Article
Chemistry, Multidisciplinary
Jessica Rodriguez, Maxime Boudjelel, Leonard J. Mueller, Richard R. Schrock, Matthew P. Conley
Summary: This passage describes the reaction of W(NAr) ((C4H8)-C-13) (OSiPh3)(2) (1) with partially dehydroxylated silica at 700 degrees C. The results show that the reaction outcome is highly influenced by the reaction conditions. Different compounds are formed as products, and their formation is affected by light and heating treatment.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Review
Chemistry, Multidisciplinary
Maciej D. Korzynski, Christophe Coperet
Summary: One of the goals of modern catalysis science is to form single-site catalysts with uniform structure and identical affinity. Achieving such characteristics is challenging due to the complexity of surface chemical reactions. Surface organometallic chemistry has emerged as an effective method for forming well-defined species.
TRENDS IN CHEMISTRY
(2021)
Article
Chemistry, Inorganic & Nuclear
Michael R. Buchmeiser, Dominik Imbrich, Dongren Wang, Stefan Naumann
Summary: The authors synthesized a series of tungsten (VI) imido alkylidene N-heterocyclic olefin (NHO) complexes and found that the catalysts showed improved activity in ring-closing metathesis by adjusting the number and type of NHO ligands. The results indicate that further optimization of the catalysts' performance can be achieved by ligand tuning.
JOURNAL OF ORGANOMETALLIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Felix Ziegler, Hamzeh Kraus, Mathis J. Benedikter, Dongren Wang, Johanna R. Bruckner, Michal Nowakowski, Kilian Weisser, Helena Solodenko, Guido Schmitz, Matthias Bauer, Niels Hansen, Michael R. Buchmeiser
Summary: By utilizing cationic molybdenum imido alkylidene N-heterocyclic carbene (NHC) complexes confined in tailored ordered mesoporous silica, high macrocyclization selectivities up to 98% and high substrate concentrations up to 0.1 M can be achieved. Molecular dynamics simulations reveal that high conversions are a result of the proximity between the surface-bound catalyst and surface-located substrates, leading to increased reaction efficiency.
Article
Chemistry, Multidisciplinary
Mathis J. Benedikter, Janis V. Musso, Wolfgang Frey, Roman Schowner, Michael R. Buchmeiser
Summary: Despite their excellent selectivities and activities, Mo- and W-based catalysts for olefin metathesis have not been widely used due to their air sensitivity. The synthesized cationic-at-metal molybdenum and tungsten imido alkylidene NHC nitrile complexes are stable in air and can catalyze olefin metathesis reactions without prior activation. The presence of a nitrile ligand is crucial for their stability, while variations in imido and anionic ligands affect reactivities and stability.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Janis Musso, Jordan De Jesus Silva, Mathis J. Benedikter, Jonas Groos, Wolfgang Frey, Christophe Coperet, Michael R. Buchmeiser
Summary: Recent studies have shown that cationic d(0) group 6 olefin metathesis catalysts exhibit higher activity compared to their neutral counterparts, and their catalytic performance is greatly enhanced by immobilization on silica.
Article
Chemistry, Physical
Anne V. Le, Biplab Rajbanshi, Raul F. Lobo, Peng Bai
Summary: In this study, DFT calculations were used to investigate the mechanisms of propene metathesis catalyzed by WOx/SiO2. The results showed that there are still many mechanisms of heterogeneous catalyzed metathesis reactions that are not well understood. The pseudo-Wittig mechanism was found to be the most favorable method for generating initial alkylidene active sites. The allylic and vinylic C-H activations are more difficult and require the reduction of surface sites to W(+4).
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Adrian Sytniczuk, Mariusz Milewski, Michal Dabrowski, Karol Grela, Anna Kajetanowicz
Summary: A set of macrocyclic unsaturated musk compounds were obtained through a high-concentration RCM process, achieved by forming oligomers and then undergoing backbiting metathesis reaction. The process exhibited high selectivity and yielded pure macrocyclic musk products. The reaction conditions were user-friendly and environmentally friendly, using commercially available catalyst and bio-sourced oleic acid substrates.
Article
Chemistry, Multidisciplinary
Henrik Gulyas, Shigetaka Hayano, Adam Madarasz, Imre Papai, Mark Szabo, Agota Bucsai, Eddy Martin, Jordi Benet-Buchholz
Summary: By tuning the electron donor capacity of ligands, air-stable solid adducts of tungsten and molybdenum alkylidenes can be prepared, which can spontaneously release active catalysts in solution.
COMMUNICATIONS CHEMISTRY
(2021)
Article
Chemistry, Physical
Qiyang Zhang, Jabor Rabeah, Thanh Huyen Vuong, Tatiana Otroshchenko, Evgenii V. Kondratenko
Summary: The metathesis reaction of ethylene and 2-butene to produce propene is widely used in the chemical industry. MoOx-based supported catalysts show potential as alternatives to the currently employed WOx-containing systems. The activity of these catalysts depends on the formation of active Mo-carbene sites, which can be controlled by promoting the support with small amounts of alkali or alkaline earth metal oxides. The electronegativity of the additives affects olefin adsorption and carbene formation.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Alfred Worrad, Sagar Sourav, Stavros Caratzoulas, Dionisios G. Vlachos
Summary: The structure of supported MoOx/Al2O3 catalysts was investigated using AIMD and DFT. Phase diagrams were computed to understand the hydroxylation coverage under different conditions. The results showed that DFT is a cost-effective method for computing vibrational frequencies under certain hydrated conditions, but is susceptible to errors under dehydrated conditions. The power spectra of individual hydroxyls revealed a strong relationship between OH stretching frequencies and the surrounding coordination environment and MoOx anchoring location.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Ning Wei, Dazhi Zhang, Weiping Zhang, Shengjun Huang
Summary: Thermal treatment has limited impact on composite supported catalysts, but in this study, it has been observed that the calcination temperature directly affects the metathesis activity of tungsten-based catalysts supported on hierarchical ZSM-5 zeolite-alumina composite. As the calcination temperature increases, ethene conversion and metathesis activity also increase. The interaction between the W-oxo species and the zeolite's Bronsted acidic bridge hydroxyl groups play a significant role in this process.
Article
Chemistry, Multidisciplinary
Ning Wei, Lizhuo Wang, Wenjie Yang, Dazhi Zhang, Zhenghao Jia, Wei Liu, Weiping Zhang, Jiazhong Zang, Shengjun Huang, Jun Huang
Summary: The usage of hierarchical MFI zeolite enhances the catalytic performance of Mo-based catalysts for the olefin-metathesis reaction. The active catalysts are obtained through a segmental evolution track between hierarchical zeolite and Al2O3 slices for the formation of active sites. The working evolution track requires the engagement of intracrystalline mesoporous surface, Al2O3 slices, and zeolitic Bronsted acid sites.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Darryl F. Nater, Maxime Boudjelel, Lukas Laetsch, Richard R. Schrock, Christophe Coperet
Summary: Tungsten oxo adamantylidenes are a new class of easily accessible alkylidenes, which can be used to evaluate a wider range of molecular and supported olefin metathesis catalysts. The high thermal stability of the perfluoro-tert-butoxide complex, even in its dimer form, allows for grafting through sublimation. Evaluation of these supported species using standardized protocols demonstrates their high activity toward internal and terminal olefins.
HELVETICA CHIMICA ACTA
(2022)
Article
Chemistry, Physical
Adam A. Rajkiewicz, Anna Kajetanowicz, Karol Grela
Summary: New ruthenium olefin metathesis catalysts containing N-heterocyclic carbene (NHC) connected by a linker tether to a benzylidene ligand have been studied. These polymeric catalysts exhibited slightly lower activity compared to structurally related nonpolymeric catalysts, but have been successfully used in a number of ring-closing metathesis reactions to produce various heterocyclic compounds, including biologically and pharmacologically related analogues.
Article
Chemistry, Multidisciplinary
Steven Giese, Katrin Klimov, Antal Mikehazi, Zsolt Kelemen, Daniel S. Frost, Simon Steinhauer, Peter Mueller, Laszlo Nyulaszi, Christian Mueller
Summary: The yet unknown 2-amino-substituted lambda(3),sigma(2)-phosphinines are phosphorus-containing aniline derivatives. Our experimental and theoretical investigations reveal that 2-aminophosphinines are missing links in the series of known 2-donor-functionalized phosphinines. These compounds show high pi-density at the phosphorus atom due to strong interaction with the pi-donating NR2 group.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Inorganic & Nuclear
Quinton J. Bruch, Santanu Malakar, Alan S. Goldman, Alexander J. M. Miller
Summary: This study demonstrates the electrochemical N-2 binding and splitting capabilities of a molybdenum complex, and investigates the reaction pathways and intermediates involved. Electrochemical kinetic analysis, spectroelectrochemical monitoring, and computational studies reveal two concurrent reaction pathways.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Andre K. Eckhardt, Martin-Louis Y. Riu, Peter Muller, Christopher C. Cummins
Summary: In this study, further reactivity studies of the N(3)PA molecule were conducted, including strain-promoted 1,3-dipolar cycloaddition with cyclooctyne and Staudinger-type reactivity. The click reaction was found to be faster than the dissociation of N(3)PA. The Staudinger-type reactivity allowed transfer of the NPA fragment to a base-stabilized silylene.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Benjamin M. Gordon, Nicholas Lease, Thomas J. Emge, Faraj Hasanayn, Alan S. Goldman
Summary: A new bulky triphosphine ligand, ((PPP)-P-tBu)Ir, has been reported to efficiently catalyze the dehydrogenation of alkanes. Compared to traditional ligands, this ligand results in a more crowded spatial arrangement around the metal center, leading to enhanced catalytic activity.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Andre K. Eckhardt, Martin-Louis Y. Riu, Mengshan Ye, Peter Muller, Giovanni Bistoni, Christopher C. Cummins
Summary: A novel phosphorus mononitride precursor is reported, which can release PN molecules in solution and serve as a PN transfer reagent for synthesis.
Article
Chemistry, Inorganic & Nuclear
Benjamin M. Gordon, Ashish Parihar, Faraj Hasanayn, Alan S. Goldman
Summary: The triphosphorus-coordinating pincer iridium fragment ((PPP)-P-tBu)Ir has been found to exhibit high activity for the dehydrogenation of n-alkanes. The use of sterically unhindered hydrogen acceptors can enhance its activity, allowing for appreciable rates even at low temperatures.
Article
Chemistry, Inorganic & Nuclear
Brendon J. McNicholas, Cherish Nie, Anex Jose, Paul H. Oyala, Michael K. Takase, Larry M. Henling, Alexandra T. Barth, Alessio Amaolo, Ryan G. Hadt, Edward I. Solomon, Jay R. Winkler, Harry B. Gray, Emmanuelle Despagnet-Ayoub
Summary: Thirteen boronated cyanometallates and one metalloboratonitrile have been characterized and studied for their electronic structures and redox properties. The results showed that these compounds exhibit highly reversible redox couples and some of them are surprisingly stable.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Quinton J. Bruch, Akira Tanushi, Peter Muller, Alexander T. Radosevich
Summary: This study demonstrates that hydride transfer catalysis can be enabled by a transition metal-bound low symmetry tricoordinate phosphorus ligand. The reactivity of the phosphorus ligand enables catalytic hydrodechlorination, making it a significant finding in the field of catalysis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Inorganic & Nuclear
Santanu Malakar, Benjamin M. Gordon, Souvik Mandal, Thomas J. Emge, Alan S. Goldman
Summary: The reaction between [(p-cymene)RuCl2]2 and the triphosphine ligand bis(2-di-tert-butylphosphinophenyl)phosphine (tBuPHPP) leads to an exchange reaction where a chloride ligand and a phosphorus-bound H atom are exchanged to form the (chlorophosphine)ruthenium hydride complex (tBuPClPP)RuHCl. The thermodynamics of Cl-P/Ru-H exchange depends on the nature of the ancillary ligand. This study has implications for five-coordinate d6 complexes.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Tomoaki Sakurada, Yeongsu Cho, Watcharaphol Paritmongkol, Woo Seok Lee, Ruomeng Wan, Annlin Su, Wenbi Shcherbakov-Wu, Peter Mueller, Heather J. Kulik, William A. Tisdale
Summary: This work reports a chemically robust yellow emissive one-dimensional (1D) semiconductor, silver 2,6-difluorophenylselenolate-AgSePhF2(2,6), which belongs to the class of hybrid low-dimensional semiconductors. Introduction of fluorine atoms at the (2,6) position of the phenyl ring induces a structural transition from 2D sheets to 1D chains. AgSePhF2(2,6) exhibits strongly dispersive conduction and valence bands along the 1D crystal axis. Visible photoluminescence with prompt and delayed components is observed at room temperature.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Faraj Hasanayn, Patrick L. Holland, Alan S. Goldman, Alexander J. M. Miller
Summary: The activation of dinitrogen by coordination to transition metal ions is a widely used and promising approach to the utilization of Earth's most abundant nitrogen source for chemical synthesis. However, there is a lack of consensus on assigning a Lewis structure for bridging N2 complexes, which hinders the understanding and prediction of reactivity trends.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Inorganic & Nuclear
Taryn D. Palluccio, Meaghan E. Germain, Marco Marazzi, Manuel Temprado, Jared S. Silvia, Peter Mueller, Christopher C. Cummins, Jack V. Davis, Leonardo F. Serafim, Burjor Captain, Carl D. Hoff, Elena V. Rybak-Akimova
Summary: This study describes the synthesis and structures of nitrile complexes of V (N[(t) Bu] Ar) (3), 2 (Ar = 3,5-Me2C6H3). The thermochemical and kinetic data for their formation were determined using various techniques. The extent of back-bonding from metal to coordinated nitrile reveals a different role of electron donation compared to the related complex Mo (N[(t) Bu] Ar) (3), 1. Kinetic studies show similar rate constants for nitrile binding to 2, but the activation parameters depend on the nature of R in RCN. Density functional theory (DFT) calculations support the formation of a π-stacking interaction between a pendant arene of the metal anilide and the arene substituent on the incoming nitrile in favorable cases.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Tariq M. Bhatti, Akshai Kumar, Ashish Parihar, Hellan K. Moncy, Thomas J. Emge, Kate M. Waldie, Faraj Hasanayn, Alan S. Goldman
Summary: In this paper, a new pN-pyridyl-based PCP pincer ligand was synthesized and metalated to give an iridium complex. In contrast to its phenyl-based congeners, the iridium complex is highly air-sensitive and reacts with oxidants, leading to the activation of a phosphino-tert-butyl C(sp(3))-H bond and cyclometalation.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Gregory D. Thiabaud, Miriam Schwalm, Sajal Sen, Ali Barandov, Jacob Simon, Peter Harvey, Virginia Spanoudaki, Peter Muller, Jonathan L. Sessler, Alan Jasanoff
Summary: This study successfully synthesized a molecular probe that allows assessment of intracellular calcium levels through fluorescence, photoacoustic, and magnetic resonance imaging techniques, which can be detected in brain tissue.
Article
Materials Science, Multidisciplinary
William J. Mullin, Peter Mueller, Anthony J. Schaefer, Elisa Guzman, Steven E. Wheeler, Samuel W. Thomas
Summary: This study investigates the stacking interactions between aromatic rings and heterocycles, revealing that fluorinated side-chains and electron-rich units have interactions in the solid state, while electron-deficient units are incompatible. These interactions play a significant role in compound stability.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
