Article
Chemistry, Multidisciplinary
Louis Monsigny, Anna Kajetanowicz, Karol Grela
Summary: This review discusses a distinct class of ruthenium olefin metathesis catalysts with unsymmetrical N-heterocyclic carbene (uNHC) ligands, highlighting their advantages such as thermodynamic stability, chemical latency, selectivity, and compatibility with green solvents in specialized metathesis transformations. Despite being niche, uNHC complexes have the potential to be implemented in various industrial processes like valorization of Fischer-Tropsch olefin fractions, ethenolysis of renewable products, and modern pharmaceutical production.
Article
Chemistry, Physical
Renat Kadyrov
Summary: An efficient and simple catalytic system has been developed for the hydrogenation of carboxylic esters using commercially available Ru-salts and imidazolium salts. This combination enables the reduction of esters to alcohols at moderate temperature and pressure, offering a practical method for alcohol synthesis.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Physical
Adrian Sytniczuk, Filip Struzik, Vishal Purohit, Karol Grela, Anna Kajetanowicz
Summary: The synthesis of inexpensive 2-isopropyl-6-methylaniline analogues was achieved through the employment of aza-Claisen rearrangement and subsequent reduction of anilines, overcoming the issue of high price and low availability. The obtained aniline derivatives were utilized in the synthesis of lipophilic Hoveyda-Grubbs-type complexes, serving as efficient catalysts in ethenolysis reactions. The complexes with bulky sec-butyl substituent exhibited superior performance compared to the leading catalyst based on 2-isopropyl-6-methylaniline, making them valuable candidates for large-scale industrial production with a TON of up to 192,000.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Haoyu Wang, Haitao Yu, Dong Bai, Dan Yao, Yongjun Han, Yichao Shi, Zhiqun Wang
Summary: A ruthenium olefin metathesis catalyst (C1-H) with a novel NHC ligand tethered by an ethoxy-pyridyl arm was synthesized and compared with its methylated derivative (C1-Me). The study showed profound variations in initiation rate, kinetics, metathesis activity, and decomposition behavior between these two catalysts. The remote torsional strain was found to have a considerable influence on the catalytic activity and decomposition behavior of this ligand class.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Applied
Louis Monsigny, Jakub Piatkowski, Damian Trzybinski, Krzysztof Wozniak, Tomasz Nienaltowski, Anna Kajetanowicz, Karol Grela
Summary: Two new ruthenium complexes, Sil-II and Sil-II', were synthesized and characterized as catalysts for olefin metathesis reactions. Sil-II' showed better stability and productivity compared to Sil-II, and kinetic experiments revealed differences in initiation mechanisms between the two catalysts.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Physical
Peng Ma, Jiaren Zhang, Xiaqian Wu, Jianhui Wang
Summary: Phosphine-free ruthenium benzylidene complexes with imidazole ligands have been reported. These catalysts are effective for high-temperature ring-closing metathesis (RCM) and cross-metathesis (CM) reactions, unlike the commonly used phosphine-containing N-heterocyclic carbene-based ruthenium catalysts which exhibit side reactions. This discovery paves the way for the development of more selective ruthenium metathesis catalysts for reactions requiring harsh conditions.
Article
Chemistry, Applied
Eva Pump, Albert Poater, Naeimeh Bahri-Laleh, Raffaele Credendino, Luigi Serra, Vittorio Scarano, Luigi Cavallo
Summary: This study computationally investigates the origin of chemo-, regio- and stereoselectivity in cross metathesis reactions leading to the desired product. By comparing the relative stabilities of intermediates and products, as well as transition states, the probability for each pathway is linked. The transition states in each reaction play a crucial role in tuning the regio- and stereoselectivity by defining the energy barriers needed to form the final product. The research findings provide valuable insights for understanding the selectivity in new olefin metathesis reactions and a web-server is developed to support future predictive catalysis.
Article
Chemistry, Physical
Antonio Del Vecchio, Jakub Talcik, Sophie Colombel-Rouen, Jan Lorkowski, Melinda R. Serrato, Thierry Roisnel, Nicolas Vanthuyne, Guy Bertrand, Rodolphe Jazzar, Marc Mauduit
Summary: New Blechert-type ruthenium complexes with cyclic(alkyl)(amino)carbene (CAAC) ligands show remarkable thermal stability in solution and excellent catalytic performances in various metathesis reactions. They exhibit high catalytic activity at low loading and can achieve high enantiomeric excess in asymmetric metathesis reactions.
Article
Chemistry, Multidisciplinary
Saif Eddine Cherif, Avisek Ghosh, Saloua Chelli, Isabelle M. Dixon, Jamil Kraiem, Sami Lakhdar
Summary: This work demonstrates a novel approach to obtain the thermodynamically unfavorable Z-isomer in olefin cross-metathesis reactions by combining a classical E-selective catalyst with a readily available photocatalyst. The scope and limitations of this approach are discussed based on computational and experimental mechanistic data.
Article
Chemistry, Inorganic & Nuclear
Sanjit Das, Dinesh Nugegoda, Wenzhi Yao, Fengrui Qu, Matthew T. Figgins, Robert W. Lamb, Charles Edwin Webster, Jared H. Delcamp, Elizabeth T. Papish
Summary: A new method for synthesizing complexes of the type [(CNC)Ru-II(NN)L](n+) has been introduced and a series of six new complexes have been characterized. The study shows that catalysts with benzimidazole derived CNC pincers exhibit better activity in photocatalysis, and a diimine ligand is required for self-sensitized photocatalysis.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Mizuki Seki, Kazuhiro Yoshida
Summary: A new chiral rhodium catalyst was synthesized and fully characterized, showing good catalytic activity and enantioselectivity in asymmetric reactions.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Wen-Hao Li, Jiarui Yang, Hongyu Jing, Jian Zhang, Yu Wang, Jiong Li, Jie Zhao, Dingsheng Wang, Yadong Li
Summary: By designing and synthesizing a single-atomic-site catalyst with strong electronic metal-support interaction effects, researchers achieved highly selective conversion of electronically unbiased alkynes. Through studying reaction mechanisms, they demonstrated the exciting potential of EMSI in regulating regioselectivity in homogeneous catalysis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Inorganic & Nuclear
Anne-Frederique M. Pecharman, Erika M. Roberts, Fedor M. Miloserdov, Victor Varela-Izquierdo, Mary F. Mahon, Michael K. Whittlesey
Summary: The addition of excess ZnMe2 to a mixture of [Ru(PPh3)(3)HCl] and IMes resulted in the formation of a bis-cyclometallated complex [Ru(IMes)(PPh3)(2)] 2 and a mono-cyclometallated Ru-Zn heterobimetallic complex [Ru(IMes)'(PPh3)(2)(ZnMe)] 3. Further reactions of these complexes with H-2, PhSiH3, pinacolborane, and CO were investigated. Compounds 1, 4, 5, and 6 were synthesized and structurally characterized.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Noy B. Nechmad, Victoria Kobernik, Naziha Tarannam, Ravindra Phatake, Or Eivgi, Sebastian Kozuch, N. Gabriel Lemcoff
Summary: A novel catalyst Ru-S-CF3-I was synthesized with distinct activity and selectivity profiles for olefin metathesis reactions. The combination of photoisomerization and photochemical release of chloride ions allows for a wide scope of photoinduced olefin metathesis reactions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
C. David Diaz-Oviedo, Rajat Maji, Benjamin List
Summary: In this study, an enantioselective intermolecular Prins reaction of styrenes and paraformaldehyde was achieved using confined imino-imidodiphosphate (iIDP) Bronsted acid catalysts, leading to the formation of valuable synthetic building blocks, 1,3-dioxanes. The enantioenriched 1,3-dioxanes can be transformed into optically active 1,3-diols, which are important intermediates in organic synthesis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Kanika Aggarwal, Saja Bsoul, John C. Douglin, Songlin Li, Dario R. Dekel, Charles E. Diesendruck
Summary: Metallopolymers, with metal centers assuming ion transport function, show exceptional alkaline stability in AEMFCs, surpassing current quaternary ammonium cations, and provide a scientific base for further advancements in the field.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Electrochemistry
Zi-Ye Xiao, Charles E. Diesendruck, Viatcheslav Freger, Dario R. Dekel
Summary: In this study, ultra-thin polymer films with significant anion conductance were successfully prepared by electropolymerizing homopolymer and copolymer from vinylbenzyltrimethylammonium chloride and divinylbenzene using cyclic voltammetry. The morphologies and film properties of the electropolymerized polymers were analyzed, and high anion conductance of up to 2 mS was observed in the films. This technique shows potential for the development of anion-conducting electrodes for advanced electrochemical devices.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2022)
Article
Chemistry, Inorganic & Nuclear
Kanika Aggarwal, Songlin Li, Elisa Ivry, Dario R. Dekel, Charles E. Diesendruck
Summary: Metallopolymers have potential as anion exchange membranes (AEMs) in fuel cells and water electrolysis applications. By synthesizing metallopolymers and studying the electronic effects of ligands, the relationship between metal-ligand pairs and AEM properties can be understood. Optimizing the design of complexes with correct electronic parameters can advance the development of practical AEMs for alkaline fuel cells and water electrolyzers.
Article
Multidisciplinary Sciences
Deb Kumar Bhowmick, Tapan Kumar Das, Kakali Santra, Amit Kumar Mondal, Francesco Tassinari, Rony Schwarz, Charles E. Diesendruck, Ron Naaman
Summary: We describe the spin polarization-induced chirogenic electropolymerization of achiral 2-vinylpyridine, which forms a layer of enantioenhanced isotactic polymer on the electrode. The chirality of the polymer film formed on the electrode was confirmed by measuring its electron spin polarization properties as a function of its thickness. Two methods were used: spin polarization measurement by magnetic contact atomic force microscopy and assessment of magnetoresistance in a sandwich-like four-point contact structure. High spin-selective electron transmission was observed, even for a layer thickness of 120 nm. The change in circular dichroism signal correlated with the change in spin polarization as a function of thickness, and the spin-filtering efficiency increased with temperature.
Article
Chemistry, Multidisciplinary
Hang Zhang, Charles E. Diesendruck
Summary: This study found that mechanochemical reactions in block copolymers (BCPs) may have unexpected consequences when subjected to mechanical stress. The activation of mechanophores is accelerated even when they are located at the chain ends, indicating a significant mechanochemical response throughout the polymer chain, even in regions far from the center.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Noy B. Nechmad, Keren Iudanov, Naziha Tarannam, Victoria Kobernik, Sebastian Kozuch, N. Gabriel Lemcoff
Summary: The ruthenium alkylidene-catalyzed ring-closing metathesis (RCM) of 5-membered rings is highly favored due to entropic and enthalpic contributions. However, the RCM of a hindered diene could only be achieved at high concentrations using a trifluoromethyl sulfur-chelated ruthenium benzylidene catalyst. The addition of ethyl acetate significantly enhanced the catalyst's activity.
Article
Chemistry, Multidisciplinary
Nir Lemcoff, Noy B. Nechmad, Or Eivgi, Elad Yehezkel, Ofir Shelonchik, Ravindra S. Phatake, Doron Yesodi, Anna Vaisman, Aritra Biswas, N. Gabriel Lemcoff, Yossi Weizmann
Summary: Light-induced catalysis and thermoplasmonics offer innovative opportunities for research. This study presents the activation of latent ruthenium-based olefin metathesis catalysts using plasmonic gold nanobipyramids. The tunable localized surface plasmon resonance bands of the gold nanobipyramids allowed initiation of catalysts with low-energy visible and infrared light, leading to the formation of plasmonic polymer composites with exceptional properties. The method of catalyst activation through photothermal response proved to be more efficient than conventional heating methods.
Article
Chemistry, Physical
Nebal Alassad, Noy B. Nechmad, Ravindra S. Phatake, Ofer Reany, N. Gabriel Lemcoff
Summary: In this study, the structure, latency, and activity of twelve sulfur-chelated ruthenium precatalysts were investigated by varying their ligand shell. The results revealed that different ligand shells and activation stimuli significantly influenced the catalytic efficiency for different substrate types. In addition, light irradiation was found to promote cis/trans or trans/cis-dihalo isomerization, but did not activate otherwise inactive catalysts.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Inorganic & Nuclear
Gal Segalovich-Gerendash, Mark Baranov, N. Gabriel Lemcoff, Ravindra S. Phatake
Summary: This study describes the synthesis, characterization, and catalytic properties of four new cis-dichlorido ruthenium dithioacetal-chelated complexes. The X-ray structures of the complexes confirm their cis-dichloro configurations, similar to sulfur-chelated benzylidenes. Systematic investigation on the catalytic activity of these complexes for RCM and ROMP reactions provides insights into the impact of dithioacetal chelation on latency and activation behavior.
Article
Chemistry, Physical
Naziha Tarannam, Nebal Alassad, N. Gabriel Lemcoff, Sebastian Kozuch
Summary: A layered meta-benchmarking analysis was conducted to demonstrate a protocol for method selection and estimation of Gibbs energies of catalytically prominent reactions. The study focused on the active-latent equilibrium of two metathesis catalysts and utilized a computational benchmark for gas phase energies, followed by benchmarking enthalpy and Gibbs energy from experimental references. The results indicated the effectiveness of certain reference methods, the accuracy of specific functionals, and the importance of solvation models and entropy in the estimation of Gibbs energy.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
News Item
Chemistry, Multidisciplinary
Charles E. Diesendruck
Summary: Scientists have long studied how polymers break in solutions, but understanding how chains stretch to the point of breaking covalent bonds has proven to be challenging. However, a recent set of experiments strongly support a dynamic model suggesting that chains uncoil from the ends to the middle while simultaneously relaxing.
Article
Engineering, Environmental
Zohar Sahray, Amit N. Shocron, Rana Uwayid, Charles E. Diesendruck, Matthew E. Suss
Summary: Capacitive deionization (CDI) is an emerging technology used for brackish water desalination and ion selective separations. A one-dimensional transient CDI model was used to study the mechanisms enabling monovalent-selective separations. It was discovered that an asymmetric CDI cell with a chemically functionalized cathode induces electric charges in the pristine anode, leading to monovalent cation selectivity. The study also uncovered a novel operational regime called capacitive ion exchange for resin-less exchange of monovalent cations for divalent cations.
Article
Chemistry, Physical
Nebal Alassad, Ravindra S. Phatake, Mark Baranov, Ofer Reany, N. Gabriel Lemcoff
Summary: Cis-dichloro benzylidene phosphite complexes act as latent catalysts at low temperature and are suitable for olefin metathesis reactions and efficient 3-D printing applications. Furthermore, combining them with plasmonic Au-nanoparticles results in light-responsive smart materials.
Article
Chemistry, Multidisciplinary
Hang Zhang, Alan Z. Zoubi, Meredith N. Silberstein, Charles E. Diesendruck
Summary: Mechanochemistry can cause the degradation of covalent macromolecules, including block copolymers. By preparing polymers with different ratios of butyl acrylate and methyl methacrylate and subjecting them to ultrasonication, it was found that the mechanochemistry rate constant of all BCPs was similar to that of the methacrylate homopolymer, regardless of the amount of the methacrylate monomer. Size-exclusion chromatography revealed the presence of a secondary selective scission site at the covalent connection between the two blocks. Molecular dynamics modeling showed that dynamic phase separation of the blocks induced an unusual distribution of applied forces, leading to force focusing at the interface.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Sapir Willdorf-Cohen, Alexander Kaushansky, Dario R. Dekel, Charles E. Diesendruck
Summary: This study discusses the impact of solvent molecules on chemical reactions, particularly through the electronic interactions in ion microsolvation. Using the reaction between hydroxide and quaternary ammonium salts as an example, it demonstrates how water microsolvation can alter the chemical selectivity of hydroxide. The reactivity of hydroxide as a base is more affected by water microsolvation than its reactivity as a nucleophile.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
