Now showing items 1-20 of 601

    • Nickel Catalyzed Carbonylative Cross Coupling for Direct Access to Isotopically Labeled Alkyl Aryl Ketones 

      Mühlfenzl, Kim; Enemærke, Vitus; Gahlawat, Sahil; Golbækdal, Peter; Munksgaard-Ottosen, Nikoline; Neumann, Karoline; Hopmann, Kathrin Helen; Norrby, Per-Ola; Elmore, Charles; Skrydstrup, Troels (Journal article; Tidsskriftartikkel, 2024-08-15)
      Here we present an effective nickel-catalyzed carbonylative cross-coupling for direct access to alkyl aryl ketones from readily accessible redox-activated tetrachlorophthalimide esters and aryl boronic acids. The methodology, which is run employing only 2.5 equivalents of CO and simple Ni(II) salts as the metal source, exhibits a broad substrate scope under mild conditions. Furthermore, this ...
    • Computational Study of the Ir-Catalyzed Formation of Allyl Carbamates from CO2 

      Gahlawat, Sahil; Artselsmair, Markus; Castro, Abril C; Norrby, Per-Ola; Hopmann, Kathrin Helen (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-08-05)
      We have employed computational methods to investigate the iridium-catalyzed allylic substitution leading to the formation of enantioenriched allyl carbamates from carbon dioxide (CO<sub>2</sub>). The reaction occurs in several steps, with initial formation of an iridium-allyl, followed by nucleophilic attack by the carbamate formed in situ from CO<sub>2</sub> and an amine. A detailed isomeric analysis ...
    • Revisiting the mechanism of asymmetric Ni-catalyzed reductive carbo-carboxylation with CO2: The additives affect the product selectivity 

      Pavlovic, Ljiljana; Carvalho de Oliveira Gomes, Bjørn; Hopmann, Kathrin Helen (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-06-25)
      The mechanistic details of the asymmetric Ni-catalyzed reductive cyclization/carboxylation of alkenes with CO2 have been revisited using DFT methods. Emphasis was put on the enantioselectivity and the mechanistic role of Lewis acid additives and in situ formed salts. Our results show that oxidative addition of the substrate is rate-limiting, with the formed Ni(II)-aryl intermediate preferring a ...
    • Preparation of a high-coordinated-silicon-centered spiro-cyclic compound 

      Kushvaha, Saroj Kumar; Gorantla, Sai Manoj N. V. T.; Kallenbach, Paula; Herbst-Irmer, Regine; Stalke, Dietmar; Roesky, Herbert W. (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-06-10)
      Silicon compounds containing silicon–silicon bond with a variety of unusual oxidation states are quite important, because their high reactivity leads to the formation of a variety of silicon compounds. The isolation of such compounds with unusual oxidation states requires a resilient synthetic strategy. Herein, we report the synthesis of a silicon based spirocyclic compound containing a hyper-valent ...
    • SARS-CoV2 Nsp1 is a metal-dependent DNA and RNA endonuclease 

      Salgueiro, Bruno A.; Saramago, Margarida; Tully, Mark D.; Issoglio, Federico; Silva, Sara T. N.; Paiva, Ana C. F.; Arraiano, Cecília M.; Matias, Pedro M.; Matos, Rute G.; Moe, Elin; Romão, Célia V. (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-03-28)
      Over recent years, we have been living under a pandemic, caused by the rapid spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2). One of the major virulence factors of Coronaviruses is the Non-structural protein 1 (Nsp1), known to suppress the host cells protein translation machinery, allowing the virus to produce its own proteins, propagate and invade new cells. To ...
    • Generating and grading 34 optimised norm-conserving Vanderbilt pseudopotentials for actinides and super-heavy elements in the PseudoDojo 

      Tantardini, Christian; Iliaš, Miroslav; Giantomassi, Matteo; Kvashnin, Alexander G.; Pershina, Valeria; Gonze, Xavier (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-07)
      In the last decades, material discovery has been a very active research field driven by the need to find new materials for many different applications. This has also included materials with heavy elements, beyond the stable isotopes of lead, as most actinides exhibit unique properties that make them useful in various applications. Furthermore, new heavy elements beyond actinides, collectively referred ...
    • Tinned: A symbolic library for response theory and high-order derivatives 

      Gao, Bin (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-05-23)
      A symbolic C++ library—Tinned—has been developed for symbolic differentiation and manipulation in response theory. By recognizing different key building blocks in the density matrix-based (Thorvaldsen et al., J. Chem. Phys. 2008, 129, 214108) and coupled-cluster response theories, we have implemented their corresponding C++ symbolic classes, including but not limited to one- and two-electron ...
    • Combination of separation and degradation methods after PFAS soil washing 

      Uwayezu, Jean Noel; Ren, Zhongfei; Sonnenschein, Sarah; Leiviskä, Tiina; Lejon, Tore; van Hees, Patrick; Karlsson, Patrik; Kumpiene, Jurate; Carabante, Ivan (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-10-26)
      The current study evaluated a three-stage treatment to remediate PFAS-contaminated soil. The treatment consisted of soil washing, foam fractionation (FF), and electrochemical oxidation (EO). The possibility of replacing the third stage, i.e., EO, with an adsorption process was also assessed. The contamination in the studied soils was dominated by perfluorooctane sulfonate (PFOS), with a concentration ...
    • Inverse Hypercorroles 

      Osterloh, W. Ryan; Desbois, Nicolas; Conradie, Jeanet; Gros, Claude P.; Kadish, Karl M.; Ghosh, Abhik (Journal article; Tidsskriftartikkel, 2024-05-02)
      Ground-state and time-dependent density functional theory (TDDFT) calculations with the long-range-corrected, Coulomb-attenuating CAMY-B3LYP exchange-correlation functional and large, all-electron STO-TZ2P basis sets have been used to examine the potential “inverse hypercorrole” character of meso-p-nitrophenyl-appended dicyanidocobalt(III) corrole dianions. The effect is most dramatic for ...
    • Electronic Structure of Metallophlorins: Lessons from Iridium and Gold Phlorin Derivatives 

      Larsen, Simon; Adewuyi, Joseph A.; Kolle Ekaney, Thomas; Conradie, Jeanet; Rousselin, Yoann; Ung, Gaël; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-05-14)
      Phlorins have long remained underexplored relative to their fully conjugated counterparts, such as porphyrins, hydroporphyrins, and corroles. Herein, we have attempted to bridge that knowledge gap with a scalar-relativistic density functional theory (DFT) study of unsubstituted iridium and gold phlorin derivatives and a multitechnique experimental study of iridium-bispyridine and gold complexes of ...
    • Kinetically-Controlled Ni-Catalyzed Direct Carboxylation of Unactivated Secondary Alkyl Bromides without Chain Walking 

      Davies, Jacob; Lyonnet, Julien R.; Carvalho, Bjørn; Sahoo, Basudev; Day, Craig S.; Juliá-Hernández, Francisco; Duan, Yaya; Álvaro Velasco-Rubio, None; Obst, Marc; Norrby, Per-Ola; Hopmann, Kathrin Helen; Martin, Ruben (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-01-09)
      Herein, we report the direct carboxylation of unactivated secondary alkyl bromides enabled by the merger of photoredox and nickel catalysis, a previously inaccessible endeavor in the carboxylation arena. Site-selectivity is dictated by a kinetically controlled insertion of CO<sub>2</sub> at the initial C(sp<sup>3</sup> )−Br site by the rapid formation of Ni(I)−alkyl species, thus avoiding undesired ...
    • Synthesis of Cryptophanes: Recent Advances 

      Kancherla, Sindhu; Hansen, Jørn Hedløy (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-28)
      This review covers the latest developments in the synthesis of cryptophane host molecules since the publication of the last extensive review by Brotin and Dutasta in 2009. The literature has been categorized according to the synthetic method for generating the cryptophane core and we also emphasize emerging late-stage functionalization approaches. The synthetic strategies towards cryptophanes ...
    • VAMPyR—A high-level Python library for mathematical operations in a multiwavelet representation 

      Bjørgve, Magnar; Tantardini, Christian; Jensen, Stig Rune; Gerez Sazo, Gabriel Adolfo; Wind, Peter Ariaan; Eikås, Roberto Di Remigio; Dinvay, Evgueni; Frediani, Luca (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-04-26)
      Wavelets and multiwavelets have lately been adopted in quantum chemistry to overcome challenges presented by the two main families of basis sets: Gaussian atomic orbitals and plane waves. In addition to their numerical advantages (high precision, locality, fast algorithms for operator application, linear scaling with respect to system size, to mention a few), they provide a framework that narrows ...
    • Asymmetric Boracarboxylation of Styrenes Using Carbon Dioxide 

      Pettersen, Martin; Do, Cuong Dat; Gorantla, Sai Manoj N. V. T.; Obst, Marc; Damm, Roman; Putra, Anggi Eka; Gevorgyan, Ashot; Pavlovic, Ljiljana; Hopmann, Kathrin Helen; Bayer, Annette (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-04-22)
      The boracarboxylation reaction has potential for the production of natural products and drug candidates, but the development of an asymmetric version of this transformation is challenging. We report an enantioselective boracarboxylation of styrenes, enabled by a copper catalyst containing chiral phosphines. Our experimental conditions provide yields between 31–76% and enantiomeric ratios from ...
    • Hypsochlorins 

      Larsen, Simon; Conradie, Jeanet; Desbois, Nicolas; Gros, Claude Philippe; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-03-19)
      Both the Soret and Q bands of chlorin e6 complexes blueshift on going from Zn to Pd to Pt as the coordinated metal, establishing the latter two complexes as hypsochlorins. DFT/TDDFT calculations indicate that the blueshifts appear to be related to the presence of the electronegative metal ion, which lowers the orbital energies of the HOMO and HOMO-1, while leaving the LUMOs relatively unaffected.
    • Theoretical Photoelectron Spectroscopy of Metal-Metal Quintuple Bonds: Relativity-Driven Reordering of Frontier Orbitals 

      Ghosh, Abhik; Conradie, Jeanet (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-03-01)
      A recent reinvestigation of the gas-phase photoelectron spectra of Group 6 metal−metal quadruple-bonded complexes with scalar-relativistic DFT calculations showed that common exchange-correlation functionals reproduce the lowest ionization potentials in a semiquantitative manner. The finding encouraged us to undertake a DFT study of metal− metal quintuple bonds in a set of bisamidinato complexes ...
    • Exploring the Frozen Armory: Antiphage Defense Systems in Cold-Adapted Bacteria with a Focus on CRISPR-Cas Systems 

      Sandsdalen, Greta Daae; Kumar, Animesh; Hjerde, Erik (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-05-20)
      Our understanding of the antiphage defense system arsenal in bacteria is rapidly expanding, but little is known about its occurrence in cold-adapted bacteria. In this study, we aim to shed light on the prevalence and distribution of antiphage defense systems in cold-adapted bacteria, with a focus on CRISPR-Cas systems. Using bioinformatics tools, Prokaryotic Antiviral Defense LOCator (PADLOC) and ...
    • Theoretical Photoelectron Spectroscopy of Quadruple-Bonded Dimolybdenum(II,II) and Ditungsten(II,II) Paddlewheel Complexes: Performance of Common Density Functional Theory Methods 

      Ghosh, Abhik; Conradie, Jeanet (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-03-03)
      We have revisited the gas-phase photoelectron spectra of quadruplebonded dimolybdenum(II,II) and ditungsten(II,II) paddlewheel complexes with modern density functional theory methods and obtained valuable calibration of four well-known exchange−correlation functionals, namely, BP86, OLYP, B3LYP*, and B3LYP. All four functionals were found to perform comparably, with discrepancies between calculated ...
    • Inverse Photoemission Spectroscopy of Coinage Metal Corroles: Comparison with Solution-Phase Electrochemistry 

      Giovanelli, Luca; Ksari, Younal; Mrezguia, Hela; Salomon, Eric; Minissale, Marco; Alemayehu, Abraham; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-06-19)
      A combined direct and inverse photoemission study of coinage metal corroles suggests that the latter technique, in favorable cases, can provide some additional information relative to electrochemical measurements. Thus, whereas inverse photoemission spectroscopy (IPES) provides relative electron affinities for electron addition to different unoccupied orbitals, electrochemical reduction potentials ...
    • Rethinking gold(II) porphyrins: an inherent wave distortion 

      Ghosh, Abhik; Conradie, Jeanet (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-01-23)
      Relativistic DFT (OLYP-D3/ZORA-STO-TZ2P) calculations predict low adiabatic ionization potentials for gold(II) porphyrins, from 4.60 eV for Au[TPP] (TPP = tetraphenylporphyrin) to 5.34 eV for Au[TPFPP] [TPFPP = tetrakis(pentafluorophenyl)porphyrin]. These values are over 1 eV lower than those calculated for analogous silver(II) porphyrins, reflecting much greater relativistic destabilization of ...