2150-02-9Relevant articles and documents
A highly selective fluorescent sensor for mercury ion (II) based on azathia-crown ether possessing a dansyl moiety
Dai, Huajun,Liu, Fei,Gao, Qianqian,Fu, Tianhua,Kou, Xingming
, p. 523 - 530 (2011)
An intramolecular charge transfer (ICT) fluorescent sensor 1 using a dansyl moiety as the fluorophore and an azathia-crown ether as the receptor was designed, synthesized and characterized. The ions-selective signaling behaviors of the sensor 1 were investigated in CH3CN-H2O (1:1, v/v) by fluorescence spectroscopy. It exhibited remarkable fluorescence quenching upon addition of Hg2+, which was attributed to the 1:1 complex formation between 1 and Hg2+, while other selected metal ions induced basically no spectral changes. The sensor 1 showed a rapid and linear response towards Hg2+ in the concentration range from 5.0 × 10 -7 to 1.0 × 10-5 mol L-1 with the detection limit of 1.0 × 10-7 mol L-1. Furthermore, the whole process could be carried out in a wide pH range of 2.0-8.0 and was not disturbed by other metal ions. Thus, the sensor 1 was used for practical determination of Hg2+ in different water samples with satisfactory results. Copyright
A highly selective and sensitive fluorescent sensor for copper(ii) ion characterized by one dichlorofluorescein moiety and two azathia-crown ether
Jiang, Y,Huang, Zhong,Dai, Huajun,Wang, Lihua,Ying, Liu,Kou, Xingming
, p. 8292 - 8296 (2013)
A new fluorescent sensor 1, which functionalized with one dichlorofluorescein moiety as fluorogenic signaling subunit and two azathiacrown ether macrocyclic as binding site was designed, synthesized and characterized. It was found that sensor 1 can selectively recognize Cu2+ by a remarkable emission quenching in DMSO-H2O (1:1, v/v), which was attributed to the 1:2 complex formation between 1 and Cu2+, while other ion including K+, Na+, Mg2+, Zn 2+, Ba2+, Co2+, Ca2+, Fe 2+, Fe3+, Pb2+, Pb2+, Ni 2+ and Ag+ induced no or much small fluorescence changes. In addition, the sensor 1 exihibited a rapid, stable and linear response to Cu2+ in the concentration range from 5 × 10-7 to 1 × 10-5 mol L-1 with a detection limit as low as 8.7 × 10-8 mol L-1. Furthermore, the sensor 1 was applied to practical determination of Cu2+ in different water samples with satisfactory results.
Application of HPLC for the screening of separation of new macrocyclic systems
Stefaniak, Monika,Romański, Jaros?aw
, p. 245 - 248 (2017/01/22)
The efficient synthesis of new macrocyclic systems via nucleophilic ring opening reaction of epoxides by thiols was described. Initially new macrocyclic compounds were obtained as a mixture of diastereomers. Preparative thin layer chromatography was applied to separate meso and pairs of enantiomer. The identification of products using a chiral HPLC column and mass spectroscopy was utilized.
Optimized methods for preparation of 6I-(ω-sulfanyl-alkylenesulfanyl)-β-cyclodextrin derivatives
Bedná?ová, Eva,Hybelbauerová, Simona,Jind?ich, Jind?ich
supporting information, p. 349 - 352 (2016/04/05)
A general high-yielding method for the preparation of monosubstituted β-cyclodextrin derivatives which have attached a thiol group in position 6 is described. The thiol group is attached through linkers of different lengths and repeating units (ethylene glycol or methylene). The target compounds were characterized by IR, MS and NMR spectra. A simple method for their complete conversion to the corresponding disulfides as well as a method for the reduction of the disulfides back to the thiols is presented. Both, thiols and disulfides are derivatives usable for well-defined covalent attachment of cyclodextrin to gold or polydopamine-coated solid surfaces.
Single-step synthesis of internally functionalizable hyperbranched polyethers
Roy, Raj Kumar,Ramakrishnan
, p. 4125 - 4135 (2013/09/23)
Radical catalyzed thiol-ene reaction has become a useful alternative to the Hüisgen-type azide-yne click reaction as it helps expand the variability in reaction conditions as well as the range of clickable entities. In this study, the direct generation of a hyperbranched polyether (HBPE) having decyl units at the periphery and a pendant allyl group on every repeat unit of the polymer backbone is described; the allyl groups serve as a reactive handle for postpolymerization modifications and permits the generation of a variety of internally functionalized HBPEs. In this design, the AB2 monomer carries two decylbenzyl ether units (B-functionality), an aliphatic -OH (A-functionality) and a pendant allyl group within the spacer segment; polymerization of the monomer readily occurs at 150 °C via melt transetherification process by continuous removal of 1-decanol under reduced pressure. The resulting HBPE has a hydrophobic periphery due to the presence of numerous decyl chains, while the allyl groups that remain unaffected during the melt polymerization provides an opportunity to install a variety of functional groups within the interior; thiol-ene click reaction with two different thiols, namely 3-mercaptopropionic acid and mercaptosuccinic acid, generated interesting amphiphilic structures. Preliminary field emission scanning electron microscope (FESEM) and Atomic Force Microscopy (AFM) imaging studies reveal the formation of fairly uniform spherical aggregates in water with sizes ranging from 200 to 400 nm; this suggests that these amphiphilic HBPs is able to reconfigure to generate jellyfish-like conformations that subsequently aggregate in an alkaline medium. The internal allyl functional groups were also used to generate intramolecularly core-crosslinked HBPEs, by the use of dithiol crosslinkers; gel permeation chromatography traces provided clear evidence for reduction in the size after crosslinking. In summary, we have developed a simple route to prepare core-clickable HBPEs and have demonstrated the quantitative reaction of the allyl groups present within the interior of the polymers; such HB polymeric systems that carry numerous functional groups within the core could have interesting applications in analyte sequestration and possibly sensing, especially from organic media.
Synthesis of acyclic, symmetrical 3,3'-allyl dithioethers, from the alkylation of 3-mercapto-2-mercaptomethylprop-1-ene in the presence of sodium hydride
Moorhoff, Cornelis M.,Cook, Wayne D.,Chen, Fei,Nghiem, Dat,Braybrook, Carl,Thang, San H.,Sun, Jiazeng,Scott, Timothy F.,Bowman, Christopher N.
body text, p. 1083 - 1093 (2011/11/07)
A novel method where 3,3'-allyl dithioethers have been prepared from 3-mercapto-2-mercaptomethylprop-1-ene and two mol equivalent of alkyl halide in the presence of two mol equivalent of sodium hydride has been developed. Using this method, bisepoxide, 2,2'-(2-methylenepropane-1,3-diyl)bis(sulfanediyl) bis(methylene)dioxirane (8) has been synthesized from epichlorohydrin, whereas potassium carbonate was unable to deliver this product. These 3,3'-allyl dithioethers can be utilized either as monomers, or with further chemical reactions transformed into more complex monomers, for photoplastic polymer networks.
Reactions of bielectrophiles (ClCH2CH2)2Y with sulfur in basic reducing systems
Korchevin,Russavskaya,Alekminskaya,Deryagina
, p. 240 - 243 (2007/10/03)
A simple procedure was developed for preparing bis(β-mercaptoethyl) ether and bis(β-mecraptoethyl) sulfide from commercially available chemicals: elemental sulfur, alkali, and bis(β-chloroethyl) ether or sulfide, based on thiylation with elemental sulfur of these substrates in the aqueous system hydrazine hydrate-alkali, with initial formation of the corresponding polysulfide polymers (thiokols). Their reduction with the system hydrazine hydrate-alkali, followed by acidification of dithiolate anions, yields the corresponding dithiols. Thiokols based on bis(β-chloroethyl) ether are soluble in organic solvents; they were studied by 1H NMR.
The synthesis and complexation studies of thia-anthracene receptors
Ostaszewski, Ryszard,Prodi, Luca,Montalti, Marco
, p. 11553 - 11562 (2007/10/03)
Systematic studies towards the formation of thia-anthracene receptors were performed. Anthracene podand 3 consisting of two anthryl groups connected by the SCH2CH2CH2S spacer group was prepared in 99% yield. The complexation properties of this compound were investigated using UV-VIS and fluorescence titration techniques. Addition of silver salts into a solution of the fluorophore strongly modifies the absorption and fluorescence spectra and the association constants were found to be K1 = 2 x 105 and K2 = 8 x 104 M-1 for the 1:1 and 1:2 complexes, respectively. Addition of metal ions, as Cu2+ Zn2+, Cd2+, Hg2+, Ni2+, and Co2+, did not lead to any change in the photophysical properties of compound 3.
Polyfunctional disulfide compounds having S--S exchange reactivity
-
, (2008/06/13)
A polyfunctional disulfide compound, useful as a cross-linking reagent having S--S exchange reactivity, of the formula STR1 wherein R is 2-benzothiazolyl or 2-pyridyl-N-oxide and X is a spacer group having an alkylene group directly bonded to each S--S group.
Rate Constants and Equilibrium Constants for Thiol-Disulphide Interchange Reactions Involving Oxidized Glutathione
Szajewski, Richard P.,Whitesides, George M.
, p. 2011 - 2026 (2007/10/02)
The rate of reduction of oxidized glutathione (GSSG) to glutathione (GSH) by thiolate (RS-) follows a Broensted relation in pKas of the conjugate thiols (RSH): βnuc ca. 0.5.This value is similar to that for reduction of Ellman's reagent: βnuc ca. 0.4 - 0.5.Analysis of a number of rate and equilibrium data, taken both from this work and from the literature, indicates that rate constants, k, for a range of thiolate-disulphide interchange reactions are correlated well by equations of the form log k = C + βnucpKanuc + βcpKac + βlgpKalg ( nuc = nucleophile, c = central, and lg = leaving group sulfur): eq 36 - 38 give representative values of the Broensted coefficients.The values of these Bronsted coefficients are not sharply defined by the available experimental data, although eq 36 - 38 provide useful kinetic models for rates of thiolate-disulfide interchange reactions.The uncertainty in these parameters is such that their detailed mechanistic interpretation is not worthwhile, but their qualitative interpretation - that all three sulphur atoms experience a significant effective negative charge in the transition state, but that the charge is concentrated on the terminal sulfurs - is justified.Equilibrium constants for reduction of GSSG using α,ω-dithiols have been measured.The reducing potential of the dithiol is strongly influenced by the size of the cyclic disulfide formed on its oxidation: the most strongly reducing dithiols are those which can form six-membered cyclic disulfides.Separate equilibrium constants for thiolate anion-disulphide interchange (KS-) and for thiol-disufide interchange (KSH) have been estimated from literature data: KS- is roughly proportional to 2ΔpKa is the difference between the pKas of the two thiols involved in the interchange.The contributions of thiol pKa values to the observed equilibrium constants for reduction of GSSG with α,ω-dithiols appear to be much smaller than those ascribable to the influence of structure on intramolecular ring formation.These equilibrium and rate constants are helpful in choosing dithiols for use as antioxidants in solutions containing proteines: dithiothreitol (DTT), 1,3-dimercapto-2-propanol (DMP), and 2-mercaptoethanol have especially useful properties.
