Article
Chemistry, Inorganic & Nuclear
Sebastien G. Guillet, Gianmarco Pisano, Soumyadeep Chakrabortty, Bernd H. Mueller, Johannes G. de Vries, Paul C. J. Kamer, Catherine S. J. Cazin, Steven P. Nolan
Summary: An operationally simple and eco-friendly synthetic protocol for [Rh(acac)(CO)(NHC)] complexes is described, with insights into the mechanism provided through operando spectroscopy. The spectroscopic fingerprints of these complexes are correlated to NHCs' electron-donating descriptor values, highlighting a new strategy to evaluate carbenes' electronic properties. An assessment of these complexes in catalytic applications shows promising results in the catalytic hydrogenation of aromatic ketones.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Reshma Kokane, Yann Corre, Erhard Kemnitz, Mohan K. Dongare, Francine Agbossou-Niedercorn, Christophe Michon, Shubhangi B. Umbarkar
Summary: The Pd/MgF2-x(OH)(x) palladium catalyst supported on acidic fluorinated magnesium hydroxide exhibited good catalytic activity in hydrogenation reactions, with the support's acid sites playing a key role in pre-activating N-heterocycle substrates. Additionally, the catalyst showed high recyclability up to 10 times without loss of activity or palladium leaching.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Fuxing Pan, Shangxin Wei, Lukas Guggolz, Armin R. Eulenstein, Frank Tambornino, Stefanie Dehnen
Summary: The study successfully synthesized novel bismuth-rich polyanions using a specific precursor, with bismuth content exceeding common polyatomic species, paving the way for the construction of bismuth-based materials.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Physical
Hongwei Zhang, Lixiang Zhong, Ismail Bin Samsudin, Kazu Okumura, Hui-Ru Tan, Shuzhou Li, Stephan Jaenicke, Gaik-Khuan Chuah
Summary: In this study, stable subnanometric Rh particles were prepared in Mg-doped zeolite Beta based on electrostatic interaction. These particles showed high selectivity in the hydrogenation reaction of phenol, making them important intermediates for Nylon production.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Abbey N. Ragan, Yannick Kraemer, Wang-Yeuk Kong, Supreeth Prasad, Dean J. Tantillo, Cody Ross Pitts
Summary: This study demonstrates the ability of main group elements such as tellurium to undergo reductive elimination of C-F bonds in superacidic media, revealing different modes of C-F bond formation and the generation of Te-IV cations. Utilizing DFT calculations, the mechanisms of the two unique reductive elimination reactions were investigated.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Phil Preikschas, Milivoj Plodinec, Julia Bauer, Ralph Kraehnert, Raoul Naumann d'Alnoncourt, Robert Schloegl, Matthias Driess, Frank Rosowski
Summary: Catalysts tested for reactions exhibit dynamic structural changes that significantly impact product selectivity and reaction rates, especially in the conversion of synthesis gas to ethanol. Understanding and controlling the catalyst morphology is crucial for optimizing catalytic processes.
Article
Multidisciplinary Sciences
Dan Zhao, Xinxin Tian, Dmitry E. Doronkin, Shanlei Han, Vita A. Kondratenko, Jan-Dierk Grunwaldt, Anna Perechodjuk, Thanh Huyen Vuong, Jabor Rabeah, Reinhard Eckelt, Uwe Rodemerck, David Linke, Guiyuan Jiang, Haijun Jiao, Evgenii Kondratenko
Summary: Propane dehydrogenation to propene is an important industrial process, but current commercial catalysts often suffer from toxicity or ecological concerns. A new environmentally friendly catalyst based on ZnO has been developed, showing higher propene productivity and selectivity compared to traditional catalysts.
Article
Chemistry, Physical
Dmitry Gorbunov, Maria Nenasheva, Evgeny Naranov, Anton Maximov, Edward Rosenberg, Eduard Karakhanov
Summary: Non-phosphorous rhodium-containing catalysts were designed and synthesized for the direct conversion of olefins to alcohols via tandem hydroformylation/hydrogenation. The catalytic performance showed high activity, chemoselectivity, and stable hydroformylation yield in at least the first 5 cycles, although there was a decrease in alcohol selectivity. The influence of temperature, reaction time, total pressure, and molar CO/H2 ratio of syngas on oxygenate yields was discussed in the study.
APPLIED CATALYSIS A-GENERAL
(2021)
Article
Chemistry, Physical
Yuhan Jia, Jun Li, Miaofei Huang, Lijun Geng, Hanyu Zhang, Shi-Bo Cheng, Yuanping Yi, Zhixun Luo
Summary: A comprehensive study on the oxidation reactions of Rh-n(+) (n = 3-30) rhodium clusters reveals a size-dependent ladder oxygenation phenomenon, with Rh3,4O4+, Rh5-7O6+, and Rh8-13O8+ clusters dominating the mass distributions. The oxygen binding modes are closely associated with the ladder oxidation, with different clusters exhibiting different binding modes. The findings have implications for the design of cluster-genetic materials.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Inorganic & Nuclear
Alice Johnson, Cameron G. Royle, Claire N. Brodie, Antonio J. Martinez-Martinez, Simon B. Duckett, Andrew S. Weller
Summary: Rhodium-alkene complexes with different alkenes have been studied for their reactivity towards H-2, with only COD showing significant reaction to form a COE complex. The differences in reactivity are attributed to intramolecular alkene-assisted reductive elimination in the COD complex. Further experiments on ethene complex suggest that reductive elimination from a reversibly formed alkyl hydride intermediate is likely rate-limiting and with a high barrier.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Inorganic & Nuclear
Sibylle Friess, Anna Benyak, Alberto Herrera, Ana M. Escalona, Frank W. Heinemann, Jens Langer, Dominik Fehn, Daniel Pividori, Alexander Grasruck, Dominik Munz, Karsten Meyer, Romano Dorta
Summary: The oxidative addition of bromine or iodine to an Ir(I) sulfoxide pincer complex leads to the formation of Ir(IV) tris-bromido or tris-iodido complexes, respectively. The reductive elimination of iodine from the Ir(IV)-iodido complex can be achieved without any traps by coordinating ligands or donor solvents. The addition of I- results in the quick generation of an isostructural tris-iodo Ir(III)-ate complex, which can be easily reoxidized back to the Ir(IV)-iodido complex.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Gabriele Hierlmeier, Paolo Tosatti, Kurt Puentener, Paul J. Chirik
Summary: This study describes the synthesis of phosphino(oxazoline)pyridine-supported molybdenum(0) cycloocta-1,5-diene complexes and their reactions with dihydrogen and arenes. The study found that the site selectivity of arene insertion reactions depended on the size of the substituent, and electron-rich arenes had faster insertion rates. Additionally, through mechanistic studies, the synthesis of enantioenriched cyclohexa-1,3-diene was achieved.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Shunsaku Yasumura, Ken Nagai, Yucheng Qian, Takashi Toyao, Zen Maeno, Ken-ichi Shimizu
Summary: Rh-loaded mordenite zeolite was used as a catalyst for NO reduction using CO + H2O as a H2 source. Operando IR measurements revealed that Rh dicarbonyl species ([Rh(CO)(2)](+)) captured CO in the zeolite, which reacted with H2O to produce H(2)via the water gas shift (WGS) reaction. TPSR measurements showed that the formed H-2 was directly used for NO reduction into NH3. The study also investigated the mechanism of the WGS reaction.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Review
Chemistry, Inorganic & Nuclear
Raquel Puerta-Oteo, Ana Ojeda-Amador, M. Victoria Jimenez, Jesus J. Perez-Torrente
Summary: This article highlights recent developments on the application of transition metal-based zwitterionic complexes in catalysis, including selected zwitterionic catalysts in polymerization reactions and advances in hydrogenation/dehydrogenation reactions related to energy applications.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Inorganic & Nuclear
Paven Kisten, Eric Manoury, Agusti Lledos, Adrian C. Whitwood, Jason M. Lynam, John M. Slattery, Simon B. Duckett, Rinaldo Poli
Summary: The reaction between [IrCl(COD)](2) and dppe in a 1 : 2 ratio was studied under different conditions. The formation of [IrCl(COD)(dppe)], 1, was observed at room temperature without base. In the presence of a strong base, hydride complexes and deprotonation reactions were observed, leading to the formation of various complexes such as [IrH(1,2,5,6-eta(2):eta(2)-COD)(dppe)], [IrH(1-kappa-4,5,6-eta(3)-C8H12)(dppe)], and [IrH(1-kappa-4,5,6-eta(3)-C8H10)(dppe)]. The selectivity and mechanism of these reactions were explained using DFT calculations.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Gabriele Hierlmeier, Paolo Tosatti, Kurt Puentener, Paul J. J. Chirik
Summary: This study reports a new molybdenum ligand for catalyzing the hydrogenation of benzene, which is formed by the coordination of phosphino(imino)pyridine and cyclooctadiene. The experimental results indicate that the ligand can selectively generate cyclohexane catalyst in the presence of benzene, and the formation of the insertion product is a key step.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Editorial Material
Chemistry, Inorganic & Nuclear
Paul J. Chirik
Article
Chemistry, Multidisciplinary
Yingdong Guan, Leixin Miao, Jingyang He, Jinliang Ning, Yangyang Chen, Weiwei Xie, Jianwei Sun, Venkatraman Gopalan, Jun Zhu, Xiaoping Wang, Nasim Alem, Qiang Zhang, Zhiqiang Mao
Summary: Researchers have discovered a new non-centrosymmetric van der Waals semiconductor, Cr0.32Ga0.68Te2.33, which exhibits intrinsic ferromagnetism and could potentially be a candidate for bulk ferrovalley materials.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Lauren N. Mendelsohn, Connor S. MacNeil, Madison R. Esposito, Tyler P. Pabst, David K. Leahy, Ian W. Davies, Paul J. Chirik
Summary: The cobalt-catalyzed asymmetric hydrogenation of indazole-containing enamides relevant to the synthesis of Zavegepant, a CGRP receptor antagonist, which is approved for the treatment of migraines, is described. Both neutral and cationic bis(phosphine)cobalt complexes were efficient precatalysts, providing excellent yield and enantioselectivities for related substrates, with key reactivity differences observed. The hydrogenation of the indazole-containing enamide was successfully scaled up to 20 g.
Article
Chemistry, Applied
Paul J. Chirik, Keary M. Engle, Eric M. Simmons, Steven R. Wisniewski
Summary: Earth-abundant metal (EAM) catalysis has significant impact on the sustainability and cost improvement in the pharmaceutical industry. It replaces precious metals like palladium and utilizes the reactivity of first-row metals to enable more efficient routes to clinical candidates. This article describes the strategy for building these capabilities within the process group, including the development of a reaction screening platform, scalability demonstration, and increasing mechanism understanding.
ORGANIC PROCESS RESEARCH & DEVELOPMENT
(2023)
Article
Chemistry, Inorganic & Nuclear
Boran Lee, Tyler P. Pabst, Gabriele Hierlmeier, Paul J. Chirik
Summary: Cobalt complexes with 2,6-diaminopyridinesubstituted PNP pincer ligand were synthesized and studied. The PNP pincer ligand showed higher rigidity and electron-donating properties compared to the iPrPNP ligand. The coordination sphere of the metal was completed by a fourth ligand, resulting in planar, diamagnetic, four-coordinate complexes. Computational studies indicated that the increased rigidity of the pincer ligand led to a higher barrier for C-H oxidative addition. The reduced reactivity of (iPrPNMeNP)CoMe enabled it to be an efficient precatalyst for alkene hydroboration.
Article
Chemistry, Multidisciplinary
L. Reginald Mills, Francesca Di Mare, David Gygi, Heejun Lee, Eric M. Simmons, Junho Kim, Steven R. Wisniewski, Paul J. Chirik
Summary: The relative rates of the cobalt-catalyzed C(sp(2))-C(sp(3)) Suzuki-Miyaura cross-coupling were evaluated, and it was found that smaller N-alkyl substituents on the phenoxyimine ligand accelerated the reaction. This inspired the design of optimal cobalt catalysts with phenoxyoxazoline and phenoxythiazoline ligands. The catalyst lifetime was improved by adding excess KOMe•B(O-iPr)3, which attenuated alkoxide basicity and prevented demetallation of the ligand.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Gabriele Hierlmeier, Paolo Tosatti, Kurt Puentener, Paul J. Chirik
Summary: This study describes the synthesis of phosphino(oxazoline)pyridine-supported molybdenum(0) cycloocta-1,5-diene complexes and their reactions with dihydrogen and arenes. The study found that the site selectivity of arene insertion reactions depended on the size of the substituent, and electron-rich arenes had faster insertion rates. Additionally, through mechanistic studies, the synthesis of enantioenriched cyclohexa-1,3-diene was achieved.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Qinzhen Li, Yesen Tan, Baoyu Huang, Sha Yang, Jinsong Chai, Xiaoping Wang, Yong Pei, Manzhou Zhu
Summary: By introducing hydride ligands to simplify the research system, the evolution process between a pair of gold nanocluster isomers is completely revealed. A reversible structural isomerization mechanism is found, and the role of hydride ligands in the dynamic behavior of nanoclusters is highlighted.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Tzu-Hao Chiu, Jian-Hong Liao, Ying-Yann Wu, Jie-Ying Chen, Yuan Jang Chen, Xiaoping Wang, Samia Kahlal, Jean-Yves Saillard, C. W. Liu
Summary: Three unknown rhodium/silver alloy nanoclusters with eight electrons, [RhAg21{S2P((OPr)-Pr- n )(2)}(12)] (1), [RhHAg20{S2P((OPr)-Pr- n )(2)}(12)] (2), and [RhH2Ag19{S2P((OPr)-Pr- n )(2)}(12)] (3), were discovered and characterized. Cluster 1 has a regular Rh@Ag-12 icosahedral core, while clusters 2 and 3 have distorted RhH@Ag-12 and RhH2@Ag-12 icosahedral cores respectively. The insertion of one hydride dopant eliminates one capping silver atom on the cluster surface, resulting in the general formula [RhH x @Ag21-x {S2P((OPr)-Pr- n )(2)}(12)] (x = 0-2). Clusters 1-3 exhibit intense emissions in the near-infrared region, with involvement of the encapsulated heterometal's 4d orbitals in the optical processes.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Jonas Ruby Sandemann, Kristoffer Andreas Holm Stockler, Xiaoping Wang, Bryan C. Chakoumakos, Bo Brummerstedt Iversen
Summary: Accurate structural models are crucial for understanding the structure-property relationships in functional materials. This study focuses on the complex crystal structures of spinels and establishes a benchmark crystal structure for defect-free spinel ferrite ZnFe2O4. Various diffraction techniques are used to provide reference data for testing and refining structural models. The results demonstrate the significance of atomic displacement parameters in accurately describing the cation inversion in spinel-type materials.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
L. Reginald Mills, David Gygi, Eric M. Simmons, Steven R. Wisniewski, Junho Kim, Paul J. Chirik
Summary: The mechanism of phenoxyimine (FI)-cobalt-catalyzed C(sp(2))-C(sp(3)) Suzuki-Miyaura cross-coupling was studied using kinetic measurements and catalytic and stoichiometric experiments. Dimeric (FI) cobalt(II) bromide complexes were isolated and characterized, and one complex was used as a single-component precatalyst for the cross-coupling reaction. The involvement of boronate intermediates in transmetalation was confirmed by Hammett studies of aryl boronic esters. A cobalt(II)/cobalt(III) catalytic cycle was proposed that proceeds through a boronate-type mechanism.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Inorganic & Nuclear
Coralie Duchemin, Amelia I. Liu, Junho Kim, Paul J. Chirik
Summary: This study describes the synthesis, characterization, and reactivity of a series of quinoline pyridine(imine) iron dichloride complexes. The complexes were found to be effective catalysts for the hydrovinylation reaction of butadiene with ethylene, showing high selectivity for the hexa-1,4-diene isomer.
Article
Chemistry, Multidisciplinary
Sean F. McWilliams, Brandon Q. Mercado, K. Cory MacLeod, Majed S. Fataftah, Maxime Tarrago, Xiaoping Wang, Eckhard Bill, Shengfa Ye, Patrick L. Holland
Summary: We conducted studies on a dimeric diiron(ii) hydride complex using various techniques, including X-ray and neutron crystallography, Mossbauer spectroscopy, magnetism, DFT, and ab initio calculations. Our findings provide insights into the dynamics and electronic structure changes induced by hydrides. The hydride positions determine the differing iron geometries, which in turn give rise to a coupled ground state with substantial magnetic anisotropy. The ability of hydrides to rapidly modulate the local electronic structure and spin states at metal sites suggests their potential importance in catalysis.
Article
Chemistry, Inorganic & Nuclear
Junho Kim, Yoonsu Park, Paul J. Chirik
Summary: Piano-stool iridium hydride complexes with phenylpyridine ligands are effective in promoting element-hydrogen bond formation using H-2 as a H-atom source. Blue light irradiation enhances the catalyst turnover for iridium-catalyzed hydrogenation of aryloxyl radicals. The reaction involves proton-coupled electron transfer and formation of an iridium compound. Blue light irradiation with H-2 releases a free heterocycle and regenerates the iridium hydride precatalyst, leading to increased turnover.
INORGANIC CHEMISTRY
(2023)
