Article
Multidisciplinary Sciences
Christian Tantardini, Artem R. Oganov
Summary: Electronegativity is a key property of the elements that plays an important role in structural chemistry and solid state chemistry and physics. The widely used thermochemical Pauling scale has drawbacks, leading the authors to propose a new thermochemical scale based on experimental dissociation energies that provides dimensionless values for electronegativity. This new scale corrects the flaws in the Pauling scale and improves the description of chemical bonding and thermochemistry.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Qing Wen, Hao Fu, Zhen-yu Wang, Ying-de Huang, Zhen-jiang He, Cheng Yan, Jing Mao, Kehua Dai, Xia-hui Zhang, Jun-chao Zheng
Summary: This study proposes a strategy of interfacial engineering and in situ etching to address the challenges of zinc dendrites and side reactions in aqueous rechargeable zinc ion batteries. By introducing a zinc l-cysteine functional layer, the hydrophobicity of the zinc anode is improved, corrosion is mitigated, and uniform zinc deposition is guided. In addition, in situ etching of the zinc foil increases the electrochemical surface area and reduces interfacial resistance. The experimental results show that the Cys-Zn-coated zinc anode exhibits excellent cycling and rate performance.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Article
Chemistry, Organic
Kenji Ota, Kazunori Nagao, Hirohisa Ohmiya
Summary: This method synthesizes sterically hindered alpha-hydroxy carbonyl compounds through radical-radical coupling. It allows for the use of primary, secondary, and tertiary aliphatic carboxylic acids to introduce various alkyl substituents onto ketone moieties of alpha-ketocarbonyls under mild reaction conditions.
Article
Chemistry, Inorganic & Nuclear
Matthieu Regnacq, Denis Lesage, Marte S. M. Holmsen, Karinne Miqueu, Didier Bourissou, Yves Gimbert
Summary: In this study, the mechanism of (P,C)-cyclometalated Au(iii) complexes catalyzing the intermolecular hydroarylation of alkynes is confirmed through experimental data and theoretical calculations, as well as energy-resolved mass spectrometry experiments and kinetic modeling. The results support the previously proposed collisional model and provide insights into the application of this model on fragile adducts.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Physical
Jason J. Sorensen, Erick Tieu, Michael D. Morse
Summary: Resonant two-photon ionization spectroscopy was used to observe sharp predissociation thresholds in lanthanide sulfides and selenides, showing that these thresholds coincide with true 0 K bond dissociation energies. Measurements of the 0 K gaseous heat of formation for each molecule, ionization energies, and bond dissociation energies were reported. Trends in bonding for the lanthanide sulfides and selenides were discussed, with transition metal sulfides found to be 15.6% more strongly bound than corresponding selenides.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Alexandra Tsybizova, Christopher Brenig, Christoph Kieninger, Bernhard Kraeutler, Peter Chen
Summary: The study synthesized a new class of organometallic cationic aryl-cobinamides and determined their stereo-structure using NMR spectra. Gas-phase bond dissociation energies of different isomers were measured by ESI-MS threshold CID experiments, revealing significant contributions of non-bonded interactions in aryl-cobinamides.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Olivia L. Garry, Michael Heilmann, Jingjia Chen, Yufan Liang, Xiaheng Zhang, Xiaoshen Ma, Charles S. Yeung, David Jonathan Bennett, David W. C. MacMillan
Summary: Replacing aryl rings with saturated carbocyclic structures is of great interest in drug discovery for improved pharmacokinetic properties. However, the synthesis of 2-substituted BCPs remains challenging and nonmodular. This study presents a generalizable strategy for bridge functionalization and demonstrates a streamlined pathway to diverse 2-substituted BCPs through radical C-H abstraction and metallaphotoredox protocols.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Li Zhang, Jiyao Yan, Dilgam Ahmadli, Zikuan Wang, Tobias Ritter
Summary: Direct C-H fluorination is an efficient strategy to construct aromatic C-F bonds, but the presence of other functional groups and the high energy barrier of C-F bond formation make the transformation challenging. In this study, a new concept for C-H nucleophilic fluorination without the formation of azaarene Meisenheimer intermediates was reported, achieving successful nucleophilic oxidative fluorination of quinolines through an asynchronous concerted F--e(-)-H+ transfer.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Shree S. Sowndarya, Peter C. St John, Robert S. Paton
Summary: The study shows that the long-term stability of organic radicals requires both thermodynamic and kinetic stability, and the molecular descriptors obtained through quantum chemical calculations can help predict the location of long-lived radicals. The radical stability score is an effective metric for evaluating stable radicals, outperforming thermodynamic scales based on bond dissociation enthalpies.
Article
Chemistry, Inorganic & Nuclear
Matthieu Regnacq, Denis Lesage, Marte S. M. Holmsen, Karinne Miqueu, Didier Bourissou, Yves Gimbert
Summary: The study demonstrates the remarkable catalytic ability of (P,C)-cyclometalated Au(iii) complexes in the intermolecular hydroarylation of alkynes. The previous evidence of an outer-sphere mechanism is confirmed through the analysis of experimental data and DFT calculations. The evaluation of critical energies of dissociation of Au(iii) complexes with different substrates using energy-resolved mass spectrometry experiments and kinetic modeling supports the collisional model and its application to particularly fragile adducts.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Yaxin Yang, Wenrui Zheng, Lufei Ren, Xiaofei Xu
Summary: Sulfur ylides are important reagents in organic synthesis due to their unique reactivity. Studying the proton affinity of sulfur ylides and the influence of different substituents on their nucleophilicity is crucial for the synthesis of heterocyclic compounds.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Physical
Eno Paenurk, Peter Chen
Summary: This study explores the comparison of performance between conventional rate models and L-CID model within the RRKM framework, showing that the BDE values obtained with L-CID model are consistent with those from other rate models within expected uncertainty bounds based on analysis of microcanonical rate data and reaction cross-section data.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)
Article
Chemistry, Organic
Tetsuya Sengoku, Haruka Iwama, Takuma Shimotori, Keisuke Fujimoto, Toshiyasu Inuzuka, Koki Matsune, Hidemi Yoda
Summary: In this study, a heavy-metal-free reductive coupling of arylacetylenes with benzothiazole sulfones is proposed. The reactions of alkyl or benzylic benzothiazole sulfones with arylacetylenes are successfully carried out in the presence of Hantzsch esters and K2CO3 under visible-light irradiation, resulting in moderate to good yields of 1,2-disubstituted alkenes, with the Z-isomer as the major product. The utility of this protocol is expanded to a-deuterative coupling, providing the corresponding alkenes with high deuterium incorporation.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Tetsuya Sengoku, Haruka Iwama, Takuma Shimotori, Keisuke Fujimoto, Toshiyasu Inuzuka, Koki Matsune, Hidemi Yoda
Summary: In this study, a heavy-metal-free reductive coupling reaction of arylacetylenes with benzothiazole sulfones is proposed. The reaction of alkyl or benzylic benzothiazole sulfones with arylacetylenes is successfully achieved under visible-light irradiation in the presence of Hantzsch esters and K2CO3, giving moderate to good yields of 1,2-disubstituted alkenes with Z-isomer as the major product. The utility of this method is further expanded to a-deuteration coupling reaction using a deuterated Hantzsch ester, leading to the corresponding alkenes with high deuterium incorporation.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Zhe Zhou, Zachary S. Sales, Daniel J. Pippel, Michael Qian, Connor L. Martin
Summary: We present a photocatalyst-free, diastereoselective decarboxylative alkylation method for (hetero)aryl sulfinimines using redox-active esters under blue light. This mild and efficient protocol demonstrates its utility as a versatile synthetic tool, especially for medicinal chemists.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Applied
Ayan Dasgupta, Sanjukta Pahar, Rasool Babaahmadi, Lukas Gierlichs, Brian F. Yates, Alireza Ariafard, Rebecca L. Melen
Summary: This study reported a selective borane-catalyzed cyclization reaction from the combination of two different diazo compounds to produce N-substituted pyrazoles. The reaction employed catalytic amounts of tris(pentafluorophenyl)borane to yield the products in yields ranging from 59% to 80%. Extensive DFT studies were conducted to interpret the mechanism, revealing two tandem catalytic cycles catalyzed by B(C6F5)3.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Thomas Auth, Christopher J. Stein, Richard A. J. O'Hair, Konrad Koszinowski
Summary: High-valent tetraalkylcuprates(III) and -argentates(III) are key intermediates in copper- and silver-mediated C-C coupling reactions. Through experiments and calculations, it was found that copper complexes predominantly undergo homo-coupling reactions, while silver complexes primarily undergo cross-coupling reactions. The outer-sphere mechanism was proposed to explain the observed cross-coupling reaction of the silver complex.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Rasool Babaahmadi, Ayan Dasgupta, Christopher J. T. Hyland, Brian F. Yates, Rebecca L. Melen, Alireza Ariafard
Summary: Diazo compounds are commonly used as carbene precursors, and the ease of carbene generation depends on the substituents on either side of the diazo functionality. Tris(pentafluorophenyl)borane has been identified as a potential catalyst for carbene transfer reactions. This study reveals that the efficiency of the catalyst is directly influenced by the substituents on the aryl ring and the carbonyl group of the substrate, which allows for intelligent design of similar catalytic reactions.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Physical
Mona Jalali, Farshad Shiri, Alex C. Bissember, Brian F. Yates, Alireza Ariafard
Summary: Density functional theory (DFT) was used to investigate the mechanism of the efficient hydroalkylation of styrene with acetylacetone in the presence of a bismuth catalyst. The results show that the mechanism is fundamentally different from the analogous gold-catalyzed reaction and is characterized by bismuth coordinating to the oxygens of acetylacetone to form a chelated complex. The activation energy for the reaction with bismuth via the enol isomer of acetylacetone is much lower compared to the ketone isomer.
Article
Chemistry, Physical
Kaveh Farshadfar, Andrew J. Tague, Mohammad Talebi, Brain F. Yates, Christopher J. T. Hyland, Alireza Ariafard
Summary: This study utilizes DFT calculations to uncover a mechanism called redox-promoted Bronsted acid activation, which elucidates the mechanistic details of the phenol and cyclohexadiene annulation catalyzed by the AuCl3/AgOTf mixed system. HOTf is identified as the active catalyst in the annulation reactions, produced in situ through the irreversible reduction of gold(III) to gold(I).
Article
Chemistry, Organic
Kaveh Farshadfar, Nina Gunawan, Farshad Shiri, James K. Howard, Andaravaas Patabadige Jude P. Vaas, Alex C. Bissember, Brian F. Yates, Jason A. Smith, Alireza Ariafard
Summary: A new reaction mechanism, termed the periodinane oxyassisted (POA) oxidation mechanism, has been discovered to explain the oxidative dearomatization of pyrroles in acetic acid.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Howard Z. Ma, Allan J. Canty, Richard A. J. O'Hair
Summary: A near thermal two-step catalytic cycle for the selective release of hydrogen from formic acid was revealed. Mononuclear copper hydride anions were found to react with formic acid to yield copper formate anions and H-2. The copper formate anions can decarboxylate to reform the copper hydride, thus closing the catalytic cycle.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Organic
Samuel C. Brydon, Catriona Thomson, Richard A. J. O'Hair, Jonathan M. White
Summary: Gas phase ion-molecule reactions were used to investigate the electronic and steric effects of substituents on kinetics and branching ratios. Electron-withdrawing groups directed attack at carbon rather than selenium, and increased steric bulk on selenium reduced overall reactivity. The reactivity of the iranium ion derived from Se-methylselenocysteine was also investigated.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Yang Yang, Allan J. Canty, Richard A. J. O'Hair
Summary: Multistage mass spectrometry (MSn) experiments were conducted to investigate the extrusion-insertion reactions of a palladium complex. The results showed that the organopalladium cation was formed and reacted with phenylmethylketene to produce an enolate. Further analysis revealed the formation of an acyl complex. However, attempts to develop a palladium-mediated one-pot synthesis of ketones proved challenging due to low yields and side product formation.
AUSTRALIAN JOURNAL OF CHEMISTRY
(2023)
Article
Physics, Atomic, Molecular & Chemical
Le Thao Anh Nguyen, Chris J. Bowen, Laura Burchill, Spencer J. Williams, Richard A. J. O'Hair
Summary: D-Cysteinolic acid (D-CA) is an important metabolite in the biosulfur cycle, while a structural isomer, (R)-3-amino-2-hydroxypropanesulfonate ((R)-AHPS), is less common. Through mass spectrometry and density-functional theory, this study reveals the fragmentation reactions of these two isomers and methods to distinguish them.
INTERNATIONAL JOURNAL OF MASS SPECTROMETRY
(2024)
Article
Chemistry, Inorganic & Nuclear
Howard Z. Ma, Allan J. Canty, Richard A. J. O'Hair
Summary: This study investigates the possibility of selective decarbonylation of formic acid mediated by molybdate anions in a formal catalytic cycle. The results show that dimolybdate anions can effectively catalyze the decomposition of formic acid, yielding carbon monoxide and water.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Yang Yang, Allan J. Canty, Richard A. J. O'Hair
Summary: The gas-phase and solution-phase reactions for the synthesis of N-phenyl-benzamide were investigated. In the gas-phase experiments, only specific organometallic cations were found to react with phenyl isocyanate via insertion. In the solution-phase experiments, the desired product was not formed, instead, biphenyl was obtained.
AUSTRALIAN JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Manjiri Choudhari, Jingjing Xu, Alasdair McKay, Clement Guerrin, Craig Forsyth, Howard Z. Ma, Lars Goerigk, Richard A. J. O'Hair, Antoine Bonnefont, Laurent Ruhlmann, Stephane Aloise, Chris Ritchie
Summary: The metastable trilacunary heteropolyoxomolybdate and ditopic pyridyl bearing diarylethene self-assemble to form a photo-active molecular capsule through a ligand replacement method. The spatial arrangement of the ligands is determined by the surface chemistry of the molecular metal oxide precursor. The study also discovers a photochemical cascade involving rapid photoinduced ring closure and electron transfer.
Article
Chemistry, Inorganic & Nuclear
Kimberly C. Fabijanczuk, Weam A. O. Altalhi, Asma M. O. Aldajani, Allan J. Canty, Scott A. McLuckey, Richard A. J. O'Hair
Summary: In this study, gas-phase reactions between tris-1,10-phenantholine metal dications and tetraphenylborate anions were investigated. The formation of ion-pairs and subsequent organometallic complex formation were observed. DFT calculations confirmed the energy barriers and hydrolysis reactions in accordance with experimental results.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Multidisciplinary
Thomas Auth, Christopher J. Stein, Richard A. J. O'Hair, Konrad Koszinowski
Summary: This study analyzed the different reactivity of high-valent tetraalkylcuprates(III) and -argentates(III) in copper- and silver-mediated C-C coupling reactions through gas-phase fragmentation experiments, quantum-chemical calculations, and kinetic computations, revealing key mechanisms in the process.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)