Mechanisms of Ligand Hyperfine Coupling in Transition-Metal Complexes: σ and π Transmission Pathways

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F24%3A00135949" target="_blank" >RIV/00216224:14310/24:00135949 - isvavai.cz</a>

Výsledek na webu

<a href="https://pubs.acs.org/doi/10.1021/acs.inorgchem.3c04425" target="_blank" >https://pubs.acs.org/doi/10.1021/acs.inorgchem.3c04425</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.inorgchem.3c04425" target="_blank" >10.1021/acs.inorgchem.3c04425</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Mechanisms of Ligand Hyperfine Coupling in Transition-Metal Complexes: σ and π Transmission Pathways

Popis výsledku v původním jazyce

Theoretical interpretation of hyperfine interactions was pioneered in the 1950s-1960s by the seminal works of McConnell, Karplus, and others for organic radicals and by Watson and Freeman for transition-metal (TM) complexes. In this work, we investigate a series of octahedral Ru(III) complexes with aromatic ligands to understand the mechanism of transmission of the spin density from the d-orbital of the metal to the s-orbitals of the ligand atoms. Spin densities and spin populations underlying ligand hyperfine couplings are analyzed in terms of pi-conjugative or sigma-hyperconjugative delocalization vs. spin polarization based on symmetry considerations and restricted open-shell vs. unrestricted wave function analysis. The transmission of spin density is shown to be most efficient in the case of symmetry-allowed pi-conjugative delocalization, but when the pi-conjugation is partially or fully symmetry-forbidden, it can be surpassed by the sigma-hyperconjugative delocalization. Despite a lower spin population of the ligand in sigma-hyperconjugative transmission, the hyperfine couplings can be larger because of the direct involvement of the ligand s-orbitals in this delocalization pathway. We demonstrate a quantitative correlation between the hyperfine couplings of aromatic ligand atoms and the characteristics of the metal-ligand bond modulated by the trans substituent, a hyperfine trans effect.

Název v anglickém jazyce

Mechanisms of Ligand Hyperfine Coupling in Transition-Metal Complexes: σ and π Transmission Pathways

Popis výsledku anglicky

Theoretical interpretation of hyperfine interactions was pioneered in the 1950s-1960s by the seminal works of McConnell, Karplus, and others for organic radicals and by Watson and Freeman for transition-metal (TM) complexes. In this work, we investigate a series of octahedral Ru(III) complexes with aromatic ligands to understand the mechanism of transmission of the spin density from the d-orbital of the metal to the s-orbitals of the ligand atoms. Spin densities and spin populations underlying ligand hyperfine couplings are analyzed in terms of pi-conjugative or sigma-hyperconjugative delocalization vs. spin polarization based on symmetry considerations and restricted open-shell vs. unrestricted wave function analysis. The transmission of spin density is shown to be most efficient in the case of symmetry-allowed pi-conjugative delocalization, but when the pi-conjugation is partially or fully symmetry-forbidden, it can be surpassed by the sigma-hyperconjugative delocalization. Despite a lower spin population of the ligand in sigma-hyperconjugative transmission, the hyperfine couplings can be larger because of the direct involvement of the ligand s-orbitals in this delocalization pathway. We demonstrate a quantitative correlation between the hyperfine couplings of aromatic ligand atoms and the characteristics of the metal-ligand bond modulated by the trans substituent, a hyperfine trans effect.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10400 - Chemical sciences

Projekt

<a href="/cs/project/GA21-06991S" target="_blank" >GA21-06991S: Relativistické efekty v paramagnetické NMR spektroskopii</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Inorganic Chemistry

ISSN

0020-1669

e-ISSN

1520-510X

Svazek periodika

63

Číslo periodika v rámci svazku

19

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

13

Strana od-do

8580-8592

Kód UT WoS článku

001227850700001

EID výsledku v databázi Scopus

2-s2.0-85193102505