Article
Chemistry, Multidisciplinary
Florian Schoen, Lukas M. Sigmund, Friederike Schneider, Deborah Hartmann, Matthew A. Wiebe, Ian Manners, Lutz Greb
Summary: This study developed a transition metal-free catalyst for the preparation of high molar weight polyphosphinoboranes, overcoming the interference of transition metal impurities on the reproducibility of material properties.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Review
Chemistry, Physical
Krishna K. Manar, Jing Cheng, Yang Yang, Xuemei Yang, Peng Ren
Summary: In the past two decades, pincer metal complexes have been widely used as catalysts for various organic transformations. With their extraordinary chemical characteristics, they have been extensively utilized to generate novel catalytic species. These complexes exhibit high atom economy and eco-friendly routes, and have shown excellent catalytic behavior in hydrogenation reactions of CO2, nitriles, amides, esters, olefins, and alkynes. This review highlights the functioning and mechanistic studies of pincer metal complexes in these hydrogenation reactions, and provides outlooks and suggestions for future research.
Review
Chemistry, Inorganic & Nuclear
Richard A. Manzano, Rowan D. Young
Summary: The PCcarbeneP pincer ligands were slow to develop after their discovery in the early 20th century, but have seen renewed activity in the last 10-15 years, with practical solutions allowing for their application on various metals. These ligands exhibit unique reactivity and diversity, showing the ambiphilic nature of the carbene position.
COORDINATION CHEMISTRY REVIEWS
(2021)
Article
Chemistry, Physical
Soumi Chakraborty, Amit Biswas, Swadhin K. Mandal
Summary: A redox-active phenalenyl ligand coordinated Mn(III)-complex can be reduced to generate a catalyst with a ligand-centered radical. This chemically reduced Mn-catalyst exhibits excellent catalytic reactivity for silylative dehydration of various primary amides using an inert and affordable silane, PMHS. Control experiments support a radical pathway initiated by the ligand-centered radical.
Article
Chemistry, Physical
Soumi Chakraborty, Amit Biswas, Swadhin K. Mandal
Summary: A chemically reduced Mn-catalyst, generated by the reduction of a redox-active phenalenyl ligand coordinated Mn(III)-complex, exhibits excellent catalytic reactivity for the silylative dehydration of a wide range of primary amides to synthesize nitriles under mild conditions. Control experiments support a radical pathway initiated by the ligand-centered radical in the catalytic reaction.
Article
Chemistry, Inorganic & Nuclear
Krishnendu Paramanik, Nilaj Bandopadhyay, Gayetri Sarkar, Souvik Chatterjee, Suvojit Roy, Subhra Jyoti Panda, Chandra Shekhar Purohit, Bhaskar Biswas, Hari Sankar Das
Summary: The sustainable production of privileged amines through the catalytic reduction of nitriles using an inexpensive silane polymethylhydrosiloxane (PMHS) shows promise as a replacement for traditional synthetic routes that involve expensive metal catalysts. Nickel(ii) and cobalt(ii) complexes with a redox-active imino-o-benzoquinonato ligand were designed and characterized, showing excellent catalytic activity in transforming various organonitriles into corresponding primary amines selectively using PMHS. The important role of the non-innocent imino-o-benzoquinonato ligand and metal(ii) ion cooperativity in controlling the reactivity and selectivity of the metal-hydride intermediates during catalytic reduction was revealed through control experiments and computational calculations.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Physical
Kevin Schlenker, Elizabeth G. Christensen, Asylbek A. Zhanserkeev, Gabriel R. McDonald, Emily L. Yang, Kevin T. Lutz, Ryan P. Steele, Ryan T. VanderLinden, Caroline T. Saouma
Summary: The study reveals that substrate binding to the backbone of the catalyst is advantageous for the hydrogenation of CO2, contrary to previous assumptions. The enhanced hydricity observed upon deprotonation may have broad applicability to systems capable of undergoing metal-ligand cooperativity. This work demonstrates the use of thermochemical analysis to advance mechanistic understanding in (de)hydrogenation catalysis.
Article
Chemistry, Multidisciplinary
Shambhu Nath, Ekta Yadav, Abhinav Raghuvanshi, Amrendra K. K. Singh
Summary: A set of ruthenium(II)-protic-N-heterocyclic carbene complexes interconvertible by acid-base chemistry are reported. The charge segregation in anionic-NHC complexes and their cooperative small molecule activation are described. The activation of CO2 using anionic NHC complex and subsequent conversion to formate is of potential importance in renewable energy and sustainable development.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Pasquale Mastropierro, Andrew W. J. Platten, Alan R. Kennedy, Eva Hevia, Marina Uzelac
Summary: By exploiting the bimetallic cooperation of alkali-metal manganate (II) complexes, oxidative homocoupling of terminal alkynes can be efficiently promoted to form conjugated 1,3-diynes. The influence of alkali-metal on these bond forming processes has been studied, and it has been found that initial metalation of the alkyne is required for the homocoupling to occur. The tetra(alkyl) alkali-metal manganates behave as polybasic reagents, easily deprotonating the alkynes.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Han-Ying Liu, Ryan J. Schwamm, Michael S. Hill, Mary F. Mahon, Claire L. McMullin, Nasir A. Rajabi
Summary: The reactivity of copper-alumanyl complexes is dependent on the identity of the carbene co-ligand, suggesting an ambiphilicity in the Cu-Al interaction. This divergent reactivity with carbodiimides and CO2 implies a complex relationship between the two metals in the complex.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Daniel Roth, Thaddaeus Thorwart, Clara Douglas, Lutz Greb
Summary: The first bis(amidophenolato)phosphonium salts were prepared and found to be highly Lewis acidic, with a strong affinity for fluoride and hydride ions. This affinity enabled the salts to undergo new reactions and expand their reactivity portfolio. The properties and reactions were thoroughly investigated through theory and experiments.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Physical
Daniele Perilli, Raffaella Breglia, Cristiana Di Valentin
Summary: This article explains the electronic properties of single atom catalysts (SACs) embedded in 2D materials from the perspective of coordination chemistry. It highlights the role of the type of 2D material in determining the spin, charge, and stability of SACs.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Multidisciplinary
Joseph A. Zurakowski, Brady J. H. Austen, Maeve C. Dufour, Denis M. Spasyuk, David J. Nelson, Marcus W. Drover
Summary: The study demonstrates the importance of thoughtful ligand design in the intermolecular activation of iodobenzene in catalytic reactions. A specific nickel complex has shown excellent reactivity in this reaction. Furthermore, the secondary coordination sphere has been shown to have a significant impact on the formation of reaction products.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Claire N. Brodie, Lia Sotorrios, Timothy M. Boyd, Stuart A. Macgregor, Andrew S. Weller
Summary: The dehydropolymerization of H3B • NMeH2 to form N-methylpolyaminoborane using neutral and cationic catalysts based on the {Ir(iPr-PNHP)} fragment has been studied. The cationic catalysts showed higher activity and selectivity compared to the neutral catalysts. Density functional theory calculations revealed the mechanism of the amine-borane dehydrogenation and suggested a lower barrier for the cationic system.
Article
Chemistry, Physical
Javier Corpas, Enrique M. Arpa, Romain Lapierre, Ines Corral, Pablo Mauleon, Ramon Gomez Arrayas, Juan C. Carretero
Summary: The cooperative action of the acetate ligand, the 2-pyridyl sulfonyl directing group, and the palladium catalyst is crucial for controlling reactivity, regioselectivity, and stereoselectivity in the acetoxylation of unsymmetrical internal alkynes. Insight into the roles of the acetate ligand in the reaction mechanism is provided by experimental and computational analyses, contributing to a better understanding of the observed regiocontrol.
Article
Chemistry, Physical
Michelle Ernst, Tomasz Poreba, Lars Gnaegi, Ganna Gryn'ova
Summary: Molecular docking, combined with DFT-level geometry optimizations, accurately locates guest molecules in metal-organic frameworks and enhances their properties. This method can be used as a computational alternative when experimental structures are unavailable. It provides insights into the adsorption sites and structures, as well as the interaction energies, of host-guest complexes in MOFs.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Selina Hollstein, Philipp Erdmann, Andreas Ulmer, Henrik Loew, Lutz Greb, Max von Delius
Summary: The dynamic covalent chemistry of the Si-O bond has unique opportunities but is rarely used to assemble discrete molecular architectures, possibly due to the harsh conditions required for exchange reactions at silicon in aprotic solvents. In this study, we provide a comprehensive account on the reaction of trialkoxysilanes with alcohols and identify mild conditions for rapid exchange in aprotic solvents. We uncover, understand, and exploit the effects of substituents, solvent, and salt for the construction of sila-orthoester cryptates, which show a sharp, divergent pH-response attractive for future applications beyond host-guest chemistry, such as drug delivery.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Rezisha Maskey, Thaddaeus Thorwart, Simone F. Ebel, Angelina Jocic, Deborah Hartmann, Lutz Greb
Summary: Stable metal-free diradicaloids with modifiable nitrogen-containing frameworks can be synthesized through Lewis acid-base pair formation. This method allows for the one-step synthesis of diradicaloids with rationally adjustable diradical character, presenting great potential for various applications.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Inorganic & Nuclear
Qingqing Luo, Lutz Greb
Summary: Organosilanes are crucial products in the chemical industries, but their bulk production starting from silica has a significant ecological impact due to energy consumption and hazardous by-products. In this study, a redox-neutral, one-pot silicon-carbon bond formation process was developed using catechol-mediated SiO2 depolymerization and nucleophilic substitution. By optimizing the steps, a 76% yield of SiPh4 was achieved on a large scale. This success encourages further research on energy- and waste-efficient organosilane production.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Michelle Ernst, Ganna Gryn'ova
Summary: Metal-organic frameworks (MOF) and covalent organic frameworks (COFs) have potential as nanocarriers for targeted drug delivery. Noncovalent interactions between frameworks and drugs play a crucial role in drug uptake and release. This study demonstrates a good agreement between experimentally measured release metrics and in silico computed host-guest interaction energies for a range of drugs and frameworks. The findings suggest that framework functional groups significantly impact the strength of host-guest interactions and that a given framework can be an efficient delivery agent for various drugs beyond the typical ones.
HELVETICA CHIMICA ACTA
(2023)
Article
Chemistry, Physical
Stiv Llenga, Ganna Gryn'ova
Summary: Chemical machine learning relies on unique and informative representations of molecules. We present the matrix of orthogonalized atomic orbital coefficients (MAOC) as a quantum-inspired molecular and atomic representation that contains both structural and electronic information. MAOC is suitable for representing a wide range of chemical systems and shows accuracy similar or superior to other representations for various chemical properties.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Multidisciplinary Sciences
Benedikt Rennekamp, Christoph Karfusehr, Markus Kurth, Aysecan uenal, Debora Monego, Kai Riedmiller, Ganna Gryn'ova, David M. Hudson, Frauke Graeter
Summary: The authors used scale-bridging simulations to identify breakage points in collagen and studied the mechanical and chemical impact of these ruptures on the tissue. They found that collagen has a unique failure mode that helps prevent material ageing and macroscopic failure.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Ute Wild, Olaf Huebner, Paul Meiners, Elisabeth Kaifer, Markus Enders, Hans-Joerg Himmel
Summary: By using unconventional synthesis protocols, researchers have successfully connected two redox-active triguanidine units through a dithiolate bridge. They achieved intramolecular through-space double-electron transfer between the two units at low temperatures, and observed chemical exchange between different redox states. These findings provide detailed quantitative insights into the factors influencing intramolecular through-space double-electron transfer processes.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Christian Iwanov, Moritz Philipp Hopp, Domenik Lorenz, Joachim Ballmann, Markus Enders
Summary: Iron ions in a square-planar coordination have the ability to bind and transform molecules, making them important for stoichiometric and catalytic reactions. This research successfully studied the interaction between iron ions and surrounding ligands, as well as their catalytic activity in oxidation-reduction reactions, using a phthalocyanine derivative.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Review
Chemistry, Physical
Rostislav Fedorov, Ganna Gryn'ova
Summary: This review discusses modern in-silico techniques for predicting the reduction and oxidation potentials of organic molecules. These techniques go beyond conventional first-principles computations and thermodynamic cycles and involve the use of complex descriptors and machine learning algorithms. The review also provides a list of currently available data sets for redox-active organic molecules to facilitate the development of screening platforms and rational design.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Multidisciplinary
Ravi Yadav, Paul Janssen, Marcel Schorpp, Lutz Greb
Summary: Anti-van't Hoff-Le Bel configured p-blockelementspecies possess intrinsically high reactivity and are thus challenging to isolate. Consequently, numerous elements in this configuration, including square-planar germanium(IV), remain unexplored. Herein, we follow a concept to reach anti-van't Hoff-Le Bel reactivity by ligand dissociation from a rigid calix[4]pyrrole germanein its bis(thf) adduct. While the macrocyclic ligand assures square-planar coordination in the uncomplexed form, the labile thf donors provide robustness for isolation on a multigram scale. Unique properties of a low-lying acceptor orbital imparted to germanium(IV) can be verified, e.g., by isolating an elusive anionic hydrido germanate and exploiting it for challenging bond activations. Aldehydes, water, alcohol, and a CN triple bond are activated for the first time by germanium-ligand cooperativity. Unexpected behaviors against fluoride ion donors disclose critical interferences of a putative redox-coupled fluoride ion transfer during the experimental determination of Lewis acidity. Overall, we showcase how ligand lability grants access to the uncharted chemistry of anti-van't Hoff-Le Bel germanium(IV) and line up this element as a member in the emerging class of structurally constrained p-block elements.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Daniel Roth, Alexander T. Radosevich, Lutz Greb
Summary: A series of structurally constrained phosphenium ions based on pyridinylmethylamidophenolate scaffolds are capable of undergoing P(III)/P(V) oxidative addition reactions with C-H bonds in alkynes, alkenes, and arenes. The reactions are reversible and involve isomerizations and phosphorus-ligand cooperative effects.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Lutz Greb
Summary: In recent decades, numerous strategies have been developed to enhance the reactivity and properties of p-block elements. This Account focuses on our approaches to controlling p-block elements in their normal oxidation states using distinct ligands. Catecholato ligands on silicon, germanium, or phosphorus offer a range of rewarding properties, such as Lewis superacidity. The synthesized species can be utilized for catalysis and bond activation, enriching the chemistry of main-group elements.
Review
Chemistry, Physical
Michelle Ernst, Jack D. Evans, Ganna Gryn'ova
Summary: The performance of metal-organic and covalent organic framework materials in important applications such as gas capture, storage, and separation heavily relies on the interactions established inside their pores. Computational modeling provides detailed information about these interactions at a level of precision often unachievable through experiments. The review summarizes key simulation techniques, presents examples of their use in organic framework hosts analysis and design, and discusses high-throughput screening and machine learning techniques for predicting their properties and performances.
CHEMICAL PHYSICS REVIEWS
(2023)
Article
Chemistry, Inorganic & Nuclear
Willi Keller, Matthias Hofmann, Hubert Wadepohl, Markus Enders, Jindrich Fanfrlik, Drahomir Hnyk
Summary: This study discovered a new compound SeB9Cl9 through the vacuum co-pyrolysis reaction and characterized its molecular structure and chemical properties using various techniques. The research also demonstrated the exceptional stability of octahedral, bicapped square-antiprismatic, and icosahedral closo motifs in the SeBnCln family.
DALTON TRANSACTIONS
(2023)
