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, 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, 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, Physical
Viet-Hung Do, P. Prabhu, Yinghao Li, Wenjie Xie, Pinit Kidkhunthod, Guangzhao Wang, Xin Wang, Jong-Min Lee
Summary: Transition metal nitrides with atomically thin Os nanoclusters confined on 2D 6-MoN exhibit enhanced catalytic performance, particularly in hydrogen evolution, due to optimized surface electron configurations and abundant active sites.
Article
Chemistry, Multidisciplinary
Jana Hatzfeld, Steffen Skowaisa, Elisabeth Jackel, Julia Kaufmann, Edgar Haak
Summary: Various triaminocyclopentadienyl ruthenium complexes were synthesized from Ru-3(CO)(12) and tested for their ability to catalyze cascade conversions of propargyl alcohols. The substrate scope of catalytic cycloadditions was extended to terpenoid-derived propargyl alcohols containing an internal alkyne moiety, resulting in a wide range of cyclic terpenoid and phloroglucinol adducts obtained by complementary application of both types of catalysts.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Biochemistry & Molecular Biology
Pavel S. Gribanov, Anna N. Philippova, Maxim A. Topchiy, Lidiya Minaeva, Andrey F. Asachenko, Sergey N. Osipov
Summary: An efficient method for accessing novel 5-(het)arylamino-1,2,3-triazole derivatives has been developed using Buchwald-Hartwig cross-coupling reaction. The most active catalyst for the process, palladium complex [(THP-Dipp)Pd(cinn)Cl] with expanded-ring N-heterocyclic carbene ligand, affords the target molecules in high yields.
Review
Chemistry, Inorganic & Nuclear
Dhanushi Welideniya, Mridhul R. K. Ramachandran, Tim Kalisch, Rainer Streubel
Summary: This review comprehensively covers the synthetic concepts and breakthroughs in 1,4-diphosphinine and related P-bridged bis(NHCs) chemistry over the past four decades, highlighting theoretical aspects, fundamental characteristics, and a broad platform for reactions. It also discusses recent developments in tricyclic P-bridged bis(imidazole-2-ylidenes) and presents new perspectives for potential applications in molecular and materials chemistry.
DALTON TRANSACTIONS
(2021)
Article
Chemistry, Physical
Dawid Zych
Summary: This study focuses on the theoretical investigations of mono- and dinuclear complexes, utilizing density functional theory calculations to understand their optical properties and physical parameters. The results have significant implications for the field of chemistry and materials science.
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, Organic
Letizia Molteni, Camilla Loro, Michael S. Christodoulou, Marta Papis, Francesca Foschi, Egle M. Beccalli, Gianluigi Broggini
Summary: In this study, the ruthenium-catalyzed transformation of 4-alkenyl-substituted isoxazol-5-ones to 1H-pyrrole derivatives was reported. The reaction was also effective on cyclohexane-fused isoxazolones, leading to the formation of 4,5,6,7-tetrahydroindoles. The access to tri- and tetra-substituted pyrroles was achieved through decarboxylative ring-opening/ring-closure involving C-H functionalization of the alkenyl moiety.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Kaili Yan, Hyuna Kwon, Morgan Huddleston, De-en Jiang, Yujie Sun
Summary: Electrocatalytic biomass valorization has gained increasing interest, but reports on pyridine-containing chemicals from biomass upgrading are rare. In this study, we describe an electrochemical synthesis of 3-pyridinol from biomass-derived furfurylamine, achieving a 97% yield. The use of a Br-/Br+ redox cycle and strong acidic conditions was crucial for driving the final dehydration step. Control experiments and computational investigations were conducted to elucidate the key mechanistic steps of the one-pot conversion of furfurylamine to 3-pyridinol.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Devon E. Chapple, Paul D. Boyle, Johanna M. Blacquiere
Summary: New members of the [Ru(Cp/Cp*)(P2N2R ')(MeCN)]PF6 catalyst family were synthesized, among which a derivative showed relatively high stability due to a specific coordination mode of the ligand protecting the low-coordinate metal ion. Different derivatives of the catalyst family exhibited varied features, such as the capability to activate chlorine atoms in organic solvents.
Article
Chemistry, Multidisciplinary
Ramapada Dolai, Rahul Kumar, Benedict J. Elvers, Pradeep Kumar Pal, Benson Joseph, Rina Sikari, Mithilesh Kumar Nayak, Avijit Maiti, Tejender Singh, Nicolas Chrysochos, Arumugam Jayaraman, Ivo Krummenacher, Jagannath Mondal, U. Deva Priyakumar, Holger Braunschweig, Cem B. Yildiz, Carola Schulzke, Anukul Jana
Summary: A new type of carbodicarbene (CDC) with two different classes of carbenes has been reported, which shows promising potential as organic electron donors and n-dopants. These compounds exhibit notable redox properties and can form carbon-carbon sigma bonds through reactions with [NO][SbF6].
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Arpan Das, Soumi Chakraborty, Swadhin K. Mandal
Summary: Abnormal N-heterocyclic carbene (aNHC) based Ni(II) pi-allyl complexes (3 and 4) were synthesized from a Ni(0) precursor and characterized. The mechanism for the formation of Ni(II) eta(3)-allyl complexes from a Ni(0) precursor using a free abnormal N-heterocyclic carbene was elucidated. Exposure of complex 3 to O-2 gas under ambient pressure resulted in the activation of molecular oxygen to form a mu-hydroxo bridged Ni(II) dimer.
CHEMISTRY-AN ASIAN JOURNAL
(2021)
Article
Chemistry, Physical
Ryohei Doi, Koji Shimizu, Yuma Ikemoto, Masashi Uchiyama, Mikiko Koshiba, Atsushi Furukawa, Katsumi Maenaka, Satoshi Watanabe, Yoshihiro Sato
Summary: This study reports a nickel-catalyzed cascade reaction to construct a 3-acylbenzo[b]furan skeleton. Through reaction condition optimization, the catalyst loading could be reduced to 5-10 mol %, leading to the synthesis of various functionalized compounds. Stoichiometric study of nickel complexes and DFT calculations were conducted to support a possible reaction mechanism.
Article
Chemistry, Multidisciplinary
Andreas C. Hans, Patrick M. Becker, Johanna Haussmann, Simon Suhr, Daniel M. Wanner, Vera Lederer, Felix Willig, Wolfgang Frey, Biprajit Sarkar, Johannes Kaestner, Rene Peters
Summary: This article discloses a catalyst type that enables highly efficient direct 1,4-additions. The catalyst is a zwitterionic entity, with acetate binding to negatively charged Cu-II and serving as a counterion for benzimidazolium. All three functionalities are involved in the catalytic activation. The productivity of maleimides increased by a factor greater than 300 compared to the literature (TONs up to 6700). High stereoselectivity and productivity were achieved for a wide range of other Michael acceptors as well. The polyfunctional catalyst, accessible in only 4 steps from N-Ph-benzimidazole with an overall yield of 96%, remained robust during catalysis, allowing for multiple reuse with nearly constant efficiency. Mechanistic studies, particularly using DFT, provided a detailed understanding of how the catalyst operates. The benzimidazolium unit stabilizes the coordinated enolate nucleophile and prevents the dissociation of acetate/acetic acid from the catalyst.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Inorganic & Nuclear
Jan Hormann, Olga Verbitsky, Xiaoyu Zhou, Beatrice Battistella, Margarete van der Meer, Biprajit Sarkar, Cunyuan Zhao, Nora Kulak
Summary: We synthesized and characterized Cu(ii) complexes CuL1-CuL6 with cyclen-based ligands. The ligands L-1-L-6 comprise different donor sets including S and O atoms. The substitution of N donor atoms with hard donor O atoms leads to efficient oxidative nucleases, but dissociation of the complex upon reduction. We are showing that the rational combination of O and S atoms next to two nitrogen donors within the macrocycle leads to the stabilization of both redox states, resulting in the highest oxidative DNA cleavage activity within this family of cyclen-based Cu(ii) complexes.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Anna Pavun, Holger Kopacka, Klaus Wurst, Thomas Mueller, Florian R. Neururer, Stephan Hohloch, Benno Bildstein
Summary: A series of new heteroleptic cationic manganese(I) sandwich complexes, called tromancenium salts, were synthesized using high-power LED photochemistry and oxidation. These air-stable compounds exhibited reversible and quasi-reversible redox couples, unlike their less-substituted counterparts. The compounds were fully characterized using spectroscopy and crystal structure analysis.
JOURNAL OF ORGANOMETALLIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Peng Hou, Sebastian Peschtrich, Wolfram Feuerstein, Roland Schoch, Stephan Hohloch, Frank Breher, Jan Paradies
Summary: The synthesis of three new imidazolyl-substituted sulfur-containing heteroacenes is presented. These heteroacenes, composed of annelated benzo- and naphthothiophenes, serve as precursors for the generation of open-shell quinoid heteroacenes through oxidation with alkaline ferric cyanide. Spectroscopic and computational experiments provide evidence for the formation of reactive open-shell quinoids, which rapidly transform into paramagnetic polymeric materials.
Article
Chemistry, Multidisciplinary
Felix Stein, Simon Suhr, Arijit Singha Hazari, Robert Walter, Maite Noessler, Biprajit Sarkar
Summary: The synthesis and characterization of cationic azide-substituted 1,2,3-triazolium salts and their reactivity towards triphenylphosphine were reported. These salts were used as building blocks to develop unsymmetrical MIC-triazene-NHC/MIC' compounds which can be converted to radicals. The investigation of these radicals using various techniques sheds new light on the stabilization ability of MICs and their pi-accepting ability.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Felix Stein, Maite Noessler, Arijit Singha Hazari, Lisa Boeser, Robert Walter, Hang Liu, Elias Klemm, Biprajit Sarkar
Summary: In recent years, terpyridines (tpy) and mesoionic carbenes (MIC) have been widely used in metal complexes. In this study, a new class of complexes was obtained by combining PFC substituted tpy and MIC ligands within the same platform, and their structural, electrochemical and UV/Vis/NIR spectroelectrochemical properties were investigated. The resulting metal complexes were found to be potent electrocatalysts for CO2 reduction, with CO exclusively formed and a faradaic efficiency of 92%. A preliminary mechanistic study, including the isolation and characterization of a key intermediate, was also reported.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Inorganic & Nuclear
Maite Noessler, Rene Jaeger, David Hunger, Marc Reimann, Tobias Bens, Nicolas I. Neuman, Arijit Singha Hazari, Martin Kaupp, Joris van Slageren, Biprajit Sarkar
Summary: Due to their ability to form stable molecular complexes, terpyridine ligands with tailor-made properties are of great interest in chemistry and material science. By synthesizing two terpyridine ligands with different fluorinated phenyl rings, we were able to prepare Co-II and Fe-II complexes and investigate their properties using various analytical techniques. Our findings revealed the structural characteristics, electrochemical behavior, and magnetic properties of these complexes, providing valuable insights into their applications and potential uses.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Simon Suhr, Nicolai Schroter, Merlin Kleoff, Nicolas Neuman, David Hunger, Robert Walter, Clemens Lucke, Felix Stein, Serhiy Demeshko, Hang Liu, Hans -Ulrich Reissig, Joris van Slageren, Biprajit Sarkar
Summary: Two homoleptic Fe(II) complexes with superbasic terpyridine derivatives as ligands were studied to investigate the relationship between spin state and electrochemical/spectroscopic behavior. Antiferromagnetic coupling between a ligand-centered radical and the high-spin metal center resulted in an anodic shift of the first reduction potential and a mixed valency species with a moderately intense intervalence-charge-transfer band. The different spin states also influenced the electrochemical reactivity, with the low-spin species acting as a precatalyst for electrocatalytic CO2 reduction and showing a Faradaic efficiency of 37% for CO formation, while the high-spin species only catalyzed proton reduction with a modest Faradaic efficiency of approximately 20%.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Daniel Menia, Michael Pittracher, Holger Kopacka, Klaus Wurst, Florian R. Neururer, Daniel Leitner, Stephan Hohloch, Maren Podewitz, Benno Bildstein
Summary: Cobaltocenium carbaldehyde hexafluoridophosphate, a functionalized cobaltocenium salt, is obtained through a three-step synthetic sequence starting from cobaltocenium carboxylic acid. The compound shows unexpected reactivity due to the presence of a strongly electron-withdrawing cationic cobaltocenium moiety. Characterization of these formyl-cobaltocenium/cobaltocene compounds is done using various spectroscopy methods, crystal structure analysis, and density functional theory calculations.
Article
Chemistry, Multidisciplinary
Tobias Bens, Jasmin A. Kubler, Robert R. M. Walter, Julia Beerhues, Oliver S. Wenger, Biprajit Sarkar
Summary: We have developed new synthetic strategies to obtain a series of Ru(II) complexes with pyridyl-mesoionic carbene ligands. By replacing bpy ligands in [Ru(bpy)3]2+ with pyridyl-MIC ligands, we were able to isolate three new complexes. We analyzed their properties using NMR spectroscopy, single-crystal X-ray diffraction analysis, cyclic voltammetry, and other techniques. These complexes showed potential applications in photocatalysis and photosensitization.
ACS ORGANIC & INORGANIC AU
(2023)
Article
Chemistry, Multidisciplinary
Florian R. Neururer, Konstantin Huter, Michael Seidl, Stephan Hohloch
Summary: A rare niobium complex with a unique ligand has been synthesized and can be transformed into other compounds through chemical reactions, showing potential applications in catalysis and atom transfer reactions.
ACS ORGANIC & INORGANIC AU
(2023)
Article
Chemistry, Multidisciplinary
Julia Volk, Myron Heinz, Michael Leibold, Clemens Bruhn, Tobias Bens, Biprajit Sarkar, Max C. Holthausen, Ulrich Siemeling
Summary: Researchers have synthesized a novel cyclic compound with a 1,1'-ferrocenylene backbone, which exhibits unique structural and chemical properties. The compound's wide bond angle and redox-active backbone open up new possibilities for studying unconventional metalloradicals and oligoradicals.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Simon Suhr, Robert Walter, Julia Beerhues, Uta Albold, Biprajit Sarkar
Summary: In this contribution, we investigate Rh(iii) complexes with different substituted diamidobenzene ligands and show that the substituents on the ligands significantly affect the bonding, donor, electrochemical and spectroscopic properties of the Rh complexes. We also present design strategies for the isolation of mononuclear Rh(ii) metallates with high redox potentials and discover the reactivity of the metal complexes with small molecules.
Article
Chemistry, Inorganic & Nuclear
Maite Noessler, David Hunger, Nicolas Neuman, Marc Reimann, Felix Reichert, Mario Winkler, Johannes Klein, Tobias Bens, Lisa Suntrup, Serhiy Demeshko, Jessica Stubbe, Martin Kaupp, Joris van Slageren, Biprajit Sarkar
Summary: Controlling the spin state of metal complexes is crucial for manipulating their physical and chemical properties. Currently, this control is challenging due to the difficulties in precisely controlling the properties of the secondary coordination sphere. This study demonstrates that non-covalent interactions in the secondary coordination sphere can enable spin state control in metal complexes. By using fluorinated triazole ligands, mononuclear Co-II and Fe-II complexes with specific fluorinated benzyl substituents were synthesized and characterized. The spin state of the metal center was found to be influenced by the substituents and geometric structure, as revealed by magnetometry and spectroscopy. Quantum-chemical calculations provided insight into the role of fluorine-specific interactions. Notably, this work highlights the ability of the same fluorinated tripodal ligands to induce spin crossover behavior in both Fe-II and Co-II complexes.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Multidisciplinary
Ramananda Maity, Biprajit Sarkar
Summary: This paper provides an overview of recent developments in the field of 1,2,3-triazolylidene-type Mesoionic carbenes (MICs). These compounds are popular due to their modular synthesis and strong donor properties, and have found applications with both transition metals and main group elements. The paper discusses various aspects of MIC-containing compounds, including their synthesis, spectroscopic properties, and potential applications in catalysis and small-molecule activation.
