Article
Chemistry, Multidisciplinary
Falk Ebeler, Yury V. Vishnevskiy, Beate Neumann, Hans-Georg Stammler, Rajendra S. Ghadwal
Summary: Mesoionic dithiolates ligands were synthesized by reacting with elemental sulfur, and were then used to form germylene and catenation products with other compounds. The structures and electronic properties of these compounds were studied.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Inorganic & Nuclear
Christopher Barnett, Marcus L. Cole, Jason B. Harper
Summary: This article discusses the impact of steric factors on electronic probes, highlighting the particular sensitivity of selenium adducts. It serves as a reminder to always critically evaluate what a probe is measuring.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Arne Merschel, Yury V. Vishnevskiy, Beate Neumann, Hans-Georg Stammler, Rajendra S. Ghadwal
Summary: An unprecedented ring-opening of mesoionic carbenes (iMICs) based on an 1,3-imidazole scaffold to yield N-ethynylformimidamide (eFIM) derivatives as crystalline solids. The eFIMs are thermally stable under an inert atmosphere and show moderate air stability. They are excellent surrogates of iMICs and readily undergo ring-closing click reactions with a variety of main-group as well as transition metal Lewis acids to form challenging iMIC-compounds in good to excellent yields.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Sebastian Mummel, Felix Lederle, Eike G. Huebner, Jan C. Namyslo, Martin Nieger, Andreas Schmidt
Summary: Sydnone methides are a class of mesoionic compounds with exocyclic carbon substituents. In this study, new sydnone methides were prepared and characterized. They can be represented by mesomeric structures with exocyclic carbanionic groups or with exocyclic C=C double bonds as a common feature.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Zhaowen Dong, J. Terence Blaskovits, Farzaneh Fadaei-Tirani, Rosario Scopelliti, Andrzej Sienkiewicz, Clemence Corminboeuf, Kay Severin
Summary: The study found that mesoionic imidazolylidenes bearing a diphenyltriazinyl (Dpt) substituent exhibit improved pi-acidic properties compared to Arduengo-type N-heterocyclic carbenes. This discovery was supported by computational analysis and experimental evidence. The new carbene was utilized to stabilize a low-valent paramagnetic tin compound, demonstrating its usefulness.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Sebastian Mummel, Felix Lederle, Eike G. Huebner, Jan C. Namyslo, Martin Nieger, Andreas Schmidt
Summary: Sydnone methides are rare compounds that can form pi-electron rich anionic N-heterocyclic carbenes and coordinate with various metals, while also undergoing C-C coupling reactions under specific catalysts. Studies have determined their electronic properties and NMR spectra.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Applied
Emmanuel Campos-Dominguez, Jose Vasquez-Perez, Susana Rojas-Lima, Heraclio Lopez-Ruiz, Daniel Mendoza-Espinosa
Summary: This study describes the synthesis and characterization of a series of novel compounds, as well as the evaluation of their catalytic activity in organic reactions.
APPLIED ORGANOMETALLIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Hannah K. Wagner, Hubert Wadepohl, Joachim Ballmann
Summary: A metal-templated synthetic route to cyclic (aryl)(ylidic) mesoionic carbenes (CArY-MICs) with an endocyclic P-ylide is presented. This approach allows controlled cyclisation of a P,P'-diisopropyl-substituted 2,2'-diphosphinotolane and formation of chelate complexes coordinated by a phosphine donor and the CArY-MIC carbon atom. The reversible formation of P-C bonds in the presence of a third fac-positioned open coordination site was demonstrated in molybdenum complexes.
Article
Chemistry, Inorganic & Nuclear
Kouki Matsubara, Kanta Tomomatsu, Ayame Tajiri, Arisa Watanabe, Yuji Koga, Ryuta Ishikawa, Yuji Yamada
Summary: This article describes the synthesis and characterization of a series of tridentate pincer-type triazolylidene nickel(II) complexes. Compared to commonly used N-heterocyclic carbene nickel(II) complexes, these complexes exhibit distinct properties and require different conditions for catalytic cross-coupling reactions.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Ravi Kumar, Madhusudan K. Pandey, Indresh K. Pandey, Abhishek Kumar, Joyanta Choudhury
Summary: Here, we present the synthesis and characterization of the first mesoionic carbene (MIC)-Mn(I) complex Mn-bim-MICimz derived from imidazolylidene motif. The octahedral Mn(I) complex Mn-bim-MICimz was constructed with an anionic benzimidazolato-anchored imidazolylidene MIC-based bidentate ligand (bim-MICimz) and four CO ligands, as confirmed by various analytical techniques. The bim-MICimz ligand is expected to form a stable bond with the Mn(I) center and enhance the electron density at the Mn(I) center due to its stronger s-donating and weaker p-accepting properties. This complex shows potential in catalytic hydrogenation reactions involving N-heteroarenes.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Arne Merschel, Timo Glodde, Beate Neumann, Hans-Georg Stammler, Rajendra S. Ghadwal
Summary: This study reports the intramolecular 1,2-Dipp migration of seven mesoionic carbenes under nickel catalysis to generate 1,3-imidazoles. The use of these compounds to access super-iMICs demonstrates their superior stereoelectronic properties. The results reveal unprecedented reaction pathways in NHC chemistry.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Lea Dettling, Niklas Limberg, Raphaela Kueppers, Daniel Frost, Manuela Weber, Nathan T. Coles, Diego M. Andrada, Christian Mueller
Summary: Trimethylsilyl-substituted triazaphospholes were synthesized via a [3+2] cycloaddition reaction, leading to the formation of unprecedented BF3 adducts of triazaphosphol-5-ylidenes during the attempted isolation of their N-alkylated products. The nature of the carbon(carbene)-boron bond was studied within the DFT framework, revealing strong electron donation from the carbene carbon atom to the boron atom combined with weak back-bonding.
CHEMICAL COMMUNICATIONS
(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, Applied
Carlos Angel-Jijon, David Rendon-Nava, Josue G. Fonseca-Olvera, Daniel Mendoza-Espinosa, Alejandro Alvarez-Hernandez
Summary: We have synthesized and fully characterized a new series of indole-derived triazolium salts and their corresponding triazolylidene gold, palladium, rhodium, and iridium complexes. The structures of all new compounds were determined by H-1 and C-13 NMR spectroscopy, elemental analyses, and single crystal X-ray diffraction for triazoliums 1 and 2 and complexes 3, 4, and 9. The gold complexes exhibited good catalytic performance in the hydrohydrazination of terminal alkynes, producing substituted hydrazones in high yields under mild conditions. Additionally, the iridium complex (9) showed excellent catalytic activity in the transfer hydrogenation of ketones and aldehydes using isopropanol as the hydrogen source.
APPLIED ORGANOMETALLIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Jessica Stubbe, Simon Suhr, Julia Beerhues, Maite Noessler, Biprajit Sarkar
Summary: The study reported the synthesis of a new methylene-bridged bis-triazolium salt as a precursor, which was used to prepare a novel carbene-silver(i) complex through metalation. The research also investigated the structural changes and chemical transformations that occurred during the process.
Article
Chemistry, Multidisciplinary
Mahendra K. Sharma, Dennis Rottschafer, Beate Neumann, Hans-Georg Stammler, Sergi Danes, Diego M. Andrada, Maurice van Gastel, Alexander Hinz, Rajendra S. Ghadwal
Summary: Metalloradicals play important roles in synthesis, catalysis, and bioinorganic chemistry. This study reports two iron radical cation complexes and investigates their oxidation reactions and structural features.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Review
Chemistry, Multidisciplinary
Rajendra S. Ghadwal
Summary: This paper discusses the tuning of structure and properties of main-group species (E) by controlling pi-conjugation and/or pi-donation using classical N-heterocyclic vinyl (NI-IV) ligands. By selecting appropriate carbene units, the electronic structure of derived species can be precisely controlled, resulting in stable solid materials.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Henric Steffenfauseweh, Yury V. Vishnevskiy, Beate Neumann, Hans-Georg Stammler, Diego M. Andrada, Rajendra S. Ghadwal
Summary: In this study, the synthesis, characterization, and reactivity of the first cyclic C2As2-diradicaloid compound were reported. The compound exhibits a planar C2As2 ring, is diamagnetic, and shows well resolved NMR signals.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Falk Ebeler, Yury V. Vishnevskiy, Beate Neumann, Hans-Georg Stammler, Rajendra S. Ghadwal
Summary: Mesoionic dithiolates ligands were synthesized by reacting with elemental sulfur, and were then used to form germylene and catenation products with other compounds. The structures and electronic properties of these compounds were studied.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Review
Chemistry, Inorganic & Nuclear
Lothar Weber, Falk Ebeler, Rajendra S. Ghadwal
Summary: Dipnictenes, molecules with a double bond between two Group 15 elements, have made remarkable progress in recent years. The introduction of new ligand systems and non-carbon donor substituents has led to the discovery of numerous dipnictenes with diverse properties. Stable N-heterocyclic carbenes and other singlet carbenes have also been utilized in the synthesis of related unsaturated species. A comprehensive understanding of the structure, bonding, and reactivity of dipnictenes and the influence of substituents on their properties is crucial for advancements in the field.
COORDINATION CHEMISTRY REVIEWS
(2022)
Article
Chemistry, Multidisciplinary
Henric Steffenfauseweh, Dennis Rottschaefer, Yury V. Vishnevskiy, Beate Neumann, Hans-Georg Stammler, Dariusz W. Szczepanik, Rajendra S. Ghadwal
Summary: A bordeaux-red solid compound based on an anionic dicarbene (ADC) with a central six-membered C4Sb2 ring is reported. The compound undergoes 2 e-oxidation to form a brick-red solid with unpaired electrons and lone pairs. The diradical character of the compound is calculated to be 36-39% according to different methods.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Arne Merschel, Dennis Rottschaefer, Beate Neumann, Hans-Georg Stammler, Mark Ringenberg, Maurice Van Gastel, T. Ilgin Demirer, Diego M. M. Andrada, Rajendra S. S. Ghadwal
Summary: In this study, we have successfully synthesized and isolated two stable anions K[SIPrBp] (4 a-K) and K[IPrBp] (4 b-K). These anions, derived from classical N-heterocyclic carbenes (NHCs), exist as violet crystalline solids.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Multidisciplinary
Rajendra S. Ghadwal
Summary: This review article aims to highlight recent advances in accessing stable iMICs, quantifying their properties, and exploring their applications in synthesis and catalysis. The synthetic viability and use of vicinal C4,C5-anionic dicarbenes (ADCs) based on a 1,3-imidazole framework are also presented. iMICs and ADCs have the potential to push the limit of classical NHCs by enabling access to conceptually new main-group heterocycles, radicals, molecular catalysts, ligand sets, and more.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Arne Merschel, Yury V. Vishnevskiy, Beate Neumann, Hans-Georg Stammler, Rajendra S. Ghadwal
Summary: Cyclic organoalane compounds [(ADC(Ar))AlH2](2) based on anionic dicarbene (ADC) frameworks have been reported. These compounds are stable crystalline solids and soluble in organic solvents. They exhibit annulated tricyclic structures with a planar central C4Al2-core embedded between two peripheral 1,3-imidazole rings.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Falk Ebeler, Yury V. Vishnevskiy, Beate Neumann, Hans-Georg Stammler, Rajendra S. Ghadwal
Summary: The decarbonylation of a cyclic bis-phosphaethynolatostannylene [(ADC)Sn(PCO)](2) based on an anionic dicarbene framework and under UV light results in the formation of a Sn2P2 cluster compound [(ADC)SnP](2). The [(ADC)SnP](2) compound binds reversibly with CO2 and enables catalytic hydroboration reaction with CO2. Additionally, it reacts with elemental selenium and Fe-2(CO)(9) to form corresponding compounds.
Article
Chemistry, Multidisciplinary
Arne Merschel, Yury V. Vishnevskiy, Beate Neumann, Hans-Georg Stammler, Rajendra S. Ghadwal
Summary: An unprecedented ring-opening of mesoionic carbenes (iMICs) based on an 1,3-imidazole scaffold to yield N-ethynylformimidamide (eFIM) derivatives as crystalline solids. The eFIMs are thermally stable under an inert atmosphere and show moderate air stability. They are excellent surrogates of iMICs and readily undergo ring-closing click reactions with a variety of main-group as well as transition metal Lewis acids to form challenging iMIC-compounds in good to excellent yields.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Inorganic & Nuclear
Anna Hanft, Dennis Rottschafer, Victoria Mueller, Pascal Weinberger, Krzysztof Radacki, Xiulan Xie, Crispin Lichtenberg
Summary: The installation of electron-withdrawing functional groups at the carbocyclic backbone of aminotroponiminate (ATI) ligands is a versatile method for influencing the electronic properties of the resulting ATI complexes. In this study, Li, Na, and K salts of an ATI ligand with a phenylsulfinyl substituent in the backbone were reported. The sulfinyl group was found to actively contribute to the coordination chemistry of these complexes, competing effectively with neutral donor ligands in various states.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Inorganic & Nuclear
Arne Merschel, Yury V. Vishnevskiy, Beate Neumann, Hans-Georg Stammler, Rajendra S. Ghadwal
Summary: Phosphino-functionalized mesoionic olefins derived from a 1,3-imidazole-based mesoionic carbene have been reported. They exhibit remarkable basicity and their chemical properties and structures have been characterized.
DALTON TRANSACTIONS
(2022)
