624-92-0Relevant articles and documents
The prototypical organophosphorus ylidion ·CH2PH3+
Schweighofer, Andreas,Chou, Phillip K.,Thoen, Kami K.,Nanayakkara, Vajira K.,Keck, Helmut,Kuchen, Wilhelm,Kentt?maa, Hilkka I.
, p. 11893 - 11897 (1996)
The reactivity of the prototypical phosphorus-containing ylidion (α-distonic ion) ·CH2PH3+ has been investigated in the gas phase by using a dual cell Fourier-transform ion cyclotron resonance mass spectrometer. The ion ·CH2PH3+ and its more stable conventional isomer CH3PH2·+ show distinctly different reactivities toward neutral reagents. This observation contrasts the facile interconversion of the analogous sulfur- and oxygen-containing distonic ions ·CH2SH2+ and ·CH2OH2+ with their conventional isomers CH3OH·+ and CH3SH·+, respectively, within collision complexes in the gas phase. Bracketing experiments yield a proton affinity of 190.4 ± 3 kcal mol-1 for the phosphorus atom in ·CH2PH2. Together with a calculated heat of formation for ·CH2PH2, this value yields a heat of formation of 217 ± 3 kcal mol-1 (at 298 K) for the distonic ion ·CH2PH3+.
Spectroscopic and Photochemical Properties of CH3SNO
Niki, H.,Maker, P. D.,Savage, C. M.,Breltenbach, L. P.
, p. 7 - 9 (1983)
UV and IR absorption cross sections were measured for methyl thionitrite at 298 K.This compound was found to undergo photochemical reactions in the wavelength region of 300-400 nm via CH3SNO + hν -> CH3S + NO followed by CH3S + NO -> CH3SNO and 2CH3S -> CH3SSCH3.Preliminary results on the mechanism of the reaction of CH3S with O2 were also obtained.
Characteristic flavor formation of thermally processed N-(1-deoxy-α-D-ribulos-1-yl)-glycine: Decisive role of additional amino acids and promotional effect of glyoxal
Zhan, Huan,Cui, Heping,Yu, Junhe,Hayat, Khizar,Wu, Xian,Zhang, Xiaoming,Ho, Chi-Tang
, (2021/09/28)
The role of amino acids and α-dicarbonyls in the flavor formation of Amadori rearrangement product (ARP) during thermal processing was investigated. Comparisons of the volatile compounds and their concentrations when N-(1-deoxy-α-D-ribulos-1-yl)-glycine r
Effect of Zinc Oxide on the Thermal Decomposition of Dimethyl Sulfoxide
Chen, Liping,Chen, Wanghua,Guo, Zichao,Li, Huabo,Weng, Shichun,Wu, Wenqian
, (2022/03/14)
Dimethyl sulfoxide (DMSO) is widely used in the chemical industry. However, it has a non-neglectful thermal runaway risk due to the nature of self-accelerating decomposition near the boiling point. Under the background that zinc oxide (ZnO) may extend the isothermal induction period of thermal decomposition of DMSO, this article conducts an in-depth study for the phenomenon with the techniques such as differential scanning calorimetry (DSC), accelerating rate calorimetry (ARC), gas chromatography-mass spectrometry (GC-MS), X-ray photoelectron spectroscopy (XPS), and X-ray diffractometry (XRD). After being mixed with ZnO, the maximum decomposition rate of DMSO was significantly reduced and the adiabatic induction period of DMSO decomposition was extended by 3.27 times, indicating that the thermal decomposition intensity of DMSO was obviously reduced. It was experimentally demonstrated that ZnO did not change the decomposition pathways of DMSO, but it could promote the decomposition of methanethiol, which was a decomposition intermediate of DMSO and could potentially serve as a promoter on the decomposition of DMSO.
Preoxidation-assisted nitrogen enrichment strategy to decorate porous carbon spheres for catalytic adsorption/oxidation of methyl mercaptan
Fan, Caimei,Kou, Lifang,Li, Rui,Wang, Rongxian,Wang, Yaqi,Zhang, Changming,Zhang, Xiaochao
, p. 37644 - 37656 (2020/11/02)
Porous carbon spheres with high surface area and microporous structure were synthesized from alkyl phenols and formaldehyde via suspension polymerization and steam activation. The effects of air oxidation and ammonia solution heat treatment on the pore structure and surface chemistry of the carbon spheres were studied for catalytic oxidation of CH3SH. The structure property and surface chemistry of the obtained carbon spheres were characterized by N2 adsorption-desorption, FTIR, scanning electron microscopy, XRD, elemental analysis, X-ray photoelectron spectroscopy and Boehm titration, and then thermal analysis and gas chromatography-mass spectrometry were applied to investigate the catalytic oxidation product. Results show that the as-prepared microporous carbon spheres through direct ammonia treatment have a high surface area value of 1710 m2 g-1 and a total pore volume of 0.83 cm3 g-1. Moreover, the preoxidation-assisted nitrogen enrichment strategy not only increases the surface area and total pore volume of the carbon spheres, but also introduces more active nitrogen species such as pyridinic nitrogen and quaternary nitrogen, leading to the highest nitrogen content of 7.13 wt% and the highest CH3SH capacity of 622.8 mg g-1 due to the pyridinic nitrogen and quaternary nitrogen as function of catalysts. In addition, water and oxygen have a beneficial effect on CH3SH oxidation over the nitrogen modified carbon spheres, and the basic oxidation product is CH3SSCH3 that can be further oxidized into CH3SO2SCH3 according to DTG and GC/MS analysis. The great recycling stability after ten cycles with a reserved CH3SH capacity of 97% demonstrates that the porous carbon spheres obtained by preoxidation-assisted enriched nitrogen strategy are promising for catalytic oxidation of CH3SH. This journal is
Application of Ni-based metal-organic framework as heterogeneous catalyst for disulfide addition to acetylene
Ananikov, Valentine P.,Degtyareva, Evgeniya S.,Erokhin, Kirill S.
, (2020/08/05)
Several recent studies have shown unique adsorption activity of metal organic frameworks (MOFs) towards unsaturated hydrocarbons. In the current article, we explored the application of Ni-MOFs for S-functionalization of acetylene. We showed that Ni-MOF-74 catalyzed the reaction of disulfide addition to gaseous acetylene with excellent selectivity. The prime advantage of the proposed Ni-MOF-74 over other examined catalysts was its easy separation and recycling possibility. Moreover, it demonstrated no leaching of Ni species into the solution. The work was supplemented with a study on the catalyst behavior in the course of the reaction by using SEM, EDX, XRD, and FT-IR methods.
Rh-Catalyzed Hydrogenation of CO2 to Formic Acid in DMSO-based Reaction Media: Solved and Unsolved Challenges for Process Development
Jens, Christian M.,Scott, Martin,Liebergesell, Bastian,Westhues, Christian G.,Sch?fer, Pascal,Franciò, Giancarlo,Leonhard, Kai,Leitner, Walter,Bardow, André
supporting information, p. 307 - 316 (2018/11/10)
Process concepts have been conceived and evaluated for the amine-free homogeneous catalyzed hydrogenation of CO2 to formic acid (FA). Base-free DMSO-mediated production of FA has been shown to avoid the formation of stable intermediates and presumably the energy-intensive FA recovery strategies. Here, we address the challenges in the development of an overall process: from catalyst immobilization to the FA isolation. The immobilization of the homogeneous catalyst was achieved using a multiphasic approach (n-heptane/DMSO) ensuring high retention of the catalyst (>99%) and allowing facile separation of the catalyst-free product phase. We show that the strong molecular interactions between DMSO and FA on the one hand shift the equilibrium towards the product side, on the other hand, lead to the formation of an azeotrope preventing a simple isolation step by distillation. Thus, we devised an isolation strategy based on the use of co-solvents and computed the energy demands. Acetic acid was identified as best co-solvent and its compatibility with the catalyst system was experimentally verified. Overall, the outlined process involving DMSO and acetic acid as co-solvent has a computed energy demand on a par with state-of-the art amine-based processes. However, the insufficient chemical stability of DMSO poses major limitations on processes based on this solvent. (Figure presented.).
Dicationic Thiolate-Bridged Diruthenium Complexes for Catalytic Oxidation of Molecular Dihydrogen
Yuki, Masahiro,Sakata, Ken,Nakajima, Kazunari,Kikuchi, Syoma,Sekine, Shinobu,Kawai, Hiroyuki,Nishibayashi, Yoshiaki
supporting information, p. 4499 - 4506 (2017/12/05)
Dicationic thiolate-bridged diruthenium complexes bearing sterically bulky alkane substituents on the thiolate ligands such as [Cp?Ru(μ-SiPr)2Ru(OH2)Cp?](OTf)2 have been found to work as effective catalysts toward oxidation of molecular dihydrogen into protons and electrons in protic solvents such as water and methanol. DFT calculations indicate that the sterically bulky alkane substituent in the complex plays an important role in facilitating the reaction step of the coordination of molecular dihydrogen.
Cytosine Radical Cations: A Gas-Phase Study Combining IRMPD Spectroscopy, UVPD Spectroscopy, Ion–Molecule Reactions, and Theoretical Calculations
Lesslie, Michael,Lawler, John T.,Dang, Andy,Korn, Joseph A.,Bím, Daniel,Steinmetz, Vincent,Ma?tre, Philippe,Ture?ek, Frantisek,Ryzhov, Victor
, p. 1293 - 1301 (2017/05/26)
The radical cation of cytosine (Cyt.+) is generated by dissociative oxidation from a ternary CuII complex in the gas phase. The radical cation is characterized by infrared multiple photon dissociation (IRMPD) spectroscopy in the fingerprint region, UV/Vis photodissociation (UVPD) spectroscopy, ion–molecule reactions, and theoretical calculations (density functional theory and ab initio). The experimental IRMPD spectrum features diagnostic bands for two enol-amino and two keto-amino tautomers of Cyt.+ that are calculated to be among the lowest energy isomers, in agreement with a previous study. Although the UVPD action spectrum can also be matched to a combination of the four lowest energy tautomers, the presence of a nonclassical distonic radical cation cannot be ruled out. Its formation is, however, unlikely due to the high energy of this isomer and the respective ternary CuII complex. Gas-phase ion–molecule reactions showed that Cyt.+ undergoes hydrogen-atom abstraction from 1-propanethiol, radical recombination reactions with nitric oxide, and electron transfer from dimethyl disulfide.
Radical Beckmann Rearrangement and Its Application in the Formal Total Synthesis of Antimalarial Natural Product Isocryptolepine via C-H Activation
Mahajan, Pankaj S.,Humne, Vivek T.,Tanpure, Subhash D.,Mhaske, Santosh B.
supporting information, p. 3450 - 3453 (2016/07/26)
The Beckmann rearrangement of ketoximes, mediated by ammonium persulfate-dimethyl sulfoxide as a reagent, has been achieved under neutral conditions. Based on the radical trapping and 18O-labeling experiments, the transformation follows a mechanism involving a radical pathway. The scope and generality of the developed protocol has been demonstrated by 19 examples. The developed protocol and Pd-catalyzed intramolecular double C-H activation were used as key steps in the formal total synthesis of antimalarial natural product isocryptolepine.
