2018
Interplay of Through-Bond Hyperfine and Substituent Effects on the NMR Chemical Shifts in Ru(III) Complexes
JEREMIAS, Lukáš, Jan NOVOTNÝ, Michal REPISKY, Stanislav KOMOROVSKY, Radek MAREK et. al.Základní údaje
Originální název
Interplay of Through-Bond Hyperfine and Substituent Effects on the NMR Chemical Shifts in Ru(III) Complexes
Autoři
JEREMIAS, Lukáš (203 Česká republika, domácí), Jan NOVOTNÝ (203 Česká republika, domácí), Michal REPISKY (703 Slovensko), Stanislav KOMOROVSKY (703 Slovensko) a Radek MAREK (203 Česká republika, garant, domácí)
Vydání
Inorganic Chemistry, American Chemical Society, 2018, 0020-1669
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10402 Inorganic and nuclear chemistry
Stát vydavatele
Spojené státy
Utajení
není předmětem státního či obchodního tajemství
Impakt faktor
Impact factor: 4.850
Kód RIV
RIV/00216224:14740/18:00101065
Organizační jednotka
Středoevropský technologický institut
UT WoS
000441477100012
Klíčová slova anglicky
NMR chemical shift; paramagnetic NMR; hyperfine interaction; Fermi-contact; relativistic DFT; ruthenium
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 13. 3. 2019 13:38, Mgr. Pavla Foltynová, Ph.D.
Anotace
V originále
The links between the molecular structure and nuclear magnetic resonance (NMR) parameters of paramagnetic transition-metal complexes are still relatively unexplored. This applies particularly to the contact term of the hyperfine contribution to the NMR chemical shift. We report combining experimental NMR with relativistic density functional theory (DFT) to study a series of Ru(III) complexes with 2-substituted beta-diketones. A series of complexes with systematically varied substituents was synthesized and analyzed using 1H and 13C NMR spectroscopy. The NMR spectra recorded at several temperatures were used to construct Curie plots and estimate the temperature-independent (orbital) and temperature-dependent (hyperfine) contributions to the NMR shift. Relativistic DFT calculations of electron paramagnetic resonance and NMR parameters were performed to interpret the experimental observations. The effects of individual factors such as basis set, density functional, exact-exchange admixture, and relativity are analyzed and discussed. Based on the calibration study in this work, the fully relativistic Dirac–Kohn–Sham (DKS) method, the GIAO approach (orbital shift), the PBE0 functional with the triple-zeta valence basis sets, and the polarizable continuum model for describing solvent effects were selected to calculate the NMR parameters. The hyperfine contribution to the total paramagnetic NMR (pNMR) chemical shift is shown to be governed by the Fermi-contact (FC) term, and the substituent effect (H vs Br) on the through-bond FC shifts is analyzed, interpreted, and discussed in terms of spin-density distribution, atomic spin populations, and molecular-orbital theory. In contrast to the closed-shell systems of Rh(III), the presence of a single unpaired electron in the open-shell Ru(III) analogs significantly alters the NMR resonances of the ligand atoms distant from the metal center in synergy with the substituent effect.
Návaznosti
| GA15-09381S, projekt VaV |
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| GA18-05421S, projekt VaV |
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| LM2015043, projekt VaV |
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| LM2015085, projekt VaV |
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| LQ1601, projekt VaV |
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