- Ratiometric and selective fluorescent sensor for Zn2+ as an "off-on-off" switch and logic gate
-
A new chemosensor, 2,3,15,16-tetrakis(pyridin-2-yl)-7,8,10,11,20,21,23,24- octahydro[1,4,7,10,13,16]hexaoxacyclooctadecino[2,3-g:11,12-g′] diquinoxaline (1), containing 2,3-bis(pyridin-2-yl)quinoxaline and crown ether moieties, has been designed and found to be a ratiometric and selective fluorescent detector of Zn2+ over a wide range of tested metal ions. The addition of Zn2+ to the solution of 1 in acetonitrile induced the formation of a 1:2 ligand-metal complex, 1-Zn2+, which exhibits a remarkable enhanced fluorescent emission centered at 460 nm, with the disappearance of the fluorescent emission of 1 centered at 396 nm due to the mechanism of internal charge transfer. In contrast, the presence of K + results in the fluorescence quenching of 1 and 1-Zn2+ through the photoinduced electron-transfer mechanism. These results demonstrate that 1 can perform as not only an INHIBIT logic gate but also an "off-on-off" molecular switch triggered by Zn2+ and K +. The structure of complex 1-Zn2+ has been characterized by single-crystal X-ray crystallography, mass spectrometry, and 1H NMR titration experiments. Density functional theory calculation results on 1 and the 1-Zn2+ complex are well consistent with the experimental results.
- Li, Ya-Ping,Yang, Hua-Rong,Zhao, Qiang,Song, Wei-Chao,Han, Jie,Bu, Xian-He
-
-
Read Online
- Lead ion selective electrodes from dibenzo-18-crown-6 derivatives: An exploratory study
-
Dibenzo-18-crown-6 (DB18C6) and three of its derivatives (-COCH3, -Br, -NO2), are investigated via Density Functional Theoretical (DFT) modelling, Fourier Transform Infrared (FT-IR) and absorption spectroscopies, Differential Pulse Anodic Stripping (DPASV), Cyclic (CV) and Square Wave (SWV) voltammetries, as possible materials for preparing plasticiser free lead(II) ion selective electrodes. The spontaneous, entropy driven, interactions between lead(II) ions and DB18C6 derivatives are such that they form 1:1 complexes via coordination with the high electron density open ether cavity, except for the brominated derivative where the metal: ligand stoichiometry is 2:1 due to exo-cavity coordination via the high electron density bromine atoms. Monolayers resulting from electropolymerization of some derivatives (-H, -COCH3, -Br) and chemisorption of the -NO2 derivative, allows quantification of lead(II) ions at concentrations below 10 mg L?1 with minimal interference from other metal ions except Hg2+ and Al3+.
- Jackson, Deneikah T.,Nelson, Peter N.,Booysen, Irvin N.
-
-
- A fluorescent and colorimetric sensor for Al3+ based on a dibenzo-18-crown-6 derivative
-
A new receptor based on a dibenzo-18-crown-6 derivative is successfully synthesized and characterized. This receptor reveals selective recognition toward Al3+ ion, along with colorimetric and fluorometric dual-signaling responses based on internal charge transfer (ICT). Also, it can serve as a highly selective chemodosimeter for Al3+ with naked-eye detection.
- Li, Ya-Ping,Liu, Xiu-Ming,Zhang, Ying-Hui,Chang, Ze
-
-
- Lipophilic metal-salicylideneimine-crown ether hybrids - Ditopic carriers in the facilitated transport of amphiphilic molecules across bulk liquid membranes
-
The crown ether-functionalized MnIII salicylaldimine complexes manganese (III) 4,5-bis (3,5-di-tert-butylsalicylideneimine)benzo-18-crown-6-X [X = Cl-, I-, CH3COO-,(CH3)3CCOOsup
- Pike, Jay D.,Rosa, Dell T.,Coucouvanis, Dimitri
-
p. 761 - 777
(2007/10/03)
-
- Synthesis of di- and tetraamino-substituted dibenzo-18-crown-6 and some nitrogen-containing heterocycles based thereon
-
New procedures were developed for synthesis of di- and tetraamino-substituted derivatives of dibenzo-18-crown-6, which were used for preparation of some new nitrogen-containing heterocycles.
- Ovchinnikova,Fedorova,Rusinov
-
p. 1082 - 1085
(2007/10/03)
-
- SYNTHESIS OF NITRO DERIVATIVES OF DIBENZO-18-CROWN-6
-
The reaction of dibenzo-18-crown-6 with nitric acid in the presence of lanthanum nitrate in acetonitrile led to the production of its nitro derivative 20,25-dinitro-2,3,11,12-dibenzo-1,4,7,10,13,16-hexaoxacyclooctadeca-2,11-diene.Possible paths for the synthesis of the mono- and trinitro derivatives of dibenzo-18-crown are analyzed.
- Kalishevich, V. S.,Timofeev, O. S.,Zakharov, K. S.,Gren', A. I.
-
p. 349 - 353
(2007/10/02)
-