Article
Chemistry, Applied
Yongting Chen, Junxiang Chen, Shengli Chen
Summary: Electrocatalysis plays a crucial role in energy and environmental technologies, and volcano relations are commonly used tools for predicting activity trends. Modern electrocatalytic volcano relations are typically based on kinetic models, but important factors impacting reaction kinetics are often overlooked. Constructing more rational volcano relations is a current research direction in this field.
CHINESE JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Physical
Benjamin W. J. Chen
Summary: In this review, computational methods for predicting kinetic and equilibrium isotope effects in heterogeneous catalysis are discussed. The influence of the catalytic environment and the potential pitfalls in isotope studies are also explored. Possible future applications of isotope effects and the promising synergies between experiments and computations are highlighted throughout the review.
CATALYSIS COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Victor Wambua, Jennifer S. Hirschi, Mathew J. Vetticatt
Summary: This study introduces a practical approach for the rapid determination of C-13 kinetic isotope effects using a designed reactant with two identical reaction sites. By investigating and evaluating the mechanism under different synthetic conditions, it offers an efficient technique for rapidly obtaining high-resolution information regarding the transition structure of synthetically relevant reactions.
Article
Thermodynamics
Huanhuan Wang, Lili Xing, Cheng Xie, Bingzhi Liu, Hong Wang, Zhandong Wang
Summary: This work investigates the H-abstraction reaction, isomerization, and α-dissociation of isopentanol using quantum chemical theory and kinetic methods. The study finds that H-abstraction by H atoms follows the Evans-Polanyi principle, and isomerization dominates at low temperatures while α-C-C bond dissociation dominates at high temperatures.
COMBUSTION AND FLAME
(2022)
Article
Geochemistry & Geophysics
Andrea Ricci, Barbara I. Kleine, Jens Fiebig, Johann Gunnarsson-Robin, Kennedy Mativo Kamunya, Bruce Mountain, Andri Stefansson
Summary: Molecular hydrogen (H2) plays a crucial role in geochemical and biological processes, but the factors controlling its abundance and isotope composition are uncertain. This study investigates hydrothermal fluids from sub-aerial hydrothermal systems and finds that H2 is mainly sourced from the reduction of H2O and controlled by various factors. Additionally, the study reveals that the isotopic composition of deep reservoir fluids is influenced by the source water and the temperature of the hydrothermal reservoir, and isotopic re-equilibration occurs during the ascent of fluids to the surface.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Thermodynamics
Caiyu Yang, Jin-Tao Chen, Xincheng Zhu, Xin Bai, Yang Li, Kiran K. Yalamanchi, S. Mani Sarathy, S. Scott Goldsborough, Song Cheng, Henry J. Curran, Chong-Wen Zhou
Summary: This study systematically investigates the hydrogen atom abstraction by methyl peroxy (CH3OO) radicals in the gasoline/ethanol interacting chemistry. The high-pressure limiting rate constants for various components were calculated, and it was found that the abstraction of allylic hydrogen atoms from 1-hexene is the fastest at low temperatures.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Lotefa Binta Tuli, Alexander M. Mebel, Michael Frenklach
Summary: The bay-capping mechanism on PAH armchair edges and the kinetics of acetylene addition to specific bays have been investigated. The reaction between C20H9 and C2H2 has a low entrance barrier, leading to the formation of capped products at high temperatures. The reactivity of C21H11 depends on the location of the unpaired electron, with the reaction with C2H2 occurring slowly. The site-specific bay-capping reactions have significant effects on PAH growth.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Polymer Science
X. Y. Bai, L. P. Luo, H. Y. Zhou, J. X. Wang
Summary: Three phenolic modified acrylate derivatives were synthesized and characterized. The photopolymerization kinetics and UV curing speed of the modified acrylate were investigated. The modified acrylate showed high UV curing activity and low shrinkage of cured product.
EUROPEAN POLYMER JOURNAL
(2023)
Article
Chemistry, Physical
Ning Dai, Zhipeng Cai, Xu Zhang, Kejian Li
Summary: The effects of magnetic fields ranging from 0 T to 0.13 T on the photochemical reactions between benzophenone and isopropanol were studied. The results showed that increasing the applied magnetic field strength led to an increased production rate of the product and a shortened induction period. A new theoretical model was used to explain the magnetic phenomenon in the initiation process of the radical reaction.
Article
Chemistry, Multidisciplinary
Yilin Guo, Chen Yang, Huiping Li, Lei Zhang, Shuyao Zhou, Xin Zhu, Huanyan Fu, Zhizhou Li, Zhirong Liu, Chuancheng Jia, Zitong Liu, Wenguang Zhu, Fanyang Mo, Deqing Zhang, Xuefeng Guo
Summary: An accurate single-molecule kinetic isotope effect (sm-KIE) has been used to overcome the limitations of conventional ensemble KIE and provide a more accurate and sensitive determination method. This method has demonstrated high detection sensitivity and accuracy in observing the TS structures and multidimensional regulation of Claissen rearrangement.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Thermodynamics
Binod Raj Giri, Tam V. -T. Mai, Thi T. -D. Nguyen, Milan Szori, Lam K. Huynh, Aamir Farooq
Summary: This study provides experimental and theoretical insights into the reaction of 1,4-pentadiene with OH radicals. The results show that the reaction rate is less affected by temperature and pressure, and the addition pathway dominates at low temperatures, with vinyl alcohol and allyl radical being important product channels.
COMBUSTION AND FLAME
(2022)
Article
Chemistry, Analytical
Lan-tian Xing, Zhong-ping Li, Li Xu, Li-wu Li, Yan Liu
Summary: This study presents and tests an easy-to-use and efficient approach for the catalytic pyrolysis of hydrocarbon gas, which allows for precise measurement of hydrogen isotopes. The proposed method significantly reduces the pyrolysis temperature and improves the analytical precision, resulting in an extended lifespan of the catalytic furnace.
Article
Chemistry, Physical
Xiaochong Xue, Mingjun Zhang, Fei Wei, Chaofei Liang, Jie Liang, Jinglin Li, Wenyu Cheng, Ke Deng, Wei Liu
Summary: The development of proton exchange membrane water electrolysis (PEMWE) offers potential for efficient hydrogen isotope separation, although its separation factor is lower than traditional alkaline water electrolysis. This study proposes gold as a promising cathodic catalyst in PEMWE, achieving a high separation factor and comparable electrochemical performance to platinum catalysts. The separation mechanism in PEMWE is explained by the Volmer mechanism for gold, providing an effective strategy for improving hydrogen isotope separation efficiency.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
D. A. Osinkin, D. M. Zakharov, A. V. Khodimchuk, E. P. Antonova, N. M. Bogdanovich, E. V. Gordeev, A. Yu. Suntsov, N. M. Porotnikova
Summary: The complex oxide Sr1.95Fe1.4Ni0.1Mo0.5O6-x-5(Fx), with different values of x, was studied as a potential electrode material for electrochemical devices. The addition of a fluorine-containing precursor increased the unit cell parameter of the synthesized materials. It was confirmed that there were no traces of fluorine in the sintered oxides, and it was suggested that the use of a fluorine-containing precursor could enhance the oxide's functional characteristics.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Geochemistry & Geophysics
Zhengqiang Che, Michael Nightingale, Benjamin M. Tutolo
Summary: The study quantified the reaction rates between Mg-phyllosilicate substrates and supersaturated solutions at different temperatures using 29Si isotopic doping techniques, and demonstrated the applicability of the Principle of Detailed Balance (PDB) to amorphous Mg-phyllosilicate-water reactions, reinforcing the use of TST rate equations for describing Mg-phyllosilicate growth. The results also suggested that the concept of apparent solubility of amorphous Mg-silicate has thermodynamic significance, and highlighted the potential role of mineral crystallinity in mineral growth during diagenesis.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Correction
Chemistry, Physical
David Ferro-Costas, M. Natalia D. S. Cordeiro, Antonio Fernandez-Ramos
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
David Ferro-Costas, M. Natalia D. S. Cordeiro, Antonio Fernandez-Ramos
Summary: The protocol discussed in this work focuses on studying hydrogen abstraction reactions by atomic hydrogen in molecules with multiple conformations. It involves searching and locating equilibrium structures, generating input for hydrogen abstraction transition states, optimizing low-level conformers, evaluating multistructural partition functions, and calculating thermal rate constants with various corrections for tunneling effects. The method is robust and applicable to a wide range of temperatures for studying reactions in molecules containing carbon and oxygen atoms.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Correction
Chemistry, Multidisciplinary
David Ferro-Costas, Irea Mosquera-Lois, Antonio Fernandez-Ramos
JOURNAL OF CHEMINFORMATICS
(2022)
Article
Chemistry, Physical
Maiara Oliveira Passos, Tiago Vinicius Alves
Summary: Thermal rate constants and product branching ratios for the hydrogen abstraction reactions of 2-butanone by H-atom were estimated using the multipath canonical variational theory with small-curvature tunneling (MP-CVT/SCT). The study found that the product distributions strongly depend on recrossing, tunneling, multiple structures, and torsional anharmonicity effects.
CHEMICAL PHYSICS LETTERS
(2022)
Article
Chemistry, Physical
Joel Leita Nascimento, Adalberto S. Lima Junior, Tiago Vinicius Alves
Summary: Thermal rate coefficients for the hydrogen abstraction reactions of prenol were calculated using MP-CVT/SCT method, with correction for multistructural effects. The results show differences in the reactions at different sites and highlight the inadequacy of single-structure approach for studying combustion mechanism. The estimated product distributions provide insights into the inhibition and promotion of autoignition phenomena.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Biochemistry & Molecular Biology
Szymon Zaczek, Agnieszka Dybala-Defratyka
Summary: This study provides mechanistic insights into the biosynthesis of prFMN and reveals the role of key amino acids in the active site. Although purely computational, it extends and complements the knowledge obtained in laboratory experiments.
BIOCHIMICA ET BIOPHYSICA ACTA-GENERAL SUBJECTS
(2022)
Article
Biochemistry & Molecular Biology
Agata Sowinska, Michal Rostkowski, Agnieszka Krzeminska, Tzofia Englman, Faina Gelman, Agnieszka Dybala-Defratyka
Summary: LinB and DhaA are two well-known haloalkane dehalogenases that can convert various halogenated alkanes, including persistent pollutants. This study aimed to investigate the enzymatic dehalogenation of selected dibromo-and bromochloro-ethanes and propanes by LinB and DhaA using a computational approach. The results indicate that generalizations about the enzymatic process involving different ligands are not possible, even if the ligands are structurally similar. Small structural differences, such as changing the halogen substituent, can result in significant changes in the enzymatic process and the rate-limiting step.
ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS
(2023)
Article
Chemistry, Physical
Murillo H. Queiroz, Tiago V. Alves, Roberto Rivelino
Summary: We examined the photoionization pathways of naphthalene, 1-cyanonaphthalene, and 2-cyanonaphthalene in complex with the water dimer to gain insight into the photodissociation process in the interstellar medium (ISM). Using density functional theory (DFT) and time dependent DFT (TD-DFT), we analyzed the bonding pattern, rotational properties, energy complexation, spectra, and ionic trends of possible photoproducts. Our findings suggest that CT excitations occur from localized occupied MOs in the aromatic molecules to mixed unoccupied MOs in the complexes in high-radiation regions of the ISM, favoring cationic aromatic species. The photoabsorption spectra depend on the type of intermolecular interaction and the position of the cyano-functional group in naphthalene, with O-H center dot center dot center dot pi complexes playing a more significant role in the photodissociation of hydrated naphthalene.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Biochemistry & Molecular Biology
Shefali Baweja, Eleonore Antonelli, Safia Hussain, Antonio Fernandez-Ramos, Isabelle Kleiner, Ha Vinh Lam Nguyen, M. Eugenia Sanz
Summary: In this study, the analysis of 4-methyl-2-nitrophenol (4MNP) was conducted using chirped pulse and Fabry-Perot Fourier transform microwave spectroscopy in combination with quantum chemical calculations. The rotational and nuclear quadrupole coupling constants of 4MNP were determined, as well as the barrier to methyl internal rotation. The results provide insights into the interactions of 4MNP with atmospheric molecules and the influence of the electronic environment on methyl internal rotation barrier heights.
Article
Chemistry, Physical
Adalberto Santana Lima Junior, Joel Leitao Nascimento, Daniel Moura, Tiago Vinicius Alves
Summary: The overall thermal rate coefficients for the CH2CO + O (P-3) -> CH2 + CO2 reaction were estimated using the canonical variational theory with multidimensional small-curvature tunneling corrections and multifaceted variable-reaction-coordinate transition state theory. The energies, equilibrium geometries, and harmonic vibrational frequencies were calculated using the M06-2X/aug-cc-pVTZ level of theory. The thermal rate constants showed excellent agreement with experimental data, confirming that the CH2 + CO2 channel is the most favorable pathway. Fitting the total thermal rate coefficients into a modified Arrhenius equation revealed a temperature-dependent activation energy.
COMPUTATIONAL AND THEORETICAL CHEMISTRY
(2023)
Article
Chemistry, Physical
Wenqin Li, Rizalina Tama Saragi, Marcos Juanes, Jean Demaison, Natalja Vogt, Antonio Fernandez-Ramos, Alberto Lesarri
Summary: The equilibrium structure of selenophenol was studied using rotational spectroscopy and high-level quantum mechanical calculations, providing insight into the electronic and structural properties of selenium compounds. Broadband microwave spectra were measured in the 2-8 GHz range using fast-passage techniques, and narrow-band impulse excitation was used for measurements up to 18 GHz.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Luis Guerrero-Mendez, Anxo Lema-Saavedra, Elena Jimenez, Antonio Fernandez-Ramos, Emilio Martinez-Nunez
Summary: Our study utilized the AutoMeKin program to investigate the formation of glycolonitrile in the interstellar medium under low temperatures. We identified several viable formation routes, including radical-radical reactions and a radical-molecule reaction. Among these, the reaction between OH and CH2CN was found to be the most relevant, producing glycolonitrile in a single step. However, it also produces hydrogen isocyanide and formaldehyde. The formation of hydrogen isocyanide and glycolonitrile was found to be efficient in the harsh conditions of the interstellar medium.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Joel Leitao Nascimento, Maiara Oliveira Passos, Tiago Vinicius Alves
Summary: Thermal rate constants for the hydrogen abstraction reaction of methyl pentanoate were calculated using MS-CVT/SCT. The conformational search for the stationary points was performed with a dual-level algorithm, and 244 geometries were found. The truncation of multistructural partition functions was found to have a significant impact on the thermal rate constants, with potential deviations of up to 75% compared to converged theoretical results.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Joel Leitao Nascimento, Tiago Vinicius Alves
Summary: The thermal rate constants for the hydrogen abstraction reactions of methyl butanoate by H radical were estimated using the multistructural canonical variational theory with small-curvature tunneling. The effects of multiple structures and torsional anharmonicity were corrected through the rovibrational partition functions calculated with the multistructural method based on a coupled torsional potential. The activation energy showed a temperature dependence and the product branching ratios indicated a preference for (R alpha) until 500 K, with other reactions becoming relevant above this temperature, especially for (R beta).
Article
Chemistry, Physical
Daniel Gonzalez, Anxo Lema-Saavedra, Sara Espinosa, Emilio Martinez-Nunez, Antonio Fernandez-Ramos, Andre Canosa, Bernabe Ballesteros, Elena Jimenez
Summary: This study experimentally and theoretically investigated the kinetics and product formation of the OH + CH3NH2 reaction. The results showed a drastic increase in reaction rate at lower temperatures and different reaction trends under different pressure conditions. CH3NH was found to be the dominant product at low temperatures, while CH2NH2 was dominant at higher temperatures, with both reaction channels competing at temperatures above 300 K.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
