1111-68-8Relevant academic research and scientific papers
Kinetics and Products of the Reactions of NO3 with Monoalkenes, Dialkenes, and Monoterpenes
DeFelippis, Michael R.,Faraggi, M.,Klapper, Michael H.
, p. 2420 - 2424 (1990)
Rate constants for the reactions of NO3 with a number of aliphatic mono- and dialkenes and monoterpenes have been determined in a 420 l reaction chamber at 1-bar total pressure of synthetic air by 298 K with a relative kinetic method.The products of these reactions have been investigated also at 1-bar total pressure of synthetic air with in situ FT-IR spectrometry and gas chromatography.In all cases, the initial formation of thermally unstable nitrooxy-peroxynitrate-type compounds containing the difunctional group -CH(OONO2)-CH(ONO2)- has been observed.The experimental results are consistent with a mechanism involving the formation of nitrooxy-alkoxy radicals, -CH(O)-CH(ONO2)-, via the self-reaction of the nitrooxy-peroxy radicals.The further reactions of the nitrooxy-alkoxy radicals then determine the final products.The main reaction pathways are (i) reaction with O2 to form nitrooxy-aldehydes or -ketones and HO2 and (II) thermal decomposition forming aldehydes/ketones and NO2.The mechanisms leading to the final products are discussed, and their possible relevance for the chemistry in the troposphere is considered.
Water-Soluble α-Amino Acid Complexes of Molybdenum as Potential Antidotes for Cyanide Poisoning: Synthesis and Catalytic Studies of Threonine, Methionine, Serine, and Leucine Complexes
Gretarsdottir, Johanna M.,Hambley, Trevor W.,Jonsdottir, Sigridur,Lewis, William,Suman, Sigridur G.
, p. 18190 - 18204 (2020)
Water-soluble complexes are desirable for the aqueous detoxification of cyanide. Molybdenum complexes with α-amino acid and disulfide ligands with the formula K[(L)Mo2O2(μ-S)2(S2)] (L = leu (1), met (2), thr (3), and ser (4)) were synthesized in a reaction of [(DMF)3MoO(μ-S)2(S2)] with deprotonated α-amino acids; leu, met, thr, and ser are the carboxylate anions of l-leucine, l-methionine, l-threonine, and l-serine, respectively. Potassium salts of α-amino acids (leu (1a), met (2a), thr (3a), and ser (4a)) were prepared as precursors for complexes 1-4, respectively, by employing a nonaqueous synthesis route. The ligand exchange reaction of [Mo2O2(μ-S)2(DMF)6](I)2 with deprotonated α-amino acids afforded bis-α-amino acid complexes, [(L)2Mo2O2(μ-S)2] (6-8). A tris-α-amino acid complex, [(leu)2Mo2O2(μ-S)2(μ-leu + H)] (5; leu + H is the carboxylate anion of l-leucine with the amine protonated), formed in the reaction with leucine. 5 crystallized from methanol with a third weakly bonded leucine as a bridging bidentate carboxylate. An adduct of 8 with SCN - coordinated, 9, crystallized and was structurally characterized. Complexes 1-4 are air stable and highly water-soluble chiral molecules. Cytotoxicity studies in the A549 cell line gave IC50 values that range from 80 to 400 μM. Cyclic voltammetry traces of 1-8 show solvent-dependent irreversible electrochemical behavior. Complexes 1-4 demonstrated the ability to catalyze the reaction of thiosulfate and cyanide in vitro to exhaustively transform cyanide to thiocyanate in less than 1 h.
Velocity modulation diode laser spectroscopy of negative ions: The ν1 + ν2 - ν2, ν1 +ν3-ν3 bands of thiocyanate (NCS-)
Polak, Mark,Gruebele, Martin,Saykally, Richard J.
, p. 3352 - 3356 (1987)
149 transitions in the ν1 band (CN stretch) and the corresponding bending and stretching hot bands of thiocyanate (NCS-) have been measured using velocity modulation spectroscopy with a tunable diode laser.The data were fit to an effective rotation-vibration Hamiltonian, yielding spectroscopic parameters for the ( 000 ), ( 100 ) , ( 010 ) , ( 110 ) , ( 001 ), and ( 101 ) vibrational states.The band origin is ν1 = 2065.9312(13) cm-1 and the equilibrium rotational constant is calculated to be 0.197 438(61) cm-1.NCS- was prepared in a NH3/CS2 discharge, and unlike the recently studied case of NCO-, vibrational excitation in excess of the rotational temperature ( 650+/-200 K ) was not observed.
Temperature dependence of (SCN)2?- in water at 25-400°C: Absorption spectrum, equilibrium constant, and decay
Wu, Guozhong,Katsumura, Yosuke,Muroya, Yusa,Lin, Mingzhang,Morioka, Tomomi
, p. 4933 - 4939 (2001)
The temperature dependence of the absorption spectrum of the formation and decay of (SCN)2?-, a well-characterized dimer anion, was investigated at temperatures from 25 to 400°C. The absorption peak was found to shift to longer wavelength with temperature (red shift), from 470 nm at 25°C to 510 nm at 400°C. The equilibrium constants K1 and K2 for the reactions SCNOH?- SCN? + OH- and SCN? + SCN- ? (SCN)2?-, respectively, were found to decrease with temperature. Due to the considerable decrease of K2 with temperature, a rise in temperature shifts the reaction in favor of SCN?, so the observed yield of (SCN)2?- at high temperatures is strongly dependent on the SCN- concentration. As the SCN? concentration could be as high as or even higher than the (SCN)2?- concentration at high temperatures, a pseudo-first-order decay of SCN? has to be taken into consideration to account for the overall decay of (SCN)2?-. Using the kinetic parameters obtained in this work and available in the literature, the decay profiles of (SCN)2?- can be well reproduced for any temperature and KSCN concentration considered. A combination of the simulation and the experimental results reveals a decrease of ∈max of (SCN)2?- with temperature; the degree is ～30percent for a rise from 25 to 400°C.
Photoredox chemistry in the synthesis of 2-aminoazoles implicated in prebiotic nucleic acid synthesis
Liu, Ziwei,Wu, Long-Fei,Bond, Andrew D.,Sutherland, John D.
, p. 13563 - 13566 (2020)
Prebiotically plausible ferrocyanide-ferricyanide photoredox cycling oxidatively converts thiourea to cyanamide, whilst HCN is reductively homologated to intermediates which either react directly with the cyanamide giving 2-aminoazoles, or have the potential to do so upon loss of HCN from the system. Thiourea itself is produced by heating ammonium thiocyanate, a product of the reaction of HCN and hydrogen sulfide under UV irradiation. This journal is
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 (2011)
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.
Oxidation of Thiocyanate and Iodide Ions by Hydrogen Atoms in Acid Solutions. A pulse Radiolysis Study
Elliot, A. John,Geertsen, Susanne,Buxton, George V.
, p. 1101 - 1112 (1988)
The kinetics and mechanism of the oxidation of SCN- and I- by H atoms in acidic aqueous solution have been studied using pulse radiolysis by following the formation of (SCN)2.- and I2.-.The formation of HSCN.- has been observed as a precursor of (SCN)2.-; it has λmax = 420 nm and εmax = 4.2 x 102 m2 mol-1 and its formation rate constant k(H+SCN-) = (2.3 +/- 0.1) x 108 dm3 mol-1 s-1.Kinetic measurements are consistent with the following mechanism: where R = reduction products.With SCN- R included volatile -SH compounds (probably H2S) but not H2, and with I- R = H2.For X- = SCN-, K = 0.81 +/- 0.08 dm3 mol-1, k1 = 3.0 x 105 and k2 = 2.8 x 106 dm3 mol-1 s-1; and for X- = I-, K = 0.82 +/- 0.13 dm3 mol-1, k1 5 and k2 = (2.3 +/- 0.4) x 107 dm3 mol-1 s-1.The spectrum of HI.- could not be detected.HSCN.- reacts rapidly with O2 with a rate constant of (7.6 +/- 0.6) x 108 dm3 mol-1 s-1, but H(SCN)2.2- appears to be unreactive.No evidence for oxidation of Br- and Cl- by H could be detected.
Substitution kinetics of the aqua ligand in [Re(NO)(H2O)(CN)4]2- by the monodentate nucleophiles SCN-, N3- and thiourea and the X-ray crystal structure of (AsPh4)2[Re(NO)(SC(NH2)2)(CN) 4]
Smith, John,Purcell, Walter,Lamprecht, Gert J.,Roodt, Andreas
, p. 1389 - 1395 (1996)
The substitution reactions between [Re(NO)(H2O)(CN)4]2- and the nucleophiles SCN-, N3- and thiourea revealed that both the aqua and the hydroxo ligands are substituted with respective rate constants of 3.6(1) × 10-3 and 1.57(5) × 10-3 M-1 s-1 at 40°C in the case of SCN-. The pKa1 was spectrophotometrically determined as 9.90(2) at 25°C and kinetically as 9.50(4) at 40°C with NCS- as the incoming nucleophile. The (AsPh4)2[Re(NO)(SC(NH2)2)(CN) 4] complex was isolated as the product for the reaction between [Re(NO)(H2O)(CN)4]2- and thiourea and its X-ray crystal structure determined. The Re - NO and N - O bond lengths are 1.736(11) and 1.146(13) A, respectively, while the Re - S bond distance is 2.503(4) A. The thiourea is bonded cis with respect to the nitrosyl group.
Photoelectron spectroscopy of CN-, NCO-, and NCS-
Bradforth, Stephen E.,Kim, Eun Ha,Arnold, Don W.,Neumark, Daniel M.
, p. 800 - 810 (1993)
The 266 nm photoelectron spectra of CN-, NCO-, and NCS- have been recorded with a pulsed time-of-flight photoelectron spectrometer.The photoelectron spectrum of CN- has also been recorded at 213 nm revealing transitions to the A 2Π state as well as the ground X 2Σ+ state of the CN radical.The following adiabatic electron affinities (EAs) are determined: EA(CN)=3.862+/-0.004 eV, EA(NCO)=3.609+/-0.005 eV, and EA(NCS)=3.537+/-0.005 eV.The adiabatic electron affinity of cyanide is in disagreement with the currently accepted literature value.Our measurement of the electron affinity of NCS confirms recent theoretical estimates that dispute the literature experimental value.By Franck-Condon analysis of the vibrational progressions observed in each spectrum, the change in bond lengths between anion and neutral are also determined.For NCO- this yields R0(C-N)=1.17+/-0.01 Angstroem and R0(C-O)=1.26+/-0.01 Angstroem, and for CN- the equilibrium bond length is found to be Re(C-N)=1.177+/-0.004 Angstroem.The gas phase fundamental for CN- is determined for the first time: ν=2035+/-40 cm-1.
Synthesis and Structure of Nitride-Bridged Uranium(III) Complexes
Chatelain, Lucile,Scopelliti, Rosario,Mazzanti, Marinella
, p. 1784 - 1787 (2016)
The reduction of the nitride-bridged diuranium(IV) complex Cs[{U(OSi(OtBu)3)3}2(-N)] affords the first example of a uranium nitride complex containing uranium in the +III oxidation state. Two nitride-bridged complexes containing the heterometallic fragments Cs2[UIII?-N?-UIV] and Cs3[UIII?-N?-UIII] have been crystallographically characterized. The presence of two or three Cs+ cations binding the nitride group is key for the isolation of these complexes. In spite of the fact that the nitride group is multiply bound to two uranium and two or three Cs+ cations, these complexes transfer the nitride group to CS2 to afford SCN- and uranium(IV) disulfide.
