505-14-6Relevant articles and documents
Kinetic study on hydrolysis and oxidation of formamidine disulfide in acidic solutions
Hu, Ying,Feng, Jiamin,Li, Yanwei,Sun, Yanyan,Xu, Li,Zhao, Yuemin,Gao, Qingyu
experimental part, p. 235 - 241 (2012/03/22)
Hydrolysis and oxidation of formamidine disulfide in acidic medium were investigated using high-performance liquid chromatography (HPLC) and mass spectrometry (MS) at 25 °C. By controlling the slow reaction rate and choosing appropriate mobile phase, HPLC provides the unique advantages over other methods (UV-Vis, chemical separation) in species tracking and kinetic study. In addition to thiourea and formamidine sulfinic acid, two unreported products were also detected in the hydrolysis reaction. Mass spectrometry measurement indicates these two products to be formamidine sulfenic acid and thiocyanogen with mass weights of 92.28 and 116.36, respectively. In the oxidation of formamidine disulfide by hydrogen peroxide, besides thiourea, formamidine sulfenic acid, formamidine sulfinic acid, thiocyanogen and urea, formamidine sulfonic acid and sulfate could be detected. The oxidation reaction was found to be first order in both formamidine disulfide and hydrogen peroxide. The rate constants of hydrolysis and oxidation reactions were determined in the pH range of 1.5-3.0. It was found both rate constants are increased with the increasing of pH. Experimental curves of different species can be effectively simulated via a mechanism scheme for formamidine disulfide oxidation, including hydrolysis equilibrium of formamidine disulfide and irreversible hydrolysis of formamidine sulfenic acid.
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 (2007/10/03)
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.
THE INFRARED SPECTRA OF THE HALOGEN ISOCYANATE AND THIOCYANATE VAPOR MOLECULES
Devore, T. C.
, p. 287 - 304 (2007/10/02)
Fourier transform infrared spectroscopy has been used to investigate the IR spectra of the XNCO (X = Cl, Br, I, CN), the XSCN (X = Cl, Br, I) and the NCNCS vapor molecules from 4800 to 400 cm-1.Vibrational frequencies have been determined for e