Viser treff 351-370 av 525

    • Palladium(0)-Catalyzed Cross-Couplings of 2-Bromophosphinine 

      Kostenko, Nataliya; Eriksson, Cecilia; Engqvist, Magnus; Villa Gonzalez, Susana; Bayer, Annette (Journal article; Tidsskriftartikkel; Peer reviewed, 2013-05-21)
      A new Negishi-type cross-coupling of 2-bromophosphinine has been developed. The new method expands the scope of palladium-catalyzed couplings to monobromophosphinines, which have been considered as poor substrates so far. Moreover, aryl-, alkenyl-, and alkynylzinc bromides were found to be effective coupling partners.
    • Pan genome and CRISPR analyses of the bacterial fish pathogen Moritella viscosa 

      Karlsen, Christian; Hjerde, Erik; Klemetsen, Terje; Willassen, Nils Peder (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-20)
      Background: Winter-ulcer Moritella viscosa infections continue to be a significant burden in Atlantic salmon (Salmo salar L.) farming. M. viscosa comprises two main clusters that differ in genetic variation and phenotypes including virulence. Horizontal gene transfer through acquisition and loss of mobile genetic elements (MGEs) is a major driving force of bacterial diversification. To gain insight ...
    • Parameter-Free Extended Edit Distance 

      Muhammad Fuad, Muhammad Marwan (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
      The edit distance is the most famous distance to compute the similarity between two strings of characters. The main drawback of the edit distance is that it is based on local procedures which reflect only a local view of similarity. To remedy this problem we presented in a previous work the extended edit distance, which adds a global view of similarity between two strings. However, the extended edit ...
    • På vei mot en kollegial tilnærming til undervisning – seminarundervisning og pedagogisk opplæring av stipendiater 

      Johansen, Greta Kristine; Beerepoot, Maarten (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-03-19)
      Seminarundervisning har en viktig rolle i realfagsundervisning i høyere utdanning. Læringsaktivitetene i seminarene samsvarer ofte godt med eksamensformen og dermed bidrar seminarundervisning betydelig til <i>constructive alignment</i> (Biggs, 1999) i et emne. Den viktige rollen seminarundervisning har står i sterk kontrast med den begrensede eller fraværende opplæring ...
    • PCMSolver: an Open-Source Library for Solvation Modeling 

      Di Remigio, Roberto; Steindal, Arnfinn Hykkerud; Mozgawa, Krzysztof; Weijo, Ville; Cao, Hui; Frediani, Luca (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-25)
      PCMSolver is an open‐source library for continuum electrostatic solvation. It can be combined with any quantum chemistry code and requires a minimal interface with the host program, greatly reducing programming effort. As input, PCMSolver needs only the molecular geometry to generate the cavity and the expectation value of the molecular electrostatic potential on the cavity surface. It then returns ...
    • The Perfluoro Cage Effect: A Search for Electron-Encapsulating Molecules 

      Ghosh, Abhik; Conradie, Jeanet (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-01-25)
      Quantum chemical calculations have for some time predicted that perfluorinated polyhedral organic molecules should exhibit a low-energy LUMO consisting of the overlapping inward-pointing lobes of the C−F σ* orbitals. Accordingly, these molecules should be able to encapsulate an electron within the interior of their cavities. Inspired by the recent confirmation of this prediction for perfluorocubane, ...
    • Perturbed atoms in molecules and solids:the PATMOS model 

      Røeggen, Inge; Gao, Bin (Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
      A new computational method for electronic-structure studies of molecules and solids is presented. The key element in the new model – denoted the perturbed atoms in molecules and solids model – is the concept of a perturbed atom in a complex. The basic approximation of the new model is unrestricted Hartree Fock (UHF). The UHF orbitals are localized by the Edmiston-Ruedenberg procedure. The perturbed ...
    • Phase transfer catalyzed conjugate addition-initiated ring-closure (CAIRC) reactions with 2-bromo-2-cyclopentenones 

      Yirsaw, Alemayehu Mekonnen; carlson, Rolf (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-05-07)
      When 2-bromo-2-cyclopentenone is treated with various carbon nucleophiles containing active methylenes, it undergoes a conjugate addition initiated-ring closure (CAIRC) reaction. This leads to the formation of carboand heterocyclic compounds in a regioselective fashion with good to high yield. Several bases and phase transfer catalysts were investigated. CsF-Si(OEt)4 as base together with ...
    • Phenol- and resorcinol-appended metallocorroles and their derivatization with fluorous tags 

      Alemayehu, Abraham; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-11-10)
      Boron tribromide-mediated demethylation of rhenium-oxo and gold meso-tris(4-methoxyphenyl)corrole and meso-tris(3,5-dimethoxyphenylcorrole), M[TpOMePC] and M[T(3,5-OMe)PC] (M = ReO, Au), have yielded the corresponding phenol- and resorcinol-appended metallocorroles, M[TpOHPC] and M[T(3,5-OH)PC], in good yields. The latter compounds proved insoluble in dichloromethane and chloroform but soluble in ...
    • 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 ...
    • Photo-transformation trajectories of Nitro-Spiropyran in Hybrid Compounds with [60]Fullerene 

      Pomogaev, Valdimir A; Avramov, Pavel V; Ruud, Kenneth (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-12)
      Photo- and thermo- isomerization trajectories of various conversion pathways between nitro-spiropyran and its <i>trans–trans–cis</i> merocyanine form were produced and the role of nπ* states was investigated along the corresponding potential energy surface calculated using the ωB97XD functional and the cc-pVDZ basis set. The nondissociative nπ* states on the photoisomerization trajectories can switch ...
    • Photophysics of uracil: an explicit time-dependent generating function-based method combining both nonadiabatic and spin-orbit coupling effects 

      Karak, Pijush; Moitra, Torsha; Ruud, Kenneth; Chakrabarti, Swapan (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-14)
      We present a composite framework for calculating the rates of non-radiative deactivation processes, namely internal conversion (IC) and intersystem crossing (ISC), on an equal footing by explicitly computing the non-adiabatic coupling (NAC) and spin–orbit coupling (SOC) constants, respectively. The stationary-state approach uses a time-dependent generating function based on Fermi's golden rule. We ...
    • 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 ...
    • Platinum Corroles 

      Alemayehu, Abraham; Vazquez-Lima, Hugo; Beavers, Christine M.; Gagnon, Kevin J.; Bendix, Jesper; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-06-09)
      Platinum has been inserted into corroles for the first time and three oxidized PtIV(corrole2)ArAr0 complexes have been structurally characterized. The Soret maxima of these complexes exhibit an unusually strong dependence on the meso-aryl substituents on the corrole, indicating aryl - corrole2 charge transfer character in these transitions.
    • Platinum corroles 

      Alemayehu, Abraham; Lima, Hugo Vazquez; Beavers, Christine M.; Gagnon, Kevin J.; Bendix, Jesper; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-06-09)
      Platinum has been inserted into corroles for the first time and three oxidized Pt<sup>IV</sup>(corrole<sup>2-</sup>)ArAr0 complexes have been structurally characterized. The Soret maxima of these complexes exhibit an unusually strong dependence on the meso-aryl substituents on the corrole, indicating aryl - corrole<sup>2-</sup> charge transfer character in these transitions.
    • A polarizable continuum model for molecules at spherical diffuse interfaces 

      Di Remigio, Roberto; Mozgawa, Krzysztof; Cao, Hui; Weijo, Ville; Frediani, Luca (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-03-22)
      We present an extension of the Polarizable Continuum Model (PCM) to simulate solvent effects at diffuse interfaces with spherical symmetry, such as nanodroplets and micelles. We derive the form of the Green’s function for a spatially varying dielectric permittivity with spherical symmetry and exploit the integral equation formalism of the PCM for general dielectric environments to recast the solvation ...
    • Polarizable Density Embedding for Large Biomolecular Systems 

      Reinholdt, Peter; Jørgensen, Frederik Kamper; Kongsted, Jacob; Olsen, Jógvan Magnus Haugaard (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-09-29)
      We present an efficient and robust fragment-based quantum–classical embedding model capable of accurately capturing effects from complex environments such as proteins and nucleic acids. This is realized by combining the molecular fractionation with conjugate caps (MFCC) procedure with the polarizable density embedding (PDE) model at the level of Fock matrix construction. The PDE contributions to the ...
    • A Polymer Magician: Professor Charlotte K. Williams 

      Hopmann, Kathrin Helen (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-28)
      At Organometallics, the Editorial Team has been highlighting a number of scientists that we feel have had a profound impact on the field and perhaps also on ourselves. In this editorial, I wish to introduce another of our Pioneers and Influencers, Professor Charlotte K. Williams from Oxford University. Professor Williams works on three things I love: homogeneous metal catalysts, carbon dioxide, and ...
    • Porphyryne 

      Ghosh, Abhik; Conradie, Jeanet (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-10-25)
      Density functional theory calculations with the B3LYP*-D3 method with large STO-QZ4P basis sets unambiguously predict a singlet ground state for Zn-porphyryne. However, the calculations also predict a low singlet–triplet gap of about 0.4 eV and a high adiabatic electron affinity of 2.4 eV. Accordingly, the reactivity of porphyryne species may be dominated by electron transfer, hydrogen abstraction, ...
    • Potassium [(1S )-1-azido-2-phenylethyl]trifluoridoborate 

      Lejon, Tore; Gorovoy, Alexey Sergeevich; Khrustalev, Victor N. (Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
      The title compound, K+·C8H8BF3N3-, is a salt containing the chiral organic trifluoridoborate anion. The organic anions and potassium cations are tightly bound to each other by the coordination K-F [2.654 (3)-3.102 (3) Å] and K-N [2.951 (4)-3.338 (4) Å] interactions. Thus, the potassium cation adopts a nine-vertex coordination polyhedron, which can be described as a distorted monocapped tetragonal ...