Blar i forfatter Artikler, rapporter og annet (kjemi) "Marek, Radek"

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    • Electron-Spin Structure and Metal-Ligand Bonding in Open-Shell Systems from Relativistic EPR and NMR: A Case Study of Square-Planar Iridium Catalysts 

      Bora, Pankaj L; Novotny, Jan; Ruud, Kenneth; Komorovsky, Stanislav; Marek, Radek (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-28)
      Electron and nuclear magnetic resonance spectroscopies are indispensable and powerful methods for investigating the molecular and electronic structures of open-shell systems. We demonstrate that the NMR and EPR parameters are extremely sensitive quantitative probes for the electronic spin density around heavy-metal atoms and the metal–ligand bonding. Using relativistic density-functional theory, we ...

    • Interpreting the paramagnetic NMR spectra of potential Ru(III) metallodrugs: synergy between experiment and relativistic DFT calculations 

      Novotný, Jan; Sojka, Martin; Komorovsky, Stanislav; Nečas, Marek; Marek, Radek (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-06-16)
      Ruthenium-based compounds are potential candidates for use as anticancer metallodrugs. The central ruthenium atom can be in the oxidation state +2 (e.g., RAPTA, RAED) or +3 (e.g., NAMI, KP). In this study we focus on paramagnetic NAMI analogs of a general structure [4-R-pyH]+ <i>trans</i>-[Ru<sup>III</sup>Cl<sub>4</sub>(DMSO)(4-R-py)]<sup>−</sup>, where 4-R-py stands for a 4-substituted pyridine. ...

    • Linking the Character of the Metal-Ligand Bond to the Ligand NMR Shielding in Transition-Metal Complexes: NMR Contributions from Spin-Orbit Coupling 

      Novotný, Jan; Vícha, Jan; Bora, Pankaj L.; Repisky, Michal; Straka, Michal; Komorovsky, Stanislav; Marek, Radek (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-07-06)
      Relativistic effects significantly affect various spectroscopic properties of compounds containing heavy elements. Particularly in Nuclear Magnetic Resonance (NMR) spectroscopy, the heavy atoms strongly influence the NMR shielding constants of neighboring light atoms. In this account we analyze paramagnetic contributions to NMR shielding constants and their modulation by relativistic spin–orbit ...

    • Structure, solvent, and relativistic effects on the NMR chemical shifts in square-planar transition-metal complexes: Assessment of DFT approaches 

      Vicha, Jan; Novotny, Jan; Straka, Michal; Repisky, Michal; Ruud, Kenneth; Komorovsky, Stanislav; Marek, Radek (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-08-25)
      The role of various factors (structure, solvent, and relativistic treatment) was evaluated for square-planar 4d and 5d transition-metal complexes. The DFT method for calculating the structures was calibrated using a cluster approach and compared to X-ray geometries, with the PBE0 functional (def2-TZVPP basis set) providing the best results, followed closely by the hybrid TPSSH and the MN12SX ...

    • 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 ...