Article
Multidisciplinary Sciences
Andre Al-Haddad, Solene Oberli, Jesus Gonzalez-Vazquez, Maximilian Bucher, Gilles Doumy, Phay Ho, Jacek Krzywinski, Thomas J. Lane, Alberto Lutman, Agostino Marinelli, Timothy J. Maxwell, Stefan Moeller, Stephen T. Pratt, Dipanwita Ray, Ron Shepard, Stephen H. Southworth, Alvaro Vazquez-Mayagoitia, Peter Walter, Linda Young, Antonio Picon, Christoph Bostedt
Summary: This study demonstrates the ability to track ultrafast electron rearrangement and chemical bond breaking in real time at specific sites using X-ray photoelectron spectroscopy. By observing the chemical shifts of the carbon core-electron binding energy, the authors can investigate charge redistribution and dissociation processes.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Yasemin Yesiltepe, Niranjan Govind, Thomas O. Metz, Ryan S. Renslow
Summary: The majority of primary and secondary metabolites in nature have yet to be identified, posing a major challenge for metabolomics studies. Complete chemical characterization of metabolomes is currently infeasible due to technical and economic limitations. Computationally predicted data can be a viable solution to expand metabolite reference libraries, but accuracy is crucial. A study using simulated experimental and theoretical NMR chemical shift databases found that a certain level of accuracy is required for confident identification of metabolites in different samples.
JOURNAL OF CHEMINFORMATICS
(2022)
Article
Chemistry, Physical
Ulysse Caniparoli, Imma Escofet, Antonio M. Echavarren
Summary: Planar chiral monodentate 1,3-disubstituted ferrocene phosphines inspired by JohnPhos-type ligands have been synthesized and applied for the enantioselective gold(I) catalyzed [4 + 2] cycloaddition of 1,6-arylenynes. Computational studies elucidated the working mode of the catalyst, involving attractive noncovalent interactions that induce the folding of the substrate in the chiral environment of the ligand.
Article
Chemistry, Multidisciplinary
Qiang Dai, Lu Liu, Junliang Zhang
Summary: This study successfully achieved the kinetic resolution of rac-secondary phosphine oxides via enantioselective P-benzylation catalysis, delivering both tert- and sec-phosphine oxides in good yield and excellent enantiopurity. The synthetic utilities were further demonstrated by the facile preparation of valuable P-chiral compounds, precursors of bidentate ligands, and transition metal complexes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Biochemistry & Molecular Biology
Svetlana A. Kondrashova, Fedor M. Polyancev, Shamil K. Latypov
Summary: This study compares calculated and experimental P-31 NMR shifts for a range of palladium complexes and finds that, overall, the theory reproduces the experimental data well. The only exception is complexes with P=O phosphorus, where there is a systematic underestimation of shielding. The use of specific basis sets and polarization functions can reduce this underestimation. In practice, a simple approximation method is acceptable for rapid assessment of P-31 NMR shifts, except for the P=O type. The study also identifies optimal approaches for price-quality ratio. A linear scaling procedure is necessary in all cases to minimize systematic errors.
Article
Chemistry, Multidisciplinary
Martins Balodis, Manuel Cordova, Albert Hofstetter, Graeme M. Day, Lyndon Emsley
Summary: The determination of the three-dimensional atomic-level structure of powdered solids is an important goal in current chemistry. This study successfully determined the crystal structures of ampicillin, piroxicam, cocaine, and two polymorphs of the drug molecule AZD8329 using machine-learned isotropic chemical shifts generated on-the-fly to guide a Monte Carlo-based structure determination process.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Sonam Maiti, Thorsten Ohlerth, Niclas Schmidt, Stephan Aussen, Rainer Waser, Ulrich Simon, Silvia Karthaeuser
Summary: The research synthesized sub-10 nm HfO2 nanocrystals and used them to build microscale and nanoscale test devices. Electrical characterization revealed redox-like behavior in ambient atmosphere and volatile threshold switching in vacuum.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Inorganic & Nuclear
Md Ashraful Islam, Matthieu Autillo, Laetitia Guerin, Christelle Tamain, Philippe Moisy, Helene Bolvin, Claude Berthon
Summary: This study investigates the nuclear magnetic resonance spectroscopy and magnetic properties of a series of actinide compounds using experimental and computational methods. The experimental evaluation of parameters such as magnetic susceptibility and hyperfine coupling constants reveals a slight decrease in the covalency of uranium series elements.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Enrico Benassi
Summary: This study establishes a protocol for calculating chemical shifts using density functional theory, validated with various functional and basis sets for F-19-NMR. By benchmarking with two sets of molecules, the computational workflow presents a significant improvement in accurately predicting and interpreting chemical shifts.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2022)
Article
Chemistry, Physical
Gaukhar K. Bishimbayeva, Nina K. Gusarova, Arailym M. Nalibayeva, Svetlana I. Verkhoturova, Amangul Bold, Natalya A. Chernysheva, Assem K. Zhangabayeva, Svetlana N. Arbuzova, Yerlan N. Abdikalykov, Dinara S. Zhumabayeva
Summary: This study investigated the synthesis of sulfur-containing organophosphorus compounds using phosphorus, sulfur, and alkyl bromides. The results showed that by reacting non-toxic red phosphorus with alkyl bromides under the conditions of phase transfer catalysts, and then introducing elemental sulfur, the desired alkylphosphine sulfides were obtained. These synthesized mixtures showed highly effective extraction properties for heavy metals and noble metals.
Article
Chemistry, Multidisciplinary
Jonas C. Ott, Elizaveta A. Suturina, Ilya Kuprov, Joscha Nehrkorn, Alexander Schnegg, Markus Enders, Lutz H. Gade
Summary: In this study, experimental observations of P-31 and H-1 NMR resonances shifted by over 10 000 ppm in a square planar ferrous complex were reported. The influence of magnetic anisotropy and zero-field splitting on paramagnetic shift and relaxation enhancement was investigated using various techniques, and spin dynamics simulations showed the possibility of observing NMR signals of directly metal-bonded atoms even with relatively slow electron spin relaxation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Manuel Cordova, Edgar A. Engel, Artur Stefaniuk, Federico Paruzzo, Albert Hofstetter, Michele Ceriotti, Lyndon Emsley
Summary: Nuclear magnetic resonance (NMR) chemical shifts provide information about the atomic environments in solid materials, but accurately predicting these shifts is computationally expensive. ShiftML is a machine-learning model that can rapidly predict chemical shifts with the same accuracy as density functional theory (DFT) calculations, reducing the computational cost by over four orders of magnitude.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Stefan Adrian F. Nastase, Yiru Ye, Teng Li, Sang -Ho Chung, Javier Ruiz-Martinez, Abhishek Dutta Chowdhury, Luigi Cavallo
Summary: Zeolites are widely used and researched in various reaction processes. Understanding the reaction mechanisms involved has been a long-term challenge, but computational simulations analyzing 13C chemical shifts of different compounds have proven useful.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Medicinal
Cristina Cuadrado, Antonio Hernandez Daranas, Ariel M. M. Sarotti
Summary: This study assessed the impact of force field selection, geometry, and energy cutoffs in NMR data prediction for structure elucidation. A new method called mix-J-DP4 was proposed based on the conclusions, which showed a remarkable increase in the confidence level of complex stereochemical assignments with a modest increment in computational cost.
Article
Multidisciplinary Sciences
Manuel Cordova, Martins Balodis, Bruno Simoes de Almeida, Michele Ceriotti, Lyndon Emsley
Summary: This study successfully demonstrates probabilistic chemical shift assignment of organic crystals using a combination of machine learning model and statistical analysis, enabling scientists to assign shifts directly from the structure. The correct assignment was found in over 80% of cases among experimental and predicted shifts.
Review
Chemistry, Multidisciplinary
Leonid B. Krivdin
MAGNETIC RESONANCE IN CHEMISTRY
(2020)
Review
Chemistry, Multidisciplinary
Leonid B. Krivdin
MAGNETIC RESONANCE IN CHEMISTRY
(2020)
Article
Chemistry, Multidisciplinary
Valentin A. Semenov, Leonid B. Krivdin
MAGNETIC RESONANCE IN CHEMISTRY
(2020)
Article
Chemistry, Multidisciplinary
Valentin A. Semenov, Dmitry O. Samultsev, Leonid B. Krivdin
MAGNETIC RESONANCE IN CHEMISTRY
(2020)
Correction
Chemistry, Physical
Valentin A. Semenov, Dmitry O. Samultsev, Leonid B. Krivdin
JOURNAL OF PHYSICAL CHEMISTRY A
(2020)
Review
Chemistry, Multidisciplinary
Leonid B. Krivdin
MAGNETIC RESONANCE IN CHEMISTRY
(2020)
Review
Chemistry, Multidisciplinary
Leonid B. Krivdin
MAGNETIC RESONANCE IN CHEMISTRY
(2020)
Review
Chemistry, Multidisciplinary
Leonid B. Krivdin
RUSSIAN CHEMICAL REVIEWS
(2020)
Article
Chemistry, Multidisciplinary
Valentin A. Semenov, Leonid B. Krivdin
Summary: Based on the calculations of NMR chemical shifts, several spectral reassignments and corrections were made to the H-1 and C-13 NMR spectra of the large trimeric indole alkaloid strychnohexamine. New assignments of diastereotopic protons were made and the chemical shifts of unassigned carbon and protons were predicted.
MAGNETIC RESONANCE IN CHEMISTRY
(2021)
Article
Chemistry, Physical
Valentin A. Semenov, Leonid B. Krivdin
Summary: The PBE0 functional combined with a new triple zeta basis set 3z-S was used for benchmark calculations of C-13 NMR chemical shifts in a variety of natural products, showing good accuracy and high cost-effectiveness compared to larger basis sets. This suggests a prospective use of the 3z-S basis set for C-13 NMR calculations in a wide range of natural products.
INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
(2021)
Review
Chemistry, Multidisciplinary
Leonid B. Krivdin
Summary: This review highlights significant progress in the calculation of Se-77 NMR chemical shifts and spin-spin coupling constants involving selenium, supported by a vast amount of experimental data. The material is organized into two main sections: one focusing on Se-77 NMR chemical shifts and the other on spin-spin coupling constants involving Se-77 nucleus. Special attention is given to the stereoelectronic effects of the selenium atom in the NMR spectra of organoselenium compounds.
RUSSIAN CHEMICAL REVIEWS
(2021)
Article
Biochemistry & Molecular Biology
Valentin A. Semenov, Leonid B. Krivdin
Summary: Succeeding variants of SARS-CoV-2 have increased contagion. Inhibiting the binding of spike protein to the ACE2 receptor is a potential strategy to prevent COVID-19 infection. By using pharmacophore models and induced fit docking, natural compounds that could serve as inhibitors were identified. These findings will stimulate further research and drug development.
Article
Biochemistry & Molecular Biology
Valentin A. Semenov, Leonid B. Krivdin
Summary: H-1 and C-13 NMR chemical shifts of alasmontamine A, a tetracyclic monoterpene indole alkaloid with a molecular formula of C84H91N8O12, were calculated using DFT framework. Six lowest energy conformers and three key configurations contributing to NMR shielding constants were identified. Ambiguities in the reported assignment of NMR chemical shifts of alasmontamine A were resolved.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Chemistry, Inorganic & Nuclear
Dmitry O. O. Samultsev, Valentin A. A. Semenov, Leonid B. B. Krivdin
Summary: The relativistic effects on the shielding constants of various nuclei and their importance in theoretical calculations of chelate complexes were studied. The accuracy factors affecting the calculation of chemical shifts were analyzed. It was found that relativistic effects have a significant impact on the results.
Article
Chemistry, Multidisciplinary
Valentin A. Semenov, Leonid B. Krivdin
Summary: In this study, the H and C NMR chemical shifts of the large dimeric indole alkaloid strychnobaillonine were calculated using the computational protocol PBE0/pcSseg-2//pcseg-2, achieving good results with minimal deviations. Discrepancies between the calculated and experimental NMR spectra allowed for additional assignments and reassignments of the structure proposed originally.
MAGNETIC RESONANCE IN CHEMISTRY
(2021)
