Article
Chemistry, Multidisciplinary
Oliver Loveday, Jorge Echeverria
Summary: The study explores a novel hydrogen bond where a methyl group, bound to an electropositive atom, acts as the acceptor through its carbon atom. Experimental examples from the Cambridge Structural Database show a trend towards a linear arrangement of interacting groups as the interatomic distance decreases. Computational techniques were used to investigate the strength and nature of the hydrogen bond, revealing charge transfer from a sigma(E-C) bonding orbital of the methyl group to a sigma* antibonding H-Y orbital.
CRYSTAL GROWTH & DESIGN
(2021)
Article
Crystallography
Alakbar Huseynzada, Matteo Mori, Fiorella Meneghetti, Aygun Israyilova, Elif Guney, Koray Sayin, Laurent R. Chiarelli, Mustafa Demiralp, Ulviyya Hasanova, Vagif Abbasov
Summary: In this study, methyl 6-methyl-4-(4-nitrophenyl)-2-oxo-1,2-dihydropyrimidine-5-carboxylate 2 was prepared by the regioselective oxidative dehydrogenation of dihydropyrimidine derivative 1 in the presence of cerium ammonium nitrate. The tautomeric form of compound 2 was determined through single-crystal X-ray diffraction (SC-XRD). Non-covalent interactions and their impact on the crystal structure were analyzed using Hirshfeld surface and enrichment ratio analyses. Furthermore, the antimycotic activity of compounds 1 and 2 against Candida albicans, Aspergillus flavus, and Aspergillus niger was investigated and compared to fluconazole. Computational investigations provided insights into the better activity of compound 2 compared to its synthetic precursor.
Article
Energy & Fuels
Sang-Jun Han, Jung-Ho Wee
Summary: This study investigated the ratio of real chemical and physical CO2 absorption capacity to total absorption capacity in triethanolamine and methyl-diethanolamine aqueous solutions. Physical absorption dominated in the initial absorption period without reaching saturation. A period of chemical absorption dominance was observed, proportional to the amine concentration. Methyl-diethanolamine had a lower dominance ratio compared to triethanolamine, likely due to its faster absorption rate. Upon completion of chemical absorption, physical CO2 absorption resumed until saturation was reached.
Article
Biochemistry & Molecular Biology
Ligang Xu, Yali Wang, Qunyan Li, Suping Cui, Mingxue Tang, Zuoren Nie, Qi Wei
Summary: In this study, a methyl-modified silica layer (MSL) was supported on porous alpha-Al2O3 ceramic membranes for MTBE/water separation. The MSL, formed by the sol-gel reaction and dip-coating method, combined methyl-modified silica species and pre-synthesized mesoporous silica microspheres to create a hydrophobic mesoporous layer. The MSL-supported alpha-Al2O3 ceramic membranes exhibited high separation factor and total flux.
Article
Biochemistry & Molecular Biology
Rodion V. Belosludov, Kirill V. Gets, Ravil K. Zhdanov, Yulia Y. Bozhko, Vladimir R. Belosludov, Li-Jen Chen, Yoshiyuki Kawazoe
Summary: Using molecular dynamics, the behavior of a metastable solution of methane + water was studied for different concentrations at low pressure. The formation of hydrate-like structures was observed at certain concentrations, suggesting a new mechanism of hydrogen-bond network reorganization that leads to hydrate growth. This study reveals the importance of supersaturation and cavity arrangement in the collective process of hydrate formation.
Article
Chemistry, Multidisciplinary
Amal T. Mogharbel, Aisha Hossan, Matokah M. Abualnaja, Enas Aljuhani, Rami Pashameah, Salhah H. Alrefaee, Hana M. Abumelha, Nashwa M. El-Metwaly
Summary: Three novel complexes were synthesized from a thiosemicarbazide derivative and characterized by their chemical structures and properties. The complexes exhibited strong binding to central atoms in an octahedral geometry with the ligand acting as mononegative bidentate or neutral bidentate. The complexes showed high stability and inhibition against bacteria, as well as good interaction with DNA-polymerase proteins.
ARABIAN JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Qiuli Zhang, Zhongyi Ning, Xuelian Li, Xiaogang Ning, Fan Wu, Jun Zhou
Summary: This study investigates the effect of nanoparticles on the CO2 capture performance of 2-Amino-2-methyl-1-propanol (AMP) aqueous solution. It is found that the addition of TiO2 nanoparticles can accelerate the absorption-desorption process, and there exists an optimal solid content. The experimental results demonstrate the good cycling performance of the nanofluid.
Article
Spectroscopy
Qianqian Huang, Eun Hye Lee, Byeong M. Oh, Hye W. Chun, Woosung Lee, Jong H. Kim
Summary: A series of novel copper phthalocyanines with various aminophenoxy groups were designed and synthesized for detecting strong acids. Among them, octa-(diethyl-aminophenoxy)-substituted CuPc 5 showed excellent detection capability for HCl, with high sensitivity and rapid response in versatile conditions. CuPc 5 also demonstrated reusability and great potential for practical detection of HCl and ammonia gas leak. The sensing performance of CuPc 5 was affected by the dissociation constants of the amine groups, steric hindrance of alkyl chains, molar absorption coefficient of CuPc species, and H2O content of the solvent system.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2022)
Article
Chemistry, Physical
Jun Ni, Siyu Shi, Chuanfeng Zhang, Biyun Fang, Xiuyun Wang, Jianxin Lin, Shijing Liang, Bingyu Lin, Lilong Jiang
Summary: The introduction of oxygen functional groups into carbon-supported ruthenium catalysts through HNO3 gas-phase oxidation treatment facilitates the desorption of hydrogen species, enhances the ammonia synthesis activity, and alleviates the negative effects of carbon methanation and hydrogen poisoning.
JOURNAL OF CATALYSIS
(2022)
Article
Biochemical Research Methods
Ranjini Sarkar, Tarun Kumar Kundu
Summary: The article explores the quantum chemical perspective of gas adsorption efficiency on alpha- and beta-PVDF-supported ionic liquid membranes, with beta-PVDF showing better gas affinity and being qualified as a more suitable membrane component. The dispersion-corrected density functional calculations provide detailed insights into the energetic interactions and gas adsorption properties of the PVDF/IL complexes. Gas molecules interact with the membrane components through weak hydrogen bonds, ensuring effective gas adsorption and effective separation of CO2 and H2 from other gases.
JOURNAL OF MOLECULAR GRAPHICS & MODELLING
(2021)
Article
Thermodynamics
Shokouh Sarlak, Peyvand Valeh-E-Sheyda
Summary: The study investigated the effect of adding L-arginine as a potential promoter for conventional MDEA in a T-junction microreactor for CO2 capture. Results showed that increasing arginine concentration from 4 wt% to 12 wt% intensified CO2 absorption efficiency and gas-phase mass transfer coefficient values. This suggests that arginine could be a promising chemical activator in enhancing CO2 absorption in post-combustion CO2 capture processes.
Article
Chemistry, Multidisciplinary
Ralf Meyer, Kai Mueller, Sergej Naumov, Frank Bauer, Dirk Enke
Summary: The adsorption behavior of surface-modified porous silica was investigated using inverse gas chromatography (IGC). The results showed reduced wettability and loss of Lewis acidity after surface modification.
FRONTIERS IN CHEMISTRY
(2023)
Article
Multidisciplinary Sciences
Zaki S. Safi, Nuha Wazzan
Summary: This study investigates the geometries and nuclear magnetic resonance (NMR) chemical shifts of an azo dye compound and its tautomer. The results show that the prediction accuracy is higher for H-1-NMR chemical shifts compared to C-13-NMR chemical shifts. Among the examined methods, B97D and TPSSTPSS are the most accurate, while M06-2X is the least accurate. The use of TZVP basis sets leads to more accurate predictions.
SCIENTIFIC REPORTS
(2022)
Article
Biochemistry & Molecular Biology
Arzu Ozturk Kesebir, Pinar Guller, Ramazan Kalin, Hasan Ozdemir, Omer Irfan Kufrevioglu
Summary: This study identified new inhibitors of the pentose phosphate pathway (PPP) and determined their inhibitory mechanisms through a combination of experimental and computational methods. The results showed that certain compounds exhibited significant inhibition of G6PD and 6PGD, providing a new structural basis for the development of drugs targeting the PPP.
BIOTECHNOLOGY AND APPLIED BIOCHEMISTRY
(2022)
Article
Thermodynamics
Christophe Coquelet, Eric Boonaert, Alain Valtz, Stanley Huang
Summary: The solubility of methanethiol and ethanethiol in an aqueous methyldiethanolamine solution was investigated using a static analytic method. The study found that increasing pressure and acid gas loading can increase the apparent Henry's law constant of the mercaptans.
JOURNAL OF CHEMICAL AND ENGINEERING DATA
(2021)
Article
Chemistry, Multidisciplinary
Serhii Tretiakov, Leon Witteman, Martin Lutz, Marc-Etienne Moret
Summary: By introducing strain, a strained cationic silane [TSMPSiH](+) with unusual acidity was successfully prepared, showing correlations with ring strain, inductive and electrostatic effects. The conjugate base TSMPSi can activate a THF molecule in the presence of CH-acids to generate a highly fluxional alkoxysilane.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(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, 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)
Correction
Chemistry, Multidisciplinary
Piet J. Driest, Jacobus A. W. Jong, Robert Smakman, Marc-Etienne Moret, Marianne C. Verhaar, Wim E. Hennink, Karin G. F. Gerritsen, Cornelus F. van Nostrum
Article
Chemistry, Multidisciplinary
Maria L. G. Sansores-Paredes, Storm van der Voort, Martin Lutz, Marc-Etienne Moret
Summary: Nickelacyclobutanes are reactive intermediates in the reaction of nickel carbenes and olefins, which can selectively decompose into cyclopropanes, metathesis, or beta-hydride elimination pathways depending on the coordination of different coligands. DFT calculations provide insight into the mechanisms of these pathways.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Joel Gubler, Mitar Radic, Yannick Stoeferle, Peter Chen
Summary: Au-catalyzed hydroamination is successful for alkynes but not alkenes. Gas-phase binding energy studies suggest that differences in binding are not responsible for the different chemical behavior. The synthesis and characterization of 2-aminoalkylgold complexes reveal that protonation or alkylation leads to amine elimination, indicating that a non-competitive protodeauration step is responsible for the failure of Au-catalyzed alkene hydroamination.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Raphael J. Oeschger, Raphael Bissig, Peter Chen
Summary: We report an experimental study on a series of heterobimetallic complexes with Pd(II) and Cu(I), Ag(I), or Au(I), accompanied by DFT calculations. The isolable pincer complexes are models for the intermediates and transition state in Sonogashira and Negishi coupling reactions. According to the DFT calculations, only the transition state has the metal centers within bonding distance. We also report a substituted version of a similar heterobimetallic complex, in which competing dissociation limits the strength of the metal-metal bond. Analysis of the structures in different states and the gas phase dissociation experiment suggest that the dispersion-corrected DFT method overestimates the strength of the metal-metal interaction, distorting the computed potential energy surface for transmetalation.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Vladimir Gorbachev, Alexandra Tsybizova, Larisa Miloglyadova, Peter Chen
Summary: This study evaluates the importance of London dispersion in moderately large organic molecules through experimental and theoretical calculations. The results show that London dispersion contributes small but significant effects on the molecular structure. However, when London dispersion operates against other weak noncovalent interactions, composite effects on the structure that are difficult to predict arise.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Dirk J. Schild, Lucie Nurdin, Marc-Etienne Moret, Paul H. Oyala, Jonas C. Peters
Summary: This study reports the generation and low temperature characterization of a terminally bound iron(III) nitride, which is proposed as an intermediate in iron-mediated nitrogen fixation. Electron spin resonance spectroscopy and DFT calculations reveal the electronic structure of this nitride species, with the majority of the spin residing on boron.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Inorganic & Nuclear
Andre Butikofer, Peter Chen
Summary: This study investigated the hydrogenation of acetophenone using sulfonate charge-tagged cyclopentadienone iron complexes, revealing that replacement of the TMS groups in the catalyst can enhance the activity and longevity.
Article
Chemistry, Inorganic & Nuclear
Andre Butikofer, Peter Chen
Summary: The zwitterionic halido cyclopentadienone iron complexes FeX(CO)2-NMe3 (X = Cl, Br, I) were synthesized and characterized. Their catalytic performance in hydrogenation and transfer hydrogenation reactions was evaluated. The relative reactivity order was determined to be Cl < Br < I, reflecting the relative bond strengths of the Fe-X bonds.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Vladimir Gorbachev, Anna Giorgia Nobile, Alexandra Tsybizova, Peter Chen
Summary: Ligand electronic effects have a significant impact in catalysis, and experimental quantification of these effects can provide insights into chemical reactivity. In this study, cryogenic ion vibrational predissociation (CIVP) spectroscopy was used to measure the electronic effects of terpyridine ligands. The results showed that the electronic character and substituents of the ligands influenced the vibrational frequencies of the reporter chromophore.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Serhii Tretiakov, Martin Lutz, Charles James Titus, Frank de Groot, Joscha Nehrkorn, Thomas Lohmiller, Karsten Holldack, Alexander Schnegg, Maxime Francois Xavier Tarrago, Peng Zhang, Shengfa Ye, Dmitry Aleshin, Alexander Pavlov, Valentin Novikov, Marc-Etienne Moret
Summary: High-valent iron species are important intermediates in catalytic oxidation reactions, and their study contributes to the understanding of both biological and synthetic systems. In this study, the redox chemistry of iron complexes with a dianionic tris-skatylmethylphosphonium (TSMP2-) scorpionate ligand was investigated. The results show that the complexes can undergo one-electron oxidation to form octahedral Fe(III) and Fe(IV) compounds, and the Fe(IV) compound has a triplet ground state. Extensive spectroscopic and computational methods were used to analyze its electronic structure.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Alexandra Tsybizova, Lukas Fritsche, Larisa Miloglyadova, Bernhard Kraeutler, Peter Chen
Summary: We studied the structure and properties of aryl corrins derivatives and found that their bond dissociation energies (BDEs) are modulated by the side chains. To evaluate our experimental results, we analyzed the structural properties of aryl cobinamides using CIVP spectroscopy, static DFT, and dynamic BOMD simulations. The results showed that neither static DFT calculations nor dynamic BOMD simulations could accurately reproduce the CIVP spectra for these flexible molecules, indicating the need for more accurate approaches for characterizing their properties and conformations.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Raphael J. Oeschger, Raphael Bissig, Peter Chen
Summary: This study presents an experimental investigation, accompanied by DFT calculations, on heterobimetallic complexes with Pd(II) and Cu(I), Ag(I), or Au(I). The findings suggest that only the transition state has the two metal centers within bonding distance. Additionally, it is found that the dispersion-corrected DFT method used in the study tends to overestimate the strength of the metal-metal interaction, leading to systematic distortion in the computed potential energy surface for transmetalation.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)