 

The noticeable enhancement in fluorescence emission of O2N2-donor naphthodiaza-crown macrocyclic ligand (L) in the presence of Hg2+ was observed in which the fluorescence quantum yield of free ligand L as well as L/Hg2+ complex were found to be as 0.29 and 0.49, respectively. The observed ultra-low limit of detection (LOD) for Hg2+ by L was determined as low as 1.0 × 10−11 M in water. A 1:1 stoichiometry was also established for L/Hg2+ together with a binding constant KBH = 66,543 by employing fluorescence spectrophotometry. The competition experiments on L/Hg2+ demonstrated highly selective detection of Hg2+ in the presence of the library cations. A two path mechanism for detection of metal... 

A novel high selective colorimetric chemosensor was introduced based on a nano diphenyl-based Schiff base (H2L), 2,2′-((1E,1′E)-(((hexylazanediyl)bis(4,1-phenylene))bis(methanylylidene))bis(azanylylidene))bis(4-methylphenol) that synthesized using sonochemical method. H2L was characterized by FT-IR, MS, TGA, 1H NMR, 13C NMR, SEM and elemental analysis techniques, then fabricated as the portable strips for sensing copper (II) ions in aqueous media. The binding interaction between H2L and various metal ions was investigated by UV–Vis spectroscopic that showed favorable coordination toward Cu2+ ion. H2L exhibited binding-induced color changes from yellow to pink and practically no interference... 

Two new macrocyclic ligands Ln (L and L′) bearing two fluorophore naphthalene moieties were synthesized and characterized by employing 1H and 13C NMR, IR, microanalysis as well as mass spectrometry. Comparative studies on the effect of assorted metal cations as Cr(III), Cu(II), Zn(II), Cd(II), Pb(II), Na(I), Ni(II), Co(II), Ba(II), Fe(II), Al(III), Mg(II), Cs(I), Ca(II), Hg(II), K(I), Mn(II), Ag(I), Fe(III) on fluorescence and UV–vis spectra of Ln in ethanol illustrated that both of the macrocycles were sensitive and selective fluorescence chemosensors for Al(III). Remarkable binding constant values as 1.36 × 105 M−1 and 1.15 × 105 M−1 alongside 1:1 stoichiometry for Al(III)/L and Al(III)/L′... 

Two new macrocyclic ligands Ln (L and L′) bearing two fluorophore naphthalene moieties were synthesized and characterized by employing 1H and 13C NMR, IR, microanalysis as well as mass spectrometry. Comparative studies on the effect of assorted metal cations as Cr(III), Cu(II), Zn(II), Cd(II), Pb(II), Na(I), Ni(II), Co(II), Ba(II), Fe(II), Al(III), Mg(II), Cs(I), Ca(II), Hg(II), K(I), Mn(II), Ag(I), Fe(III) on fluorescence and UV–vis spectra of Ln in ethanol illustrated that both of the macrocycles were sensitive and selective fluorescence chemosensors for Al(III). Remarkable binding constant values as 1.36 × 105 M−1 and 1.15 × 105 M−1 alongside 1:1 stoichiometry for Al(III)/L and Al(III)/L′... 

Herein, we describe for the first time synthesis, characterization, chemosenor behavior, and mechanism of metal ion-ligand interaction of two novel side-armed naphthodiaza-crown macrocycles (L1 and L2) by employing of IR, 1H and 13C NMR, UV–vis, fluorescence spectroscopy, CHN microanalysis and single crystal X-ray diffraction. Preliminary fluorescence studies in ethanol as solvent revealed that the metal ion recognition by L1 was strongly different from L2 suggesting the importance of the number of benzylic side-arms on the extent of the interaction with Mn+. For instance employing fluorescence titration in ethanol showed binding constant values 105 M−1 and 2.6×106 M−1 for L1/Al3+ and...