Electronic-Structure Relationship of Spin-Orbit-Induced Heavy Atom on the Light NMR Chemical Shifts Across the Periodic Table

Kód výsledku v IS VaVaI

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Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Electronic-Structure Relationship of Spin-Orbit-Induced Heavy Atom on the Light NMR Chemical Shifts Across the Periodic Table

Popis výsledku v původním jazyce

Analysis of 1H NMR chemical shift trends of the 6th-period hydrides (Cs-At) led to discovery of general electronic-structure principles and mechanisms that dictate the size and sign of the Spin-Orbit-Induced Heavy Atom on the Light Atom (SO-HALA) NMR chemical shifts. Using third order perturbation theory (PT3) analysis we have identified and explained two general mechanisms responsible for SO-HALA shielding and deshielding and their relation to the presence/absence of occupied lone pairs of electron (LP) at HA. In short, when LP are present in HA valence shell, relativistic shielding at the light atom (LA) nuclei is induced by magnetic coupling of LP with HA-LA antibonding molecular orbital, as is the case of 5d2-5d8 and 6p2 and 6p4 HA hydrides. Absence of LP at HA than lead to the dominance of coupling from HA-LA antibonding molecular orbitals, which results in relativistic deshielding found in 4f0, 5d0, 6s0, 6p0 HA hydrides. Introduced principles have a general validity across the periodic table and explain the LA NMR chemical shift trends also for non-hydride ligands. The SO-HALA effect was further linked to the depletion/concentration of the electron density at LA nuclei caused by spin-orbit coupling at HA in the presence of magnetic field. These findings are believed to further increase the already rising interest in linking NMR parameters with the structure/chemical properties of heavy-element compounds.

Název v anglickém jazyce

Electronic-Structure Relationship of Spin-Orbit-Induced Heavy Atom on the Light NMR Chemical Shifts Across the Periodic Table

Popis výsledku anglicky

Analysis of 1H NMR chemical shift trends of the 6th-period hydrides (Cs-At) led to discovery of general electronic-structure principles and mechanisms that dictate the size and sign of the Spin-Orbit-Induced Heavy Atom on the Light Atom (SO-HALA) NMR chemical shifts. Using third order perturbation theory (PT3) analysis we have identified and explained two general mechanisms responsible for SO-HALA shielding and deshielding and their relation to the presence/absence of occupied lone pairs of electron (LP) at HA. In short, when LP are present in HA valence shell, relativistic shielding at the light atom (LA) nuclei is induced by magnetic coupling of LP with HA-LA antibonding molecular orbital, as is the case of 5d2-5d8 and 6p2 and 6p4 HA hydrides. Absence of LP at HA than lead to the dominance of coupling from HA-LA antibonding molecular orbitals, which results in relativistic deshielding found in 4f0, 5d0, 6s0, 6p0 HA hydrides. Introduced principles have a general validity across the periodic table and explain the LA NMR chemical shift trends also for non-hydride ligands. The SO-HALA effect was further linked to the depletion/concentration of the electron density at LA nuclei caused by spin-orbit coupling at HA in the presence of magnetic field. These findings are believed to further increase the already rising interest in linking NMR parameters with the structure/chemical properties of heavy-element compounds.

Druh

O - Ostatní výsledky

CEP obor

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OECD FORD obor

10403 - Physical chemistry

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

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

Rok uplatnění

2018

Kód důvěrnosti údajů

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