Viser treff 181-200 av 611

    • Demystifying the Origin of Vibrational Coherence Transfer Between the S1 and T1 States of the Pt-pop Complex 

      Karak, Pijush; Ruud, Kenneth; Chakrabarti, Swapan (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-01)
      We demonstrate that spin-vibronic coupling is the most significant mechanism in vibrational coherence transfer (VCT) from the singlet (S<sub>1</sub>) to the triplet (T<sub>1</sub>) state of the [Pt<sub>2</sub>(P<sub>2</sub>O<sub>5</sub>H<sub>2</sub>)<sub>4</sub>]<sup>4–</sup> complex. Our time-dependent correlation function-based study shows that the rate of intersystem crossing (<i>k</i><sub>ISC</sub>) ...
    • Accurate X-ray Absorption Spectra near L- and M-Edges from Relativistic Four-Component Damped Response Time-Dependent Density Functional Theory 

      Konecny, Lukas; Vicha, Jan; Komorovsky, Stanislav; Ruud, Kenneth; Repisky, Michal (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-27)
      The simulation of X-ray absorption spectra requires both scalar and spin–orbit (SO) relativistic effects to be taken into account, particularly near L- and M-edges where the SO splitting of core p and d orbitals dominates. Four-component Dirac–Coulomb Hamiltonian-based linear damped response time-dependent density functional theory (4c-DR-TDDFT) calculates spectra directly for a selected frequency ...
    • Relativity as a Synthesis Design Principle: A Comparative Study of [3 + 2] Cycloaddition of Technetium(VII) and Rhenium(VII) Trioxo Complexes with Olefins 

      Braband, Henrik; Benz, Michael; Spingler, Bernhard; Conradie, Jeanet; Roger, Alberto; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-13)
      The difference in [3 + 2] cycloaddition reactivity between fac- [MO<sub>3</sub>(tacn)]<sup>+</sup> (M = Re, <sup>99</sup>Tc; tacn = 1,4,7-triazacyclononane) complexes has been reexamined with a selection of unsaturated substrates including sodium 4- vinylbenzenesulfonate, norbornene, 2-butyne, and 2-methyl-3-butyn-2-ol (2MByOH). None of the substrates was found to react with the Re cation in water ...
    • Choosing Bad versus Worse: Predictions of Two-Photon-Absorption Strengths Based on Popular Density Functional Approximations 

      Chołuj, Marta; Alam, MD Mehboob; Beerepoot, Maarten; Sitkiewicz, Sebastian P.; Matito, Eduard; Ruud, Kenneth; Zaleśny, Robert (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-01-26)
      We present a benchmark study of density functional approximation (DFA) performances in predicting the two-photon-absorption strengths in π-conjugated molecules containing electron-donating/-accepting moieties. A set of 48 organic molecules is chosen for this purpose, for which the two-photon-absorption (2PA) parameters are evaluated using different DFAs, including BLYP, PBE, B3LYP, PBE0, CAM-B3LYP, ...
    • High natural PHA production from acetate in Cobetia sp. MC34 and Cobetia marina DSM 4741T and in silico analyses of the genus specific PhaC2 polymerase variant 

      Christensen, Mikkel; Jablonski, Piotr; Altermark, Bjørn; Irgum, Knut; Hansen, Hilde (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-20)
      Background: Several members of the bacterial Halomonadacea family are natural producers of polyhydroxyalkanoates (PHA), which are promising materials for use as biodegradable bioplastics. Type-strain species of Cobetia are designated PHA positive, and recent studies have demonstrated relatively high PHA production for a few strains within this genus. Industrially relevant PHA producers may therefore ...
    • Supramolecular coronation of platinum(II) complexes by macrocycles: Structure, relativistic DFT calculations, and biological effects 

      Sojka, Martin; Chyba, Jan; Paul, Shib Shankar; Wawrocka, Karolina; Honigova, Katerina; Cuyacot, Ben Joseph R.; Castro, Abril C.; Vaculovic, Tomas; Marek, Jaromir; Repisky, Michal; Masarik, Michal; Novotny, Jan; Marek, Radek (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-05)
      Platinum-based anticancer drugs are actively developed utilizing lipophilic ligands or drug carriers for the efficient penetration of biomembranes, reduction of side effects, and tumor targeting. We report the development of a supramolecular host–guest system built on cationic platinum(II) compounds bearing ligands anchored in the cavity of the macrocyclic host. The host–guest binding and hydrolysis ...
    • Evaluation of global EMEP MSC-W (rv4.34) WRF (v3.9.1.1) model surface concentrations and wet deposition of reactive N and S with measurements 

      Ge, Yao; Heal, Mathew R; Stevenson, David S.; Wind, Peter; Vieno, Massimo (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-18)
      Atmospheric pollution has many profound effects on human health, ecosystems, and the climate. Of concern are high concentrations and deposition of reactive nitrogen (N<sub>r</sub>) species, especially of reduced N (gaseous NH<sub>3</sub>, particulate NH<sub>4</sub> <sup>+</sup>). Atmospheric chemistry and transport models (ACTMs) are crucial to understanding sources and impacts of N<sub>r</sub> ...
    • Intrinsic Strand-Incision Activity of Human UNG: Implications for Nick Generation in Immunoglobulin Gene Diversification 

      Alexeeva, Marina; Moen, Marivi Nabong; Xu, Xiang Ming; Rasmussen, Anette; Leiros, Ingar; Kirpekar, Finn; Klungland, Arne; Alsøe, Lene; Nilsen, Hilde; Bjelland, Svein (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-22)
      Uracil arises in cellular DNA by cytosine (C) deamination and erroneous replicative incorporation of deoxyuridine monophosphate opposite adenine. The former generates C ! thymine transition mutations if uracil is not removed by uracil-DNA glycosylase (UDG) and replaced by C by the base excision repair (BER) pathway. The primary human UDG is hUNG. During immunoglobulin gene diversification in ...
    • Generalization of Intrinsic Orbitals to Kramers-Paired Quaternion Spinors, Molecular Fragments, and Valence Virtual Spinors 

      Senjean, Bruno; Sen, Souloke; Repisky, Michal; Knizia, Gerald; Visscher, Lucas (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-08)
      Localization of molecular orbitals finds its importance in the representation of chemical bonding (and antibonding) and in the local correlation treatments beyond mean-field approximation. In this paper, we generalize the intrinsic atomic and bonding orbitals [G. Knizia, J. Chem. Theory Comput. 2013, 9, 11, 4834–4843] to relativistic applications using complex and quaternion spinors, as well as to ...
    • Implementation of Relativistic Coupled Cluster Theory for Massively Parallel GPU-Accelerated Computing Architectures 

      Pototschnig, Johann V.; Papadopoulos, Anastasios; Lyakh, Dmitry I.; Repisky, Michal; Halbert, Loïc; Gomes, Andre Severo Pereira; Jensen, Hans Jørgen Aa.; Visscher, Lucas (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-09)
      In this paper, we report reimplementation of the core algorithms of relativistic coupled cluster theory aimed at modern heterogeneous high-performance computational infrastructures. The code is designed for parallel execution on many compute nodes with optional GPU coprocessing, accomplished via the new ExaTENSOR back end. The resulting ExaCorr module is primarily intended for calculations of molecules ...
    • Understanding Hyperporphyrin Spectra: TDDFT Calculations on Diprotonated Tetrakis(p-aminophenyl)porphyrin 

      Conradie, Jeanet; Wamser, Carl C.; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-29)
      A detailed TDDFT study (with all-electron STO-TZ2P basis sets and the COSMO solvation model) has been carried out on the effect of diprotonation on the UV−vis−NIR spectra of free-base tetraphenylporphyrin and tetrakis(p-aminophenyl)porphyrin. The diprotonated forms have been modeled as their bis-formate complexes, i.e., as so-called porphyrin diacids. The dramatic redshift of the Q-band of ...
    • Phylogenetic Revision of the Genus Aliivibrio: Intra- and Inter-Species Variance Among Clusters Suggest a Wider Diversity of Species 

      Klemetsen, Terje; Karlsen, Christian René; Willassen, Nils Peder (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-18)
      Genus Aliivibrio is known to harbor species exhibiting bioluminescence as well as pathogenic behavior affecting the fish farming industry. Current phylogenetic understanding of Aliivibrio has largely remained dormant after reclassification disentangled it from the Vibrio genus in 2007. There is growing evidence of wider diversity, but until now the lack of genomes and selective use of type strains ...
    • Regioselective formylation of rhenium-oxo and gold corroles: Substituent effects on optical spectra and redox potentials 

      Einrem, Rune F.; Jonsson, Einar Torfi; Teat, Simon J.; Settineri, Nicholas S.; Alemayehu, Abraham B.; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-28)
      Vilsmeier–Haack formylation of ReO and Au meso-triarylcorroles over 16–18 hours affords moderate to good yields (47–65%) of the ReO-3-formyl and Au-3,17-diformyl derivatives in a highly regioselective manner. Formylation was found to effect substantial upshifts for redox potentials (especially the reduction potentials) as well as significant to dramatic redshifts for both the Soret and Q bands.
    • Mechanistic Insights into Copper-Catalyzed Carboxylations 

      Obst, Marc; Gevorgyan, Ashot; Bayer, Annette; Hopmann, Kathrin Helen (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-02)
      The copper-NHC-catalyzed carboxylation of organoboranes with CO<sub>2</sub> was investigated using computational and experimental methods. The DFT and DLPNO-CCSD(T) results indicate that nonbenzylic substrates are converted via an inner-sphere carboxylation of an organocopper intermediate, whereas benzylic substrates may simultaneously proceed along both inner- and outer-sphere CO<sub>2</sub> insertion ...
    • Phidianidine A and Synthetic Analogues as Naturally Inspired Marine Antifoulants 

      Labriere, Christophe; Elumalai, Vijayaragavan; Staffansson, Jannie; Cervin, Gunnar; Le Norcy, Tiffany; Denardou, Hugo; Réhel, Karine; Moodie, Lindon W. K.; Hellio, Claire; Pavia, Henrik; Hansen, Jørn H; Svenson, Johan (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-15)
      Stationary and slow-moving marine organisms regularly employ a natural product chemical defense to prevent being colonized by marine micro- and macroorganisms. While these natural antifoulants can be structurally diverse, they often display highly conserved chemistries and physicochemical properties, suggesting a natural marine antifouling pharmacophore. In our current report, we investigate the ...
    • Anti-proliferative activity of a novel tricyclic triterpenoid acid from Commiphora africana resin against four human cancer cell lines 

      Isaksson, Johan; Rylandsholm, Fredrik G.; Bouř, Petr; Svendsen, John Sigurd Mjøen; Brichtová, Eva; Choi, Sng Un; Lee, Sang‑Ho; Jung, Young-Sik; No, Zae Sung; Aasen, Arne Jørgen; Dekebo, Aman; Dinku, Worku (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-17)
      Myrrh, a resin derived from the damaged bark of Commiphora genus, has traditionally been used for treatment of various human diseases, such as amenorrhea, ache, tumors, fever, and stomach pains. In spite of this widespread use of the myrrh in Ethiopia, the pharmacological activity and chemical composition have not been studied in detail. A new tricyclic triterpene acid (3S,4S,14S,7E,17E,21Z)-3, ...
    • Multiwavelets applied to metal–ligand interactions: Energies free from basis set errors 

      Brakestad, Anders; Wind, Peter; Jensen, Stig Rune; Frediani, Luca; Hopmann, Kathrin Helen (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-02)
      Transition metal-catalyzed reactions invariably include steps where ligands associate or dissociate. In order to obtain reliable energies for such reactions, sufficiently large basis sets need to be employed. In this paper, we have used high-precision multiwavelet calculations to compute the metal–ligand association energies for 27 transition metal complexes with common ligands, such as H2, CO, ...
    • Simple, Axial Ligand-Mediated Route to Water-Soluble Iridium Corroles 

      Thomassen, Ivar K.; Rasmussen, Daniel; Einrem, Rune F.; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-15)
      The synthesis and purification of water-soluble porphyrin-type compounds for photodynamic therapy and other medical applications is often a tedious exercise. Here, we have investigated the simple stratagem of adding a water-soluble axial ligand to the standard protocol for iridium insertion into simple meso-triarylcorroles. Early results showed that six-coordinate Ir[TpXPC](dna)2 derivatives, in ...
    • Synthesis of Potential Metallo-β-Lactamase Inhibitors 

      Paulsen, Marianne Hagensen (Master thesis; Mastergradsoppgave, 2012-06-04)
      Oppgaven omhandler syntesen av mulige metallo-beta-lactamaser inhibitorer.
    • Novel DYRK1A Inhibitor Rescues Learning and Memory Deficits in a Mouse Model of Down Syndrome 

      Stensen, Wenche; Rothweiler, Ulli; Engh, Richard Alan; Stasko, Melissa R.; Bederman, Ilya; Costa, Alberto C. S.; Fugelli, Anders; Svendsen, John Sigurd Mjøen (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-17)
      Down syndrome (DS) is a complex genetic disorder associated with substantial physical, cognitive, and behavioral challenges. Due to better treatment options for the physical co-morbidities of DS, the life expectancy of individuals with DS is beginning to approach that of the general population. However, the cognitive deficits seen in individuals with DS still cannot be addressed pharmacologically. ...