Article
Chemistry, Physical
Reed Nieman, Jhonatas R. Carvalho, Bhumika Jayee, Andreas Hansen, Adelia J. A. Aquino, Miklos Kertesz, Hans Lischka
Summary: The biradical character is an important descriptor for assessing the opto-electronic properties of PAHs. In this study, the unpaired electron densities and NU values calculated using the MR-AQCC method were used to develop a test set for evaluating different biradical descriptors based on density functional theory. The results showed good agreement between the unpaired density and FOD analysis, demonstrating the effectiveness of the method. A new regression relation for determining the finite temperature value was also proposed, improving the assessment of the biradical character of PAHs.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Jochen A. Kammerer, Florian Feist, Daniel Ryklin, Abhishek Sarkar, Christopher Barner-Kowollik, Rasmus R. Schroder
Summary: It is shown that the postfunctionalization of solid polymeric microspheres can produce fully and extensively functionalized materials instead of core-shell structures. The complete functionalization is exemplified by photochemically generated microspheres, which are subsequently converted into polyradical systems. By directly visualizing the chemical distribution inside the postfunctionalized microspheres using characteristic electron energy loss signals in transmission electron microscopy (TEM), this study pioneers characterization methods with high sensitivity and resolution for all-organic low-contrast soft-matter material structures. The successful combination of ultrasonic ultramicrotomy and electron energy loss spectroscopy (EELS) and electron spectroscopic imaging (ESI) in TEM opens up a new avenue for analyzing such structures.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Zehao Gong, Qiang Yan
Summary: A new category of supramolecular hydrogel system held by multiple radical-radical interactions is reported, with photosensitive cross-linking structure. The mechanical performance of the resulting hydrogel materials can be regulated by temporal control of light irradiation, and the reversible collapse of the hydrogels can be promoted by adding radical scavenger or exerting reduction voltage.
CHINESE CHEMICAL LETTERS
(2023)
Article
Mathematics
Stefano Innamorati, Fulvio Zuanni
Summary: In this paper, we investigate the relationship between the incidence numbers of the Hermitian plane and the Hermitian solid, showing that the Hermitian plane incidence numbers can imply the Hermitian solid incidence numbers, except for a few possible small cases.
Article
Environmental Sciences
Baskaran Maheswaran, Natchimuthu Karmegam, Mysoon Al-Ansari, Ramasamy Subbaiya, Latifah Al-Humaid, Joseph Sebastin Raj, Muthusamy Govarthanan
Summary: The study aimed to isolate, quantify, and characterize microplastic pollutants in sediment samples from Kaveri River, South India. Four forms of microplastics were observed, and their composition and distribution were independent of natural substrates. The analysis of microplastics in river sediments can help assess contamination levels and contribute to the formulation of regulations for reducing microplastic pollution.
Article
Polymer Science
Shamsuddeen A. Ahmad, A. L. Lewis, G. Parkes, Y. Tang, L. J. Waters
Summary: This study focuses on the analysis and characterisation of water content and drug-bead interactions in polyvinylalcohol (PVA) hydrogel polymer beads. It confirms the capability of TGA and DSC to characterise different types of water within the beads and indicates relative changes in water content in the presence of drugs. The findings have significant implications for understanding drug loading and release in cancer treatment.
Article
Chemistry, Multidisciplinary
Kalyan Biswas, Jose I. Urgel, M. R. Ajayakumar, Ji Ma, Ana Sanchez-Grande, Shayan Edalatmanesh, Koen Lauwaet, Pingo Mutombo, Jose M. Gallego, Rodolfo Miranda, Pavel Jelinek, Xinliang Feng, David Ecija
Summary: This study reports the successful on-surface synthesis of the largest pristine member of the n-PA family, peri-heptacene, on an Au(111) substrate under ultra-high vacuum conditions. High-resolution scanning tunneling microscopy and theoretical simulations provide insights into the chemical structure of this previously elusive compound. Scanning tunneling spectroscopy reveals that peri-heptacene exhibits an antiferromagnetic open-shell singlet ground state and a singlet-triplet spin-flip inelastic excitation with an effective exchange coupling of 49 meV.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Environmental Sciences
Mailie Saint-Hilaire, Aurore Fourcot, Alain Bousquet-Melou, Guido Rychen, Jean-Pierre Thome, Julien Parinet, Cyril Feidt, Agnes Fournier
Summary: The study found that the major route of excretion for chlordecone in contaminated ewes is through feces, accounting for 86% of the administered dose, with 51% as chlordecone and 35% as chlordecol.
ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY
(2021)
Article
Mechanics
Ahmed A. Shabana, Hao Ling
Summary: This study proposes a new approach for characterizing and quantifying spiral transitions in railroad vehicle system algorithms. The study defines super-elevation and balance speed to better understand their variations in the spiral segment curve. The study develops curve equations using Euler angles used by the rail industry to describe track geometry, and uses the fact that the Frenet bank angle cannot be treated as an independent geometric parameter to accurately quantify spiral-intersection discontinuities. The study highlights the need for adjustments used by rail engineers to achieve smoother spiral intersections.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2022)
Article
Environmental Sciences
Matthieu Dreillard, Caroline De Faria Barros, Virgile Rouchon, Coralie Emonnot, Veronique Lefebvre, Maxime Moreaud, Denis Guillaume, Fabrice Rimbault, Frederic Pagerey
Summary: This study proposes a new analytical protocol to quantify and characterize textile microfibers in terms of their number and size. The study found that the majority of microfibers in washing machine effluents have a length between 50 and 200 μm, with average diameters ranging from 8 to 17 μm. The emission range of microfibers was estimated to be between 220,000 to 2,820,000 microfibers per kg of textile, depending on the type of garment and the washing conditions.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Review
Biochemistry & Molecular Biology
Jeremy Lamarche, Luisa Ronga, Joanna Szpunar, Ryszard Lobinski
Summary: SELENOP as an emerging marker for selenium nutritional status and various diseases still requires further investigation on its chemical characteristics and improvement in accurate quantitation methods; the presence of multiple isoforms and post-translationally modified variants of SELENOP poses challenges for accurate quantification; mass spectrometry techniques offer many advantages and complementary features in the characterization and quantification of SELENOP and should be carefully evaluated.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Biochemistry & Molecular Biology
Amarjeet Yadav, Manish Kumar Tiwari, Deep Kumar, Devesh Kumar
Summary: The study analyzed the reaction mechanism of polycyclic aromatic hydrocarbon polyradicals with hydroxyl and peroxyl radicals, showing that polyradicals can efficiently scavenge these radicals. It was also found that hydroxyl radicals bind more strongly to the edges of polyradicals. Polyradicals have potential applications in preventing damage caused by peroxyl radicals.
JOURNAL OF MOLECULAR MODELING
(2021)
Article
Chemistry, Physical
Vladimir Minkin, Andrey G. Starikov, Alyona A. Starikova
Summary: Computational studies have shown that zethrenes with octacene and nonacene linkers, as well as bisphenalenyls with heptacene, octacene, and nonacene linker groups, exhibit tetraradicaloid nature, making them potential building blocks for organic optoelectronic and spintronic devices characterized by the presence of two types of paramagnetic centers.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)
Article
Plant Sciences
Ze Tian, Jiadi Han, Gen Che, Agula Hasi
Summary: We identified 66 melon SAUR genes, with CmSAUR19, 38, 58, 62 specifically expressed in different stages of fruit growth. These genes may play a role in regulating fruit development.
Article
Mathematics
Michael Gintz, Matthew Kortje, Megan Laurence, Yang Liu, Zili Wang, Yong Yang
Summary: In this paper, we prove that the set of codegrees of M-11, M-12, M-22, M-23, and PSL(3, 3) can determine the isomorphism of these groups.
COMMUNICATIONS IN ALGEBRA
(2022)
Article
Chemistry, Multidisciplinary
Pedro Salvador, Eva Vos, Ines Corral, Diego M. Andrada
Summary: This article discusses the classification of chemical bonds, pointing out that the traditional categorization of electron-sharing or donor-acceptor/dative bonds may not be accurate enough to describe the bonding properties of certain systems. A third possibility is proposed: spin polarized bonds, illustrated by the case of a NaBH3- cluster. Furthermore, a simple model based on bond order and local spin indicators is provided to distinguish between all three bonding situations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Pedro Salvador, Istvan Mayer
Summary: The study introduces a new method based on the chemical Hamiltonian approach, which reduces basis set superposition error. Comparing with previous methods, it shows a significant simplification, but performs poorly with the aug-cc-pVDZ basis set.
INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
(2022)
Article
Chemistry, Physical
Marti Gimferrer, Abdulrahman Aldossary, Pedro Salvador, Martin Head-Gordon
Summary: This study introduces a new method called oxidation state localized orbitals (OSLO) for assigning oxidation states in molecules and evaluating the fragment orbital localization index (FOLI) using an algorithm. The OSLO approach produces satisfactory results in challenging cases and provides new evidence for the emergence of covalent interactions between fragments.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Chemistry, Physical
Mireia Via-Nadal, Mauricio Rodriguez-Mayorga, Eloy Ramos-Cordoba, Eduard Matito
Summary: This paper presents a natural separation method for the Coulomb hole into two components and explains its application in capturing electron correlation. By studying different molecules and atoms, it is found that the components of the Coulomb hole can help identify different correlation regimes.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Enric Sabater, Miquel Sola, Pedro Salvador, Diego M. Andrada
Summary: The classic dichotomy between nitrogen and its heavier congeners is discussed in the context of encapsulation of phosphorus compounds in fullerene cages. Computational studies show that fullerene structures C-70 to C-100 can encapsulate P-2 molecules with intact triple bonds, excluding P-4. Thermodynamic analysis confirms the favorable nature of the encapsulation process.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Marti Gimferrer, Nicolas Joly, Silvia Escayola, Eduard Vinas, Sylvain Gaillard, Miquel Sola, Jean-Luc Renaud, Pedro Salvador, Albert Poater
Summary: In this study, the reductive amination catalyzed by a Knolker-type iron complex was investigated using DFT calculations and chemical structure analysis. It was found that introducing electron-withdrawing substituents on the cyclopentadienone ring of the catalyst can enhance the catalytic efficiency.
Letter
Chemistry, Multidisciplinary
Irene Casademont-Reig, Luis Soriano-Agueda, Eloy Ramos-Cordoba, Miquel Torrent-Sucarrat, Eduard Matito
Summary: This article challenges our conclusions on the aromaticity of a six-porphyrin nanoring linked by a butadiyne, based on experimental H-1-NMR data and calculations using the BLYP35 functional. The authors caution against relying solely on BLYP35 and argue that the indirect evidence of ring current from experimental H-1-NMR data is not a definitive proof of aromaticity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Sebastian P. Sitkiewicz, Robert Zalesny, Eloy Ramos-Cordoba, Josep M. Luis, Eduard Matito
Summary: This study reveals that properties of molecules with low-frequency modes calculated using density functional approximations (DFAs) are affected by spurious oscillations along the nuclear displacement coordinate due to numerical integration errors. By utilizing Fourier spectral analysis and digital signal processing techniques, the error caused by these oscillations is identified and quantified for 45 commonly used DFAs. LC-BLYP and BH&H are found to be the only functionals that show robustness against these spurious oscillations.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Inorganic & Nuclear
Lorena Capdevila, Marc Montilla, Oriol Planas, Artur Brotons, Pedro Salvador, Vlad Martin-Diaconescu, Teodor Parella, Josep M. Luis, Xavi Ribas
Summary: Cobalt-catalyzed C-H amination is a research topic of great interest. Through experimental and computational studies, we have successfully unraveled the mechanism and identified the essential role of carboxylate ligands in stabilizing and guiding the reaction towards C-sp2-N bond formation.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Xabier Telleria-Allika, Jesus M. Ugalde, Eduard Matito, Eloy Ramos-Cordoba, Mauricio Rodriguez-Mayorga, Xabier Lopez
Summary: In this study, the singlet and triplet spin state energies for three-dimensional Hooke atoms, specifically with an even number of electrons, were investigated using Full-CI and CASSCF wavefunctions and various basis sets. The screening effect of electron-electron interaction was also examined using a Yukawa-type potential. The results reveal that the ground state is a singlet for two and eight electron Hooke atoms, while it is a triplet for 4, 6, and 10-electron systems. This study provides insights into the energy components and effects of confinement and electron-electron interaction.
INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Edinson Medina, Christian Sandoval-Pauker, Pedro Salvador, Balazs Pinter
Summary: The electronic structures of 12 different photoredox catalysts involved in oxidative and reductive quenching cycles are characterized using effective oxidation state (EOS) analysis. The results are in agreement with the commonly assumed formal oxidation state assignments. Further analysis reveals separate ligand- and metal-centered redox events and high degree localization of ligand-centered redox event in heteroleptic complexes.
INORGANIC CHEMISTRY
(2022)
Editorial Material
Chemistry, Multidisciplinary
Marti Gimferrer, Sergi Danes, Eva Vos, Cem B. Yildiz, Ines Corral, Anukul Jana, Pedro Salvador, Diego M. Andrada
Summary: In a recent article, Pan and Frenking challenged our assignment of the oxidation state of low valent group 2 compounds. In our reply, we demonstrate that our assignment of Be(+2) and Mg(+2) oxidation states in Be(cAAC(Dip))(2) and Mg(cAAC(Dip))(2) is consistent with our data and provide numerical proof to refute some of the arguments made by Pan and Frenking. We also argue that indicators based on natural orbitals for chemical valence (NOCV) are more reliable than the criterion of the lowest orbital interaction energy in the energy decomposition analysis (EDA) method.
Article
Chemistry, Physical
Abdulrahman Aldossary, Marti Gimferrer, Yuezhi Mao, Hongxia Hao, Akshaya K. Das, Pedro Salvador, Teresa Head-Gordon, Martin Head-Gordon
Summary: Computational quantum chemistry becomes more than just numerical experiments when methods are tailored to explore chemical concepts. Energy decomposition analysis (EDA) is an important example, providing insights into the driving forces behind intermolecular interactions. The newly developed force decomposition analysis (FDA) complements EDA for understanding chemistry and offers more information for data analysis and force field training. By applying FDA, we analyze water interactions with sodium, chloride ions, and the water dimer, as well as the forces responsible for geometric changes of carbon dioxide adsorbed onto gold and silver anions.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Multidisciplinary
Maria Drosou, Gerard Comas-Vila, Frank Neese, Pedro Salvador, Dimitrios A. . Pantazis
Summary: Recent advancements in serial femtosecond crystallography have provided geometric models of distinct intermediates in the catalytic S-state cycle of the oxygen-evolving complex (OEC). However, the interpretation of these models is controversial due to discrepancies in the Mn4CaO5 cluster of the OEC.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Marti Gimferrer, Sergi Danes, Eva Vos, Cem B. Yildiz, Ines Corral, Anukul Jana, Pedro Salvador, Diego M. Andrada
Summary: This article discusses the electronic structure of Lewis base-stabilized Be and Mg compounds and provides an explanation for their proposed oxidation states. The experimentally accomplished compounds rely on increasing the π-acidity of the ligand to strengthen the chemical bonds, and it is suggested that avoiding this interaction could lead to the presence of low-oxidation states.
