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Wang Y, Zhao W, Chen X, Ji Y, Zhu X, Chen X, Mei D, Shi H, Lercher JA. Methane-H 2S Reforming Catalyzed by Carbon and Metal Sulfide Stabilized Sulfur Dimers. J Am Chem Soc 2024; 146:8630-8640. [PMID: 38488522 PMCID: PMC10979457 DOI: 10.1021/jacs.4c00738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 03/02/2024] [Accepted: 03/05/2024] [Indexed: 03/28/2024]
Abstract
H2S reforming of methane (HRM) provides a potential strategy to directly utilize sour natural gas for the production of COx-free H2 and sulfur chemicals. Several carbon allotropes were found to be active and selective for HRM, while the additional presence of transition metals led to further rate enhancements and outstanding stability (e.g., Ru supported on carbon black). Most metals are transformed to sulfides, but the carbon supports prevent sintering under the harsh reaction conditions. Supported by theoretical calculations, kinetic and isotopic investigations with representative catalysts showed that H2S decomposition and the recombination of surface H atoms are quasi-equilibrated, while the first C-H bond scission is the kinetically relevant step. Theory and experiments jointly establish that dynamically formed surface sulfur dimers are responsible for methane activation and catalytic turnovers on sulfide and carbon surfaces that are otherwise inert without reaction-derived active sites.
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Affiliation(s)
- Yong Wang
- Department
of Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstrasse 4, 85748 Garching, Germany
- School
of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P. R. China
| | - Wenru Zhao
- School
of Materials Science and Engineering, Tiangong
University, Tianjin 300387, P. R. China
| | - Xiaofeng Chen
- Department
of Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstrasse 4, 85748 Garching, Germany
| | - Yinjie Ji
- Department
of Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstrasse 4, 85748 Garching, Germany
- Institute
for Integrated Catalysis, Pacific Northwest
National Laboratory, P.O. Box 999, Richland, Washington 99352, United States
| | - Xilei Zhu
- Department
of Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstrasse 4, 85748 Garching, Germany
| | - Xiaomai Chen
- Department
of Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstrasse 4, 85748 Garching, Germany
| | - Donghai Mei
- School
of Materials Science and Engineering, Tiangong
University, Tianjin 300387, P. R. China
| | - Hui Shi
- School
of Chemistry and Chemical Engineering, Yangzhou
University, Yangzhou 225002, P. R. China
| | - Johannes A. Lercher
- Department
of Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstrasse 4, 85748 Garching, Germany
- Institute
for Integrated Catalysis, Pacific Northwest
National Laboratory, P.O. Box 999, Richland, Washington 99352, United States
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Glöckler E, Kapp L, Wölper C, Schumacher M, Gröschel AH, Schulz S. Homoleptic and heteroleptic ketodiiminate zinc complexes for the ROP of cyclic l-lactide. RSC Adv 2023; 13:29879-29885. [PMID: 37842672 PMCID: PMC10568404 DOI: 10.1039/d3ra06529d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 10/04/2023] [Indexed: 10/17/2023] Open
Abstract
Homo- and heteroleptic ketodiiminate zinc complexes L12Zn2 (1, L1 = [Me2NC2H4NC(Me)CH]2CO), L2(ZnCp)2 (2, L2 = [Me2NC3H6NC(Me)CH]2CO, Cp = C5H5) and L2HZnCp* (3, Cp* = C5Me5) were synthesized and characterized by 1H and 13C NMR and IR spectroscopy as well as by elemental analysis and single crystal X-ray diffraction (sc-XRD, 2, 3). The catalytical activity of heteroleptic complexes 2 and 3 were tested in the ring-opening polymerization (ROP) of l-lactide. Homobimetallic complex 2 showed the highest activity and selectivity for the synthesis of cyclic polylactide (cPLLA; TOF = 17 460 h-1) at 100 °C in toluene solution, while linear polymers are formed with mononuclear complex 3.
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Affiliation(s)
- Eduard Glöckler
- Faculty of Chemistry, University of Duisburg-Essen Universitätsstraße 7 45141 Essen Germany
| | - Leon Kapp
- Faculty of Chemistry, University of Duisburg-Essen Universitätsstraße 7 45141 Essen Germany
| | - Christoph Wölper
- Faculty of Chemistry, University of Duisburg-Essen Universitätsstraße 7 45141 Essen Germany
| | - Marcel Schumacher
- Faculty of Chemistry, University of Münster and Center for Soft Nanoscience (SoN) Busso-Peus-Strasse 10 48149 Münster Germany
| | - André H Gröschel
- Faculty of Chemistry, University of Münster and Center for Soft Nanoscience (SoN) Busso-Peus-Strasse 10 48149 Münster Germany
| | - Stephan Schulz
- Faculty of Chemistry, University of Duisburg-Essen Universitätsstraße 7 45141 Essen Germany
- Center for Nanointegration Duisburg-Essen (CENIDE) Carl-Benz-Straße 199 47057 Duisburg Germany
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3
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Radhika S, Chandravarkar A, Anilkumar G. Cu(ii)-catalyzed C-N coupling of 2-aminobenzothiazoles with boronic acids at room temperature. RSC Adv 2023; 13:17188-17193. [PMID: 37304782 PMCID: PMC10248544 DOI: 10.1039/d3ra02979d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 05/31/2023] [Indexed: 06/13/2023] Open
Abstract
A Cu(ii)-catalyzed, effective C-N coupling of 2-aminobenzothiazoles with boronic acids in acetonitrile under open vessel chemistry was achieved. This protocol demonstrates the N-arylation of 2-aminobenzothiazoles with a broad range of differently substituted phenylboronic acids at room temperature and accomplishes moderate to excellent yields of the desired products. Under the optimized condition, phenylboronic acids bearing halogen at the para and meta positions were found to be more fruitful.
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Affiliation(s)
- Sankaran Radhika
- School of Chemical Sciences, Mahatma Gandhi University P D Hills P O Kottayam Kerala India 686560
| | - Aravind Chandravarkar
- School of Chemical Sciences, Mahatma Gandhi University P D Hills P O Kottayam Kerala India 686560
| | - Gopinathan Anilkumar
- School of Chemical Sciences, Mahatma Gandhi University P D Hills P O Kottayam Kerala India 686560
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Wiesner T, Heurix M, Fischer RC, Torvisco A, Haas M. Synthesis and Characterization of a Variety of α,ω-Bisacylpolysilanes-A Study on Reactivity and Accessibility. ACS Omega 2022; 7:38025-38036. [PMID: 36312430 PMCID: PMC9609067 DOI: 10.1021/acsomega.2c05258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 09/27/2022] [Indexed: 06/16/2023]
Abstract
In this study, a variety of α,ω-bisacylpolysilanes were synthesized via two synthetic protocols. The first method for obtaining these compounds is based on the substitution reaction of bromine either on silica gel or by the use of silver salts. Surprisingly, instead of the expected bromine substitution product PhC(O)(SiMe2)2C(O)Ph 4a, we found the formation of the diastereomer PhC(O)(SiMe2)2CBrPhOCBrPh(SiMe2)2C(O)Ph 4b indicating a more complex reaction cascade. On the other hand, the phenylated compound 3b yielded the expected bromine substitution product PhC(O)(SiPh2)2C(O)Ph 4c. For the second protocol, we utilized the Corey-Seebach approach to isolate other representatives of this compound class. We found that the substituents at the α-silicon atoms influence the selectivity of the dethioketalization. While the ethylated and phenylated disilanes 5b,c yield the expected bisacyldisilanes 6a,b, the methylated disilane 4a undergoes a BF3-induced Si-Si bond breakage followed by an intermolecular sila-aldol reaction. This hitherto unknown sila-aldol reaction results in the formation of the enantiomer PhC(O)SiMe2C(OMe)PhSiMe2F 6c in excellent yields. All isolated compounds were analyzed by a combination of NMR spectroscopy, ultraviolet-visible (UV-vis) spectroscopy, single-crystal X-ray crystallography, and mass spectrometry. Furthermore, the photochemical pathways of two representative examples (4b,c) were examined.
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Zeitz JO, Ehbrecht T, Fleischmann A, Most E, Gessner DK, Friedrichs S, Sparenberg M, Failing K, Whelan R, Lütjohann D, Eder K. Effect of DL-Methionine Supplementation on Tissue and Plasma Antioxidant Status and Concentrations of Oxidation Products of Cholesterol and Phytosterols in Heat-Processed Thigh Muscle of Broilers. Animals (Basel) 2020; 10:E2050. [PMID: 33167600 PMCID: PMC7694460 DOI: 10.3390/ani10112050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 10/29/2020] [Accepted: 11/03/2020] [Indexed: 12/22/2022] Open
Abstract
In this study, the hypothesis that supplementation with methionine (Met) as DL-Met (DLM) in excess of the National Research Council (NRC) recommendations improves the antioxidant system in broilers was investigated. Day-old male Cobb-500 broilers (n = 72) were divided into three groups which were fed a control diet or diets supplemented with two levels of DLM in which the concentrations of Met + Cys exceeded the recommendations of NRC by 15-20% (group DLM 1) or 30-40% (group DLM 2), respectively. The three groups of broilers did not show differences in body weight gains, feed intake, and feed conversion ratio. However, broilers of groups DLM 1 and DLM 2 had higher concentrations of glutathione (GSH) in liver and thigh muscle and lower concentrations of cholesterol oxidation products (COPs) in heat-processed thigh muscle than broilers of the control group. Concentrations of several oxidation products of phytosterols in heat-processed thigh muscle were also reduced in groups DLM 1 and DLM 2; however, the concentration of total oxidation products of phytosterols was not different between the three groups. The study shows that DLM supplementation improved the antioxidant status due to an increased formation of GSH and reduced the formation of COPs during heat-processing in thigh muscle.
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Affiliation(s)
- Johanna O. Zeitz
- Institute of Animal Nutrition and Nutritional Physiology, Justus Liebig University, D-35392 Giessen, Germany; (J.O.Z.); (T.E.); (A.F.); (E.M.); (D.K.G.)
| | - Tamara Ehbrecht
- Institute of Animal Nutrition and Nutritional Physiology, Justus Liebig University, D-35392 Giessen, Germany; (J.O.Z.); (T.E.); (A.F.); (E.M.); (D.K.G.)
| | - Anne Fleischmann
- Institute of Animal Nutrition and Nutritional Physiology, Justus Liebig University, D-35392 Giessen, Germany; (J.O.Z.); (T.E.); (A.F.); (E.M.); (D.K.G.)
| | - Erika Most
- Institute of Animal Nutrition and Nutritional Physiology, Justus Liebig University, D-35392 Giessen, Germany; (J.O.Z.); (T.E.); (A.F.); (E.M.); (D.K.G.)
| | - Denise K. Gessner
- Institute of Animal Nutrition and Nutritional Physiology, Justus Liebig University, D-35392 Giessen, Germany; (J.O.Z.); (T.E.); (A.F.); (E.M.); (D.K.G.)
| | - Silvia Friedrichs
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, D-53127 Bonn, Germany; (S.F.); (D.L.)
| | - Marion Sparenberg
- Unit of Biomathematics and Data Processing, Faculty of Veterinary Medicine, Justus Liebig University, D-35392 Giessen, Germany; (M.S.); (K.F.)
| | - Klaus Failing
- Unit of Biomathematics and Data Processing, Faculty of Veterinary Medicine, Justus Liebig University, D-35392 Giessen, Germany; (M.S.); (K.F.)
| | - Rose Whelan
- Evonik Operations GmbH, D-63457 Hanau-Wolfgang, Germany;
| | - Dieter Lütjohann
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, D-53127 Bonn, Germany; (S.F.); (D.L.)
| | - Klaus Eder
- Institute of Animal Nutrition and Nutritional Physiology, Justus Liebig University, D-35392 Giessen, Germany; (J.O.Z.); (T.E.); (A.F.); (E.M.); (D.K.G.)
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