Recent additions

  • Origin-independent two-photon circular dichroism calculations in coupled cluster theory 

    Friese, Daniel Henrik; Hättig, Christof; Rizzo, Antonio (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-05-03)
    We present the first origin-independent approach for the treatment of two-photon circular dichroism (TPCD) using coupled cluster methods. The approach is assessed concerning its behavior on the choice of the basis set and different coupled cluster methods. We also provide a comparison of results from CC2 with those from density functional theory using the CAM-B3LYP functional. Concerning the basis ...
  • 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.
  • The three Endonuclease III variants of Deinococcus radiodurans possess distinct and complementary DNA repair activities 

    Sarre, Aili; Stelter, Meike; Rollo, Filipe; De Bonis, Salvatore; Seck, Anna; Hognon, Cecilia; Ravanat, Jean-Luc; Monari, Antonio; Dehez, Francois; Moe, Elin; Timmins, Joanna (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-03-28)
    Endonuclease III (EndoIII) is a bifunctional DNA glycosylase that removes oxidized pyrimidines from DNA. The genome of Deinococcus radiodurans encodes for an unusually high number of DNA glycosylases, including three EndoIII enzymes (drEndoIII1-3). Here, we compare the properties of these enzymes to those of their well-studied homologues from E. coli and human. Our biochemical and mutational data, ...
  • Lactoferricin-inspired peptide AMC-109 augments the effect of ciprofloxacin against Pseudomonas aeruginosa biofilm in chronic murine wounds 

    Laulund, Anne Sofie; Schwartz, Franziska Angelika; Christophersen, Lars; Høiby, Niels; Svendsen, John Sigurd Mjøen; Stensen, Wenche Gunvor Berg; Thomsen, Kim; Cavanagh, Jorunn Pauline; Moser, Claus (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-23)
    Objectives: Chronic wounds are characterised by prolonged inflammation, low mitogenic activity, high protease/low inhibitor activity, microbiota changes and biofilm formation, combined with the aetiology of the original insult. One strategy to promote healing is to terminate the parasitism-like relationship between the biofilm-growing pathogen and host response. Antimicrobial peptide AMC-109 is a ...
  • Identification and Cross-Characterisation of Artificial Promoters and 5′ Untranslated Regions in Vibrio natriegens 

    Tietze, Lisa; Hoff, Maria Wilhelmsen; Lale, Rahmi (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-01-27)
    Vibrio natriegens has recently gained attention as a novel fast-growing bacterium in synthetic biology applications. Currently, a limited set of genetic elements optimised for Escherichia coli are used in V. natriegens due to the lack of DNA parts characterised in this novel host. In this study, we report the identification and cross-characterisation of artificial promoters and 5′ untranslated ...
  • NMR absolute shielding scale and nuclear magnetic dipole moment of 207 Pb 

    Adrjan, Bożena; Makulski, Włodzimierz; Jackowski, Karol; Demissie, Taye Beyene; Ruud, Kenneth; Antušek, Andrej; Jaszuński, Michał (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-05-24)
    An absolute shielding scale is proposed for <sup>207</sup>Pb nuclear magnetic resonance (NMR) spectroscopy. It is based on ab initio calculations performed on an isolated tetramethyllead Pb(CH<sub>3</sub>)<sub>4</sub> molecule and the assignment of the experimental resonance frequency from the gas-phase NMR spectra of Pb(CH<sub>3</sub>)<sub>4</sub>, extrapolated to zero density of the buffer gas to ...
  • Synthetic analogs of stryphnusin isolated from the marine sponge Stryphnus fortis inhibit acetylcholinesterase with no effect on muscle function or neuromuscular transmission 

    Moodie, Lindon; Zuzek, Monika; Frangez, Robert; Andersen, Jeanette hammer; Hansen, Espen; Olsen, Elisabeth Klungerbo; Cergolj, Marija; Sepcic, Kristina; Hanssen, Kine Østnes; Svenson, Johan (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-11-09)
    The marine secondary metabolite stryphnusin (1) was isolated from the boreal sponge Stryphnus fortis, collected off the Norwegian coast. Given its resemblance to other natural acetylcholinesterase antagonists, it was evaluated against electric eel acetylcholinesterase and displayed inhibitory activity. A library of twelve synthetic phenethylamine analogs, 2a–7a and 2b–7b, containing tertiary and ...
  • Relativistic DFT Calculations of Hyperfine Coupling Constants in 5d Hexafluorido Complexes: [ReF6]2- and [IrF6]2- 

    Haase, Pi A. B.; Repisky, Michal; Komorovsky, Stanislav; Bendix, Jesper; Sauer, Stephan P. A. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-10-12)
    The performance of relativistic density functional theory (DFT) methods has been investigated for the calculation of the recently measured hyperfine coupling constants of hexafluorido complexes [ReF<sub>6</sub> ] <sup>2-</sup> and [IrF<sub>6</sub> ] <sup>2-</sup> . Three relativistic methods were employed at the DFT level of theory: the 2-component zeroth-order regular approximation ...
  • Osmium-nitrido corroles as NIR indicators for oxygen sensors and triplet sensitizers for organic upconversion and singlet oxygen generation 

    Borisov, Sergey M.; Alemayehu, Abraham; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-05-26)
    The photophysical properties of nitridoosmium(VI) corroles have been investigated. The complexes exhibit room temperature NIR phosphorescence (l<sub>max</sub> 779–795 nm). Long decay times (110–150 ms in solution and 136–183 ms in polystyrene) are responsible for efficient quenching of the emission by oxygen. All the complexes act as efficient sensitizers of singlet oxygen (quantum yields of ...
  • Synergy between Experimental and Computational Approaches to Homogeneous Photoredox Catalysis 

    Demissie, Taye Beyene; Hansen, Jørn H (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-06-03)
    In this Frontiers article, we highlight how state-of-the-art density functional theory calculations can contribute to the field of homogeneous photoredox catalysis. We discuss challenges in the fields and potential solutions to be found at the interface between theory and experiment. The exciting opportunities and insights that can arise through such an interdisciplinary approach are highlighted.
  • Solvatofluorochromic, non-centrosymmetric π-expanded diketopyrrolopyrrole 

    Grzybowski, Marek; Jeżewski, Artur; Deperasinska, Irena; Friese, Daniel Henrik; Banasiewicz, Marzena; Hugues, Vincent; Kozankiewicz, Bolesław; Blanchard-Desce, Mireille; Gryko, Daniel (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-01-05)
    A novel non-centrosymmetric π-expanded diketopyrrolopyrrole was designed and synthesized. Strategic placement of tert-butyl groups at the periphery of a diketopyrrolopyrrole allowed us to selectively fuse one moiety via tandem Friedel–Crafts-dehydration reactions, resulting in a non-centrosymmetric dye. The structure of the dye was confirmed by X-ray crystallography, revealing that it contains a ...
  • Theoretical Analysis of NMR Shieldings in XSe and XTe (X= Si, Ge, Sn and Pb): The Spin–Rotation Constant Saga 

    Demissie, Taye Beyene (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-12-21)
    The nuclear spin-rotation (NSR) and absolute nuclear magnetic resonance (NMR) shielding tensors of the nuclei in the series of X<sup>77</sup>Se and X<sup>125</sup>Te (X = <sup>29</sup>Si, <sup>73</sup>Ge, <sup>119</sup>Sn and <sup>207</sup>Pb) are calculated using fourcomponent relativistic density functional theory (DFT) and coupled-cluster singles-doubles with a perturbative triples correction ...
  • Cyclic Voltammetric Study of 2-Hydroxybenzophenone (HBP) Derivatives and the Correspondent Change in the Orbital Energy Levels in Different Solvents 

    Adeniyi, Adebayo A.; Ngake, Tankiso L.; Conradie, Jeanet (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-07-14)
    The experimental UV and CV of five substituted 2-hydroxybenzophenones in solvents acetonitrile, n-dimethylformamide and dimethylsulfoxide are presented. Results obtained were used to determine their experimental highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) and the results were compared to their theoretical model. The derivatives with an electron withdrawing ...
  • Infrared Spectroelectrochemistry of Iron-Nitrosyl Triarylcorroles. Implications for Ligand Noninnocence 

    Rahman, Md. Hafizur; Ryan, Michael D.; Vazquez-Lima, Hugo; Alemayehu, Abraham; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-02-13)
    Recent DFT calculations have suggested that iron nitrosyl triarylcorrole complexes have substantial {FeNO}<sup>7</sup> −corrole<sup>•2−</sup> character. With this formulation, reduction of Fe(C)(NO) complexes, where C = triarylcorrole, should be centered on the corrole macrocycle rather than on the {FeNO}<sup>7</sup> moiety. To verify this proposition, visible and infrared spectroelectrochemical ...
  • 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 ...
  • An averaged polarizable potential for multiscale modeling in phospholipid membranes 

    Witzke, Sarah; List, Nanna Holmgaard; Olsen, Jógvan Magnus Haugaard; Steinmann, Casper; Petersen, Michael; Beerepoot, Maarten; Kongsted, Jacob (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-02-03)
    A set of average atom-centered charges and polarizabilities has been developed for three types of phospholipids for use in polarizable embedding calculations. The lipids investigated are 1,2-dimyristoyl-sn-glycero-3-phosphocholine, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, and 1-palmitoyl-2-oleoyl-sn-glycerol-3-phospho-L-serine given their common use both in experimental and computational ...
  • Electronic circular dichroism of fluorescent proteins: A computational study 

    Pikulska, Anna; Steindal, Arnfinn Hykkerud; Beerepoot, Maarten; Pecul, Magdalena (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-02-03)
    The electronic circular dichroism (ECD) properties of the green fluorescent protein and other fluorescent proteins have been calculated with density functional theory. The influence of different embedding models on the ECD signal of the chromophore has been investigated by modeling the protein environment by the polarizable continuum model (QM/PCM), by the polarizable embedding model (PE-QM/MM), by ...
  • Convergence of environment polarization effects in multiscale modeling of excitation energies 

    Beerepoot, Maarten; Steindal, Arnfinn Hykkerud; Ruud, Kenneth; Olsen, Jógvan Magnus Haugaard; Kongsted, Jacob (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-03-26)
    We present a systematic investigation of the influence of polarization effects from a surrounding medium on the excitation energies of a chromophore. We use a combined molecular dynamics and polarizable embedding time-dependent density functional theory (PE-TD-DFT) approach for chromophores in pro- teins and in homogeneous solvents. The mutual polarization between the chromophore and its ...
  • Ligand and solvent effects on CO2 insertion into group 10 metal alkyl bonds 

    Deziel, Anthony P.; Espinosa, Matthew; Pavlovic, Ljiljana; Charboneau, David J.; Hazari, Nilay; Hopmann, Kathrin Helen; Mercado, Brandon Q. (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-09)
    The insertion of carbon dioxide into metal element σ-bonds is an important elementary step in many catalytic reactions for carbon dioxide valorization. Here, the insertion of carbon dioxide into a family of group 10 alkyl complexes of the type (<sup>R</sup>PBP)M(CH<sub>3</sub>) (<sup>R</sup>PBP = B(NCH<sub>2</sub>PR<sub>2</sub>)<sub>2</sub>C<sub>6</sub>H<sub>4</sub><sup>−</sup>; R = Cy or <sup>t</sup>Bu; ...
  • Rhenium Corrole Dimers: Electrochemical Insights into the Nature of the Metal–Metal Quadruple Bond 

    Alemayehu, Abraham; Mccormick-Mcpherson, Laura J; Conradie, Jeanet; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-17)
    The interaction of free-base triarylcorroles with Re<sub>2</sub>(CO)<sub>10</sub> in 1,2- dichlorobenzene in the presence of 2,6-lutidine at 180 °C under strict anerobic conditions afforded approximately 10% yields of rhenium corrole dimers. The compounds exhibited diamagnetic <sup>1</sup> H NMR spectra consistent with a metal−metal quadruple bond with a σ<sup>2</sup> π<sup>4</sup> δ<sup>2</sup> ...

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