71000-82-3Relevant articles and documents
Synthesis, application and AIE properties of novel fluorescent tetraoxocalix[2]arene[2]triazine: The detection of a hazardous anion, cyanate
Bozkurt, Selahattin,Halay, Erkan
, (2020/10/19)
A highly effective, new heterocalixarene fluorescent receptor comprised of 2-(2-aminophenyl)benzothiazole and tetraoxacalix[2]arene[2]triazine was designed and synthesized by one-step reaction. The sensor candidate exhibiting aggregation induced emission (AIE) was tested for its photophysical behaviour towards detection of various anions. The results showed that our receptor undergo AIE in >40% H2O-DMSO along with large pseudo Stokes shift (Δλ = 219 nm) and exhibit selective and sensitive detection towards hazardous cyanide's oxidation product, cyanate (CNO-) ion over other tested anions. The blue-shifted fluorescence emission (λem = 492 nm) enhancement with large Stokes shift (Δλ = 144 nm) was observed with the increase in cyanate concentration. The synthesized turn-on sensor towards cyanate detection could be applied in real sample analyses as an improvement to the method currently carried out by international standards and hereby a different approach has been made for the detection of cyanide through its oxidation form, cyanate.
Catalyst displacement assay: A supramolecular approach for the design of smart latent catalysts for pollutant monitoring and removal
Chow, Cheuk-Fai,Ho, Pui-Yu,Wong, Wing-Leung,Lu, Yu-Jing,Tang, Qian,Gong, Cheng-Bin
, p. 3812 - 3820 (2017/07/11)
Latent catalysts can be tuned to function smartly by assigning a sensing threshold using the displacement approach for targeted analytes. Three cyano-bridged bimetallic complexes were synthesized as smart latent catalysts through the supramolecular assembly of different metallic donors [FeII(CN)6]4-, [FeII(tBubpy)(CN)4]2-, and FeII(tBubpy)2(CN)2 with a metallic acceptor [CuII(dien)]2+. The investigation of both their thermodynamic and kinetic properties on binding with toxic pollutants provided insight into their smart off-on catalytic capabilities, enabling us to establish a threshold-controlled catalytic system for the degradation of pollutants such as cyanide and oxalate. With these smart latent catalysts, a new catalyst displacement assay (CDA) was demonstrated and applied in a real wastewater treatment process to degrade cyanide pollutants in both domestic (level I, untreated) and industrial wastewater samples collected in Hong Kong, China. The smart system was adjusted to be able to initiate the catalytic oxidation of cyanide at a threshold concentration of 20 μM (the World Health Organization's suggested maximum allowable level for cyanide in wastewater) to the less harmful cyanate under ambient conditions.
A Multifunctional Bimetallic Molecular Device for Ultrasensitive Detection, Naked-Eye Recognition, and Elimination of Cyanide Ions
Chow, Cheuk-Fai,Ho, Pui-Yu,Wong, Wing-Leung,Gong, Cheng-Bin
, p. 12984 - 12990 (2015/09/07)
A new bimetallic FeII-CuII complex was synthesized, characterized, and applied as a selective and sensitive sensor for cyanide detection in water. This complex is the first multifunctional device that can simultaneously detect cyanide ions in real water samples, amplify the colorimetric signal upon detection for naked-eye recognition at the parts-per-million (ppb) level, and convert the toxic cyanide ion into the much safer cyanate ion in situ. The mechanism of the bimetallic complex for high-selectivity recognition and signaling toward cyanide ions was investigated through a series of binding kinetics of the complex with different analytes, including CN-, SO42-, HCO3-, HPO42-, N3-, CH3COO-, NCS-, NO3-, and Cl- ions. In addition, the use of the indicator/catalyst displacement assay (ICDA) is demonstrated in the present system in which one metal center acts as a receptor and inhibitor and is bridged to another metal center that is responsible for signal transduction and catalysis, thus showing a versatile approach to the design of new multifunctional devices.
Designed hierarchical synthesis of ring-shaped Bi2WO 6@CeO2 hybrid nanoparticle aggregates for photocatalytic detoxification of cyanide
Guo, Hong,Guo, Yuanyuan,Liu, Lixiang,Li, Tingting,Wang, Wei,Chen, Weiwei,Chen, Jing
, p. 2539 - 2545 (2014/05/06)
Ring-shaped Bi2WO6@CeO2 hybrid nanoparticle aggregates are fabricated through an environmental route and subsequent facile calcinations. The synthetic parameters are regulated to control the shape of the as-prepared samples. The concentration of the cyanide ion decreased sharply from the initial 4.72 mM to 0.95 mM with the exposure time of 60 min. The intrinsic ring-shaped microstructure results in multiple reflections of light within the chamber, allowing more efficient use of the light source compared with a solid structure. The p-n junction effect can lead to enhanced charge separation and interfacial charge transfer efficiency due to the existence of an internal electric field. Therefore, it exhibits a remarkable photocatalytic detoxification of cyanide and degradation of dye under visible light. the Partner Organisations 2014.
Oxidation of thiocyanate with H2O2 catalyzed by [RuIII(edta)(H2O)]-
Chatterjee, Debabrata,Paul, Barnali,Mukherjee, Rupa
supporting information, p. 10056 - 10060 (2013/08/23)
The [RuIII(edta)(H2O)]- (edta4- = ethylenediaminetetraacetate) complex is shown to catalyze the oxidation of thiocyanate (SCN-) with H2O2 mimicking the action of peroxidases. The kinetics of the catalytic oxidation process was studied by using stopped-flow and rapid scan spectrophotometry as a function of [RuIII(edta)], [H2O2], [SCN-], pH (3.2-9.1) and temperature (15-30 °C). Spectral analyses and kinetic data are suggestive of a catalytic pathway in which hydrogen peroxide reacts directly with thiocyanate coordinated to the RuIII(edta) complex. Catalytic intermediates such as [RuIII(edta)(OOH)]2- and [Ru V(edta)(O)]- were found to be non-reactive in the oxidation process under the specified conditions. Formation of SO 42- and OCN- was identified as oxidation products in ESI-MS experiments. A detailed mechanism in agreement with the spectral and kinetic data is presented. The Royal Society of Chemistry 2013.
Mechanism of decomposition of the human defense factor hypothiocyanite near physiological pH
Kalmar, Jozsef,Woldegiorgis, Kelemu L.,Biri, Bernadett,Ashby, Michael T.
, p. 19911 - 19921 (2012/01/31)
Relatively little is known about the reaction chemistry of the human defense factor hypothiocyanite (OSCN-) and its conjugate acid hypothiocyanous acid (HOSCN), in part because of their instability in aqueous solutions. Herein we report that HOSCN/OSCN- can engage in a cascade of pH- and concentration-dependent comproportionation, disproportionation, and hydrolysis reactions that control its stability in water. On the basis of reaction kinetic, spectroscopic, and chromatographic methods, a detailed mechanism is proposed for the decomposition of HOSCN/OSCN- in the range of pH 4-7 to eventually give simple inorganic anions including CN -, OCN-, SCN-, SO32-, and SO42-. Thiocyanogen ((SCN)2) is proposed to be a key intermediate in the hydrolysis; and the facile reaction of (SCN) 2 with OSCN- to give NCS(=O)SCN, a previously unknown reactive sulfur species, has been independently investigated. The mechanism of the aqueous decomposition of (SCN)2 around pH 4 is also reported. The resulting mechanistic models for the decomposition of HOSCN and (SCN) 2 address previous empirical observations, including the facts that the presence of SCN- and/or (SCN)2 decreases the stability of HOSCN/OSCN-, that radioisotopic labeling provided evidence that under physiological conditions decomposing OSCN- is not in equilibrium with (SCN)2 and SCN-, and that the hydrolysis of (SCN)2 near neutral pH does not produce OSCN-. Accordingly, we demonstrate that, during the human peroxidase-catalyzed oxidation of SCN-, (SCN)2 cannot be the precursor of the OSCN- that is produced.
Ambident reactivity of the cyanate anion
Schaller, Heike F.,Schmidhammer, Uli,Riedle, Eberhard,Mayr, Herbert
supporting information; experimental part, p. 3866 - 3868 (2009/05/07)
A study was conducted to investigate ambident reactivity of the cyanate anion. The study showed that the cyanate anion is an ambident nucleophile, which may react with electrophiles either at the oxygen terminus, to yield alkyl cyanates, or at the nitrogen terminus, to yield isocyanates. Equal amounts of alkyl cyanates and isocyanates were obtained, when secondary iodoalkynes were treated with silver cyanate and the formation of tert-butyl isocyanate, along with 2-methylpropene and cyanic acid. The study also investigated the possibility of SN1 reactions of cyanates proceeding with charge control to give cyanates.
Solubility, complex formation, and redox reactions in the Tl 2O3-HCN/CN--H2O system. Crystal structures of the cyano compounds Tl(CN)3·H2O, Na[Tl(CN)4]·3H2O, K[Tl(CN)4], and TlITlIII(CN)4 and of TlI 2C2O
Nagy, Peter,Fischer, Andreas,Glaser, Julius,Ilyukhin, Andrey,Maliarik, Mikhail,Toth, Imre
, p. 2347 - 2357 (2008/10/09)
Thallium(III) oxide can be dissolved in water in the presence of strongly complexing cyanide ions. TlIII is leached from its oxide both by aqueous solutions of hydrogen cyanide and by alkali-metal cyanides. The dominating cyano complex of thallium(III) obtained by dissolution of Tl 2O3 in HCN is [Tl(CN)3(Bq)] as shown by 205Tl NMR. The Tl(CN)3 species has been selectively extracted into diethyl ether from aqueous solution with the ratio CN -/TlIII = = 3. When aqueous solutions of the MCN (M = Na+, K+) salts are used to dissolve thallium(III) oxide, the equilibrium in liquid phase is fully shifted to the [Tl(CN) 4]- complex. The Tl(CN)3 and Tl(CN) 4- species have for the first time been synthesized in the solid state as Tl(CN)3·H2O (1), M[Tl(CN) 4] (M = Tl (2) and K (3)), and Na[Tl(CN)4]·3H 2O (4) salts, and their structures have been determined by single-crystal X-ray diffraction. In the crystal structure of 1, the thallium(III) ion has a trigonal bipyramidal coordination with three cyanide ions in the equatorial plane, while an oxygen atom of the water molecule and a nitrogen atom from a cyanide ligand, attached to a neighboring thallium complex, form a linear O-Tl-N fragment. In the three compounds of the tetracyano-thallium(III) complex, 2-4, the [Tl(CN)4]- unit has a distorted tetrahedral geometry. Along with the acidic leaching (enhanced by TlIII-CN- complex formation), an effective reductive dissolution of the thallium(III) oxide can also take place in the Tl 2O3-HCN-H2O system yielding thallium(I), while hydrogen cyanide is oxidized to cyanogen. The latter is hydrolyzed in aqueous solution giving rise to a number of products including (CONH2) 2, NCO-, and NH4+ detected by 14N NMR. The crystalline compounds, TlI[Tl III(CN)4], TlI2C2O 4, and (CONH2)2, have been obtained as products of the redox reactions in the system.
Photocatalytic oxidation of cyanide: Kinetic and mechanistic studies
Chiang,Amal,Tran
, p. 285 - 297 (2008/10/08)
The kinetics and mechanism of the photocatalytic oxidation of cyanide in the presence titanium dioxide catalyst were investigated in this study. By displacing the surface hydroxyl groups on the surface of titanium dioxide with fluoride ions, it was deduced that cyanide is oxidised via a pure heterogeneous pathway, i.e. oxidised by the holes trapped at the surface hydroxyl groups ≡TiO.. The quantum efficiency of the photocatalytic oxidation was found to be low (ca. 0.1-0.2%) and this was mainly due to (1) the low adsorption of cyanide ions onto the titanium dioxide surface, (2) the absence of homogenous reaction between cyanide ions and diffused hydroxyl radicals, and (3) the high electron hole recombination rate within the titanium dioxide photocatalyst. A kinetic model was developed to describe the mechanism involved in the photocatalytic oxidation of cyanide.
Thermal reactivity of HNCO with water ice: An infrared and theoretical study
Raunier, Sébastien,Chiavassa, Thierry,Allouche, Alain,Marinelli, Francis,Aycard, Jean-Pierre
, p. 197 - 210 (2008/10/08)
The structure and energy of the 1:1 complexes between isocyanic acid (HNCO) and H2O are investigated using FTIR matrix isolation spectroscopy and quantum calculations at the MP2/6-31G(d,p) level. Calculations yield two stable complexes. The first and most stable one (ΔE = 23.3 kJ/mol) corresponds a form which involves a hydrogen bond between the acid hydrogen of HNCO and the oxygen of water. The second form involves a hydrogen bond between the terminal oxygen of HNCO and hydrogen of water. In an argon matrix at 10 K, only the first form is observed. Adsorption on amorphous ice water at 10 K shows the formation of only one adsorption site between HNCO and ice. It is comparable to the complex observed in matrix and involves an interaction with the dangling oxygen site of ice. Modeling using computer code indicates the formation of polymeric structure on ice surface. Warming of HNCO, adsorbed on H2O ice film or co-deposited with H2O samples above 110 K, induces the formation of isocyanate ion (OCN-) characterized by its vasNCO infrared absorption band near 2170 cm-1. OCN- can be produced by purely solvation-induced HNCO dissociative ionization. The transition state of this process is calculated 42 kJ/mol above the initial state, using the ONIOM model in B3LYP/6-31g(d,p).
