Article
Chemistry, Physical
Yeong Bum Kim, Dongwook Kim, Shashikant U. Dighe, Sukbok Chang, Jung-Woo Park
Summary: This research describes a novel cobalt-catalyzed reaction for the synthesis of terminal branched allylsilanes under mild conditions. Mechanistic studies show the key intermediate and the order of bond migration involved in the process.
Article
Chemistry, Physical
Manoj Kumar Sahoo, Dongwook Kim, Sukbok Chang, Jung-Woo Park
Summary: This study demonstrates the regioselective migratory hydrofunctionalization of alkynes to produce alpha-vinylsilanes and alpha-vinylgermanes using a cobalt hydride based system. The mechanism of alkyne pi-bond migration by the cobalt hydride species is supported by both experimental and computational studies, which elucidates the unique alpha-vinyl selectivity.
Article
Engineering, Environmental
Yi Zhang, Fangyu Guo, Keke Wang, Jun Di, Bokki Min, Huiyuan Zhu, Hailong Chen, Yu-Xiang Weng, Jiayu Dai, Yuanbin She, Jiexiang Xia, Huaming Li
Summary: Insufficient charge separation and feeble CO2 activation can be improved by constructing organic-inorganic hybrid composites. The defect-induced interfacial Bi-O bridge bond accelerates the electron extraction and transfer, while the optimized active sites, Co atoms, enhance CO2 adsorption and activation. The CO2 photoreduction efficiency is increased significantly in the presence of 0.5% Co-TCPP/Bi3O4Br.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Inorganic & Nuclear
Yufang Xie, Qiyi Miao, Wenhao Deng, Yilei Lu, Yinuo Yang, Xiaohui Chen, Rong-Zhen Liao, Shengfa Ye, Chen-Ho Tung, Wenguang Wang
Summary: A diamido-bridged dicobalt complex supported by a diamidonaphthalene ligand, Cp*Co2(2)(mu-1,8-C10H8(NH)(2)) (1), was synthesized and its reactivity towards redox transformations of the Co2N2 core was investigated. It was found that the Co(II)-Co(II) bond can be protonated, resulting in the formation of a bridging hydride [1H](+). The diamidonaphthalene ligand stabilizes the Co(II)Co(III) mixed-valent state (1(+)), which can bind CO to form [1-CO](+). Surprisingly, the mixed-valent complex also activates H2O to give a Co(III)Co(III) hydroxy complex [1-OH](+), accompanied by the release of H2.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Renjie Liu, Denis Leshchev, Eli Stavitski, Mitchell Juneau, Jane N. Agwara, Marc D. Porosoff
Summary: Research on utilizing CO2 as a C-1 feedstock for the synthesis of chemicals and fuels shows that the selectivity of catalysts is strongly linked to the Si/Al ratio and the method of introducing the K promoter.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Chemistry, Inorganic & Nuclear
Maxim A. Faraonov, Alexey V. Kuzmin, Salavat S. Khasanov, Alexander F. Shestakov, Akihiro Otsuka, Hideki Yamochi, Hiroshi Kitagawa, Dmitri V. Konarev
Summary: The synthesis of the first negatively charged iron-bridged fullerene C-60 dimer is reported, and its structure and spectra are analyzed. The bridged iron atoms are coordinated to the C-60 cages, forming a dimer with a singlet ground state.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Wenhui Li, Xiaowa Nie, Hong Yang, Xiang Wang, Felipe Polo-Garzon, Zili Wu, Jie Zhu, Jianyang Wang, Yi Liu, Chuan Shi, Chunshan Song, Xinwen Guo
Summary: Efficient conversion of CO2 is essential for sustainable production of chemicals and fuels. This study reveals the crystallographic dependence of reaction pathways for CO2 hydrogenation on cobalt catalysts, providing insights for the rational design of selective catalysts for CO2 conversion.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2022)
Article
Chemistry, Physical
Sana Ullah, Emma C. Lovell, Tze Hao Tan, Bingqiao Xie, Priyank Kumar, Rose Amal, Jason Scott
Summary: The study showed that illuminating the Co10/Lax-TiO2 catalyst with visible light can enhance the efficiency of CO2 methanation reaction, especially with lanthanum (La) doping, which significantly lowers the activation energy and improves CO2 conversion.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Chemistry, Inorganic & Nuclear
Asmaa Yousofvand, Mojtaba Amini, Mojtaba Hosseinifard, Jan Janczak
Summary: A new polyoxomolybdate compound was synthesized, characterized, and used as a catalyst for the azide-alkyne cycloaddition reaction with high yields. The compound consists of [Co(H2O)6]2+ and N-methyluroptropine cations, a polyanion [C6H12N2CoMo6O24]4-, and lattice water molecules.
Article
Chemistry, Physical
Yinwu Li, Peifeng Su, Jingxing Jiang, Zhuofeng Ke
Summary: The study focuses on the catalytic mechanism of the Zr/Co complex in H-2 activation and hydrogenation, revealing the stabilization of the Lewis acidic Zr center by the Zr Co triple bond, and the promotion of bridging hydride bond formation through breaking the Zr Co triple bond. Reactivity and conjugated effects play crucial roles in subsequent hydrogenation, while E/Z selectivity is influenced by the steric hindrance of the Pr group. The design of catalysts with divergent E/Z selectivity is based on the understanding of the bifunctional mode of the heterobimetallic multiple bond.
Article
Chemistry, Multidisciplinary
Xinning Song, Weiwei Guo, Xiaodong Ma, Liang Xu, Xingxing Tan, Limin Wu, Shunhan Jia, Tianbin Wu, Jun Ma, Farao Zhang, Jinchao Jia, Xiaofu Sun, Buxing Han
Summary: Co nanoparticles supported on N,B-co-doped graphitic carbon exhibited efficient electrocatalytic activity towards CO2 transformation to CO, with a high current density and faradaic efficiency. The CO to H2 ratio can be adjusted by changing the amount of B doping. The excellent performance of the catalyst is attributed to its favorable electron density configuration, larger electrochemical surface area, and higher conductivity.
Article
Energy & Fuels
Shoji Iguchi, Siyuan Jia, Yuji Ogishima, Yuki Senba, Hitoshi Ogihara, Ichiro Yamanaka
Summary: A new compound Co(PV4Py)/KB(673 K) prepared by partial pyrolysis showed efficient catalytic activity for the electro-reduction of CO2 to CO in a solid polymer electrolyte (SPE) electrolysis gas cell without the use of carbonate solutions.
Article
Chemistry, Physical
Nazmul Hasan Md Dostagir, Rattanawalee Rattanawan, Min Gao, Jin Ota, Jun-ya Hasegawa, Kiyotaka Asakura, Atsushi Fukouka, Abhijit Shrotri
Summary: The study presents a catalyst with isolated Co atoms in ZrO2 that enhances CO selectivity during CO2 hydrogenation by utilizing oxygen vacant sites. The synergy between Co and Zr is crucial for generating oxygen vacancies and stabilizing formate intermediates, leading to the control of product selectivity in CO2 hydrogenation reactions.
Article
Chemistry, Physical
Chao Zhang, Jiwon Yang, Keisuke Hara, Rento Ishii, Hongwei Zhang, Takaomi Itoi, Yasuo Izumi
Summary: Porphyrin and its derivatives combined with first-row transition metals have been widely used for electrochemical and photocatalytic applications. Co-TCPP anchored on TiO2 showed high photoactivity for CO production under UV-visible light irradiation. The photoactivity drop could be solved by removing hydroxy ligands through ethanol treatment, leading to an increased CO photoformation rate.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Physical
Pauline Bredy, David Farrusseng, Yves Schuurman, Frederic C. Meunier
Summary: An operando IR study reveals that the decline in selectivity to higher hydrocarbons over cobalt-based Fischer-Tropsch catalysts when CO is replaced with CO2 is mainly attributed to surface coverage effects.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Qi Zhang, Stefano Crespi, Ryojun Toyoda, Romain Costil, Wesley R. Browne, Da-Hui Qu, He Tian, Ben L. Feringa
Summary: By utilizing hydrogen bonds, control over the chirality of disulfide bonds is achieved to enable intramolecular and supramolecular chirality transfers, showcasing the accessibility of dynamic stereochemical space through noncovalent chirality transmission encoded in homochiral amino acid building blocks.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Linda E. Eijsink, Andy S. Sardjan, Esther G. Sinnema, Hugo den Besten, Keimpe J. van den Berg, Jitte Flapper, Rogier van Gemert, Ben L. Feringa, Wesley R. Browne
Summary: The curing process of bis-methacrylate-styrene resins was monitored using EPR and Raman spectroscopy. The results show the appearance and persistence of methacrylate and polystyrene radical species during the polymerization. Temperature and conversion rate also impact the radical signals.
Article
Chemistry, Physical
Jorn D. Steen, Anouk Volker, Daniel R. Duijnstee, Andy S. Sardjan, Wesley R. Browne
Summary: This study reveals that potential-induced changes in the SERS spectra of self-assembled monolayers of thiophenol on roughened gold surfaces can be attributed to local changes in pH at the electrode. The pH at the electrode can undergo significant changes during electrochemical measurements and takes considerable time to recover to the pH of the bulk solution.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Johann B. B. Kasper, Pattama Saisaha, Maurits de Roo, Mitchell J. J. Groen, Laia Vicens, Margarida Borrell, Johannes W. W. de Boer, Ronald Hage, Miquel Costas, Wesley R. R. Browne
Summary: This study elucidates the mechanism and reactive species involved in the oxidation of alkenes and alcohols with H2O2 under the presence of a specific catalyst. The findings suggest that a certain reactive species can engage in both alkene and alcohol oxidation reactions, exhibiting selectivity.
Review
Chemistry, Physical
Jorn D. Steen, Daniel R. Duijnstee, Wesley R. Browne
Summary: Molecular switching has become a key functionality in addressable materials and surfaces. However, the wide variation in interfaces studied, from single-molecule devices to two-dimensional self-assembled monolayers and thin films, poses challenges in their use and characterization. The low number density of molecules on modified interfaces and the complexity of characterizing molecular function further complicate the analysis. This review discusses the techniques and approaches used for characterizing molecular switches applied to interfaces and emphasizes the importance of understanding the limitations and quirks of specific techniques through the use of model compounds.
SURFACE SCIENCE REPORTS
(2023)
Article
Multidisciplinary Sciences
Palas Roy, Wesley R. Browne, Ben L. Feringa, Stephen R. Meech
Summary: Controlling molecular translation at the nanoscale is a key objective for development of synthetic molecular machines. Recently developed third generation photochemically driven molecular motors (3GMs) offer the possibility of converting light energy into translational motion. Detailed understanding of their excited state dynamics facilitates the development of 3GMs.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Johann B. Kasper, Laia Vicens, C. Maurits de Roo, Ronald Hage, Miquel Costas, Wesley R. Browne
Summary: Mononuclear MnII oxidation catalysts with aminopyridine-based ligands achieve high TON enantioselective epoxidation of alkenes with H2O2. The electronic effect of peripheral ligand substituents plays a role in the enantioselectivity and maximum TON. The use of low temperatures and slow addition of H2O2 reduces competing H2O2 disproportionation and improves TONs for alkene oxidation.
Article
Chemistry, Multidisciplinary
Palas Roy, Andy S. Sardjan, Wojciech Danowski, Wesley R. Browne, Ben L. Feringa, Stephen R. Meech
Summary: In this study, a novel push-pull overcrowded alkene motor was synthesized and characterized by steady-state and ultrafast time-resolved electronic spectroscopy. It was found that tuning the charge transfer character in the excited state has a significant effect on the photoisomerization yield, providing new routes for precise control of motor efficiency.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
W. J. Niels Klement, Jorn D. Steen, Wesley R. Browne
Summary: Electrochemistry and electrochemical reactions play a crucial role in the transition to a sustainable chemical industry. To understand these reactions, time-, potential-, and spatially resolved analysis is necessary. This study demonstrates the use of surface-enhanced Raman scattering (SERS) and resonance Raman spectroscopy for spatially and time-resolved analysis of solution composition at and near the electrode surface. The results show the potential of this approach in elucidating electro(catalytic) reactions at electrode interfaces. Rating: 7/10
Article
Biochemistry & Molecular Biology
Ross J. Mcgarry, Lazaros Varvarezos, Mary T. Pryce, Conor Long
Summary: The photophysical properties of Cu(II) complexes with different types of porphyrins were studied using experimental and computational methods, revealing the important role of ligand-to-metal charge-transfer states in directing system behavior. The experiments demonstrated that the system can undergo either intersystem crossing or coordinative expansion depending on the presence of Lewis bases. The results also showed that the processes of coordinative expansion and crossing to the triplet hypersurface occur in different time scales and are mutually exclusive.
Article
Chemistry, Multidisciplinary
Harmke S. Siebe, Andy S. Sardjan, Sarina C. Massmann, Jitte Flapper, Keimpe J. van den Berg, Niek N. H. M. Eisink, Arno P. M. Kentgens, Ben L. Feringa, Akshay Kumar, Wesley R. Browne
Summary: Renewable polysaccharide feedstocks are widely used in bio-based food packaging, coatings, and hydrogels. However, their physical properties often require chemical modification, such as oxidation using periodate, to achieve desired characteristics. In this study, gum arabic was found to undergo oxidation primarily in the rhamnose and arabinose subunits, while galacturonic acids were unaffected. The oxidation process resulted in the formation of substituted dioxanes instead of aldehydes, which has implications for crosslinking strategies in the development of renewable polysaccharide-based materials.
Article
Chemistry, Multidisciplinary
Cosima Staehler, Lars Grunenberg, Maxwell W. Terban, Wesley R. Browne, Daniel Doellerer, Michael Kathan, Martin Etter, Bettina Lotsch, Ben L. Feringa, Simon Krause
Summary: The incorporation of molecular machines into porous framework structures has the potential to enhance various functions such as nano actuation and molecular transport. In this study, a light-driven molecular motor was synthesized and integrated into polymers and covalent organic frameworks (COF). The structural and dynamic properties of the resulting solids were analyzed using spectroscopic, diffraction, and theoretical methods. A crystalline 2D COF with stacked hexagonal layers containing 20 mol% molecular motors was successfully synthesized. The COF exhibited high pore volume and surface area. The supramolecular assembly and motor dynamics of the COF layers were also investigated. This research provides important insights for the analysis, design, and synthesis of motorized porous framework materials.
Article
Chemistry, Multidisciplinary
Johan Bootsma, Wesley R. Browne, Jitte Flapper, Bas de Bruin
Summary: In this study, photoactive complexes were found to enable photochemical control over alkyd paint curing without the need for antiskinning agents. This approach provides greater flexibility in the curing process and outperforms commonly used cobalt- and manganese-based catalysts.
Article
Chemistry, Multidisciplinary
Nadja A. Simeth, Paula de Mendoza, Victor R. A. Dubach, Marc C. A. Stuart, Julien W. Smith, Tibor Kudernac, Wesley R. Browne, Ben L. Feringa
Summary: Molecular recognition-driven self-assembly using single-stranded DNA as a template is a promising method to obtain complex structures from simple building blocks. In this study, the beneficial properties of a photoresponsive biohybrid hydrogel were controlled with light, adding an extra level of function to the system. The structural response of the hydrogel at both the microscopic and macroscopic scale was studied, revealing remarkable shape-memory properties and shape manipulation capabilities.
Article
Materials Science, Multidisciplinary
Ruben Feringa, Harmke S. Siebe, W. J. Niels Klement, Jorn D. Steen, Wesley R. Browne
Summary: The study demonstrates that immobilizing photochromic molecular switches in a PMMA polymer matrix allows for tuning of color and transparency. By utilizing the primary inner filter effect and the layered construction of the films, only a single excitation wavelength is required for photochemical switching.
MATERIALS ADVANCES
(2022)
