Determination of the orbital and paramagnetic contributions to the 1H and 13C NMR chemical shifts of ruthenium(III) complexes
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Year of publication | 2017 |
Type | Appeared in Conference without Proceedings |
MU Faculty or unit | |
Citation | JEREMIAS, Lukáš, Jan NOVOTNÝ, Michal REPISKY, Stanislav KOMOROVSKY and Radek MAREK. Determination of the orbital and paramagnetic contributions to the 1H and 13C NMR chemical shifts of ruthenium(III) complexes. In 32nd NMR Valtice - Central European NMR Meeting. 2017. |
Description | The paramagnetic NMR (pNMR) spectroscopy is becoming crucially important in many areas of research despite the fact that unpaired electrons affect the NMR chemical-shift tensors, the isotropic NMR chemical shifts, and indirect nuclear spin-spin coupling constants [1]. Therefore the resonance frequencies for paramagnetic species lie typically out of the standard chemical-shift ranges for their diamagnetic analogs and the NMR signals are significantly broadened. The observed total NMR chemical shift can be decomposed into temperature-independent orbital term and temperature-dependent paramagnetic term [2]. In this study, the orbital and paramagnetic contributions to the NMR chemical shifts were determined experimentally from the 1H and 13C NMR measurements at various temperatures for a series of ruthenium(III) complexes - Ru(X-acac)3 and Ru(dbm)3 (X = H, Br, Me, NO2; acac = acetylacetonate; dbmH = dibenzoylmethane). The relativistic DFT calculations (two-component SO-ZORA and four-component DKS) were performed to assist with the resonance assignments. [1] J. Autschbach, In D. A. Dixon, Annual Reports in Computational Chemistry, Elsevier, 2015, 11, 3–36. [2] J. Novotný, M. Sojka, S. Komorovsky, M. Nečas, R. Marek, J. Am. Chem. Soc., 2016, 138, 8432–8445. |
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