Results 51 to 60 of about 7,655,786 (300)

Accelerating reaction rate predictions: a machine learning approach using a novel quantum chemical property for nucleophilic aromatic substitutions

Machine Learning: Science and Technology
Accurately predicting reaction rate coefficients is crucial for various chemical engineering tasks, such as kinetic modeling and drug synthesis planning. Traditional methods like group additivity and rate rules have limitations, prompting the exploration
Lowie Tomme, István Lengyel, Florence H Vermeire, Christian V Stevens, Kevin M Van Geem   +4 more
doaj   +1 more source

Study of Antioxidant Activity and Quantum-chemical Calculations of 2-aminopyrroles

Разработка и регистрация лекарственных средств, 2022
Introduction. Modern therapy defines oxidative stress as one of the key links in the pathogenesis of different diseases, which makes the search for new low molecular weight antioxidants actual [1].
S. S. Zykova, K. L. Gankova, M. V. Shustov, N. M. Igidov, S. S. Borisevich, M. G. Ilyina   +5 more
doaj   +1 more source

Heterotropic regulation and negative homotropic cooperativity

FEBS Open Bio, EarlyView.
We identified a structural module common to some proteins that couple negative cooperativity with heterotropic regulation, two features that rarely coexist. These proteins are ring‐like and present an ordered asymmetry whereby noncontacting subunits are symmetric, and their tertiary structure differs from that of contacting subunits.
Veronica Morea, Francesco Angelucci, Federica Arnesano, Gianmarco Pascarella, Patrizio Di Micco, Andrea Bellelli   +5 more
wiley   +1 more source

Sterically Facilitated Intramolecular Nucleophilic NMe₂ Group Substitution in the Synthesis of Fused Isoxazoles: Theoretical Study

Molecules, 2020
The influence of steric repulsion between the NMe2 group and a second ortho-(peri-)substituent in the series of 1-dimethylaminonaphthalene and N,N-dimethylanilene ortho-oximes on the ease of the NMe2 group’s intramolecular nucleophilic substitution is ...
Alexander S. Antonov, Elena Yu Tupikina, Valerii V. Karpov, Valeriia V. Mulloyarova, Victor G. Bardakov   +4 more
doaj   +1 more source

Correlations between MO Eigenvectors and the Thermochemistry of Simple Organic Molecules, Related to Empirical Bond Additivity Schemes [PDF]

, 2008
A bondingness term is further developed to aid in heat of formation (ΔfHº) calculations for C, N, O and S containing molecules. Bondingness originated from qualitative investigations into the antibonding effect in the occupied MOs of ethane.
Lee, Matthew Colin John
core  

Quantum Chemical Calculations of1JCCCoupling Constants for the Stereochemical Determination of Organic Compounds

, 2013
Quantum chemical calculations of one-bond carboncarbon coupling constants are demonstrated as potential probes for the configurational assignment of organic molecules. The stereochemical analysis of strychnine and its possible stereoisomers is presented
Giuseppe Bifulco, RICCIO, Raffaele, Gary E. Martin, Alexei V. Buevich, BIFULCO, Giuseppe, Raffaele Riccio, R. Thomas Williamson   +6 more
core   +1 more source

Comparative assessment of crystallographic and cryo‐EM models in the Protein Data Bank

FEBS Open Bio, EarlyView.
Raw data obtained by X‐ray crystallography or cryo‐EM result in experimental maps, ultimately fitted by atomic models. Although the physical principles are different, the final results can be viewed, compared, and evaluated in the same way. With cryogenic electron microscopy (cryo‐EM) on track to surpass X‐ray crystallography as the preferred method ...
Alexander Wlodawer, Pawel Rubach, Zbigniew Dauter, Wojciech Dec, Dariusz Brzezinski, Marta Kulik, Wladek Minor, Mariusz Jaskolski   +7 more
wiley   +1 more source

Electronic Properties of Common Psychostimulants in Aqueous Environments

Molecules
We employed advanced quantum chemical methods to investigate the electronic properties of five widely consumed psychostimulants: nicotine, cotinine, caffeine, theophylline, and theobromine.
Roman Boča, Beáta Vranovičová, Juraj Štofko, Cyril Rajnák   +3 more
doaj   +1 more source

Thermodynamic Parameters of Lead Sulfide Crystals in the Cubic Phase

Фізика і хімія твердого тіла, 2015
Geometric and thermodynamic parameters of cubic PbS crystals were obtained using the computer calculations of the thermodynamic parameters within density functional theory method DFT.
B. P. Volochanska
doaj   +1 more source

jc14269/Dataset-Multilevel-quantum-mechanical-calculations: Dataset-Multilevel-quantum-mechanical-calculations

, 2023
<p>This release contains a dataset of structures used in multilevel quantum calculations for the methanol to dimethyl ether reaction. This hybrid method combines density functional theory, with dispersion corrections (DFT-D3), for the full periodic
jc14269
core   +1 more source