Relativistic SO-HALA Effects in Light-Atom NMR: Understanding and Applications
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28610%2F26%3A63601798" target="_blank" >RIV/70883521:28610/26:63601798 - isvavai.cz</a>
Result on the web
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DOI - Digital Object Identifier
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Alternative languages
Result language
angličtina
Original language name
Relativistic SO-HALA Effects in Light-Atom NMR: Understanding and Applications
Original language description
Nuclear magnetic resonance (NMR) chemical shifts of light atoms adjacent to heavy elements frequentlydisplay anomalous trends and exceptional deviations that cannot be rationalized within nonrelativisticframeworks. This contribution summarizes advances in understanding and exploiting spin–orbit heavyatom-on-light-atom (SO-HALA) effects through combined relativistic quantum-chemical methods andorbital-level analysis.A predictive analysis framework based on third-order perturbation theory (PT3) has been developed toconnect measurable light-atom shifts to the electronic structure of the heavy center. This framework revealsfundamental orbital magnetic coupling pathways controlling both the magnitude and sign of SO-HALAcontributions. A practical principle—the "lone-pair rule"—has been established: heavy atoms with occupiednonbonding lone pairs induce shielding at adjacent light nuclei, whereas heavy atoms with formally emptyvalence shells produce deshielding effects. This rule has been validated systematically across the PeriodicTable, notably rationalizing characteristic trends in sixth-period hydrides where SO-HALA contributionscan dominate observed experimental shifts.SO-HALA effects can substantially expand accessible chemical-shift windows. In subvalent thallium(I) andlead(II) compounds, exceptionally large SO contributions to directly bound light atoms have been found,suggesting experimentally "missing" resonances that lie far outside conventional ranges. Structure–propertyrelationships modulating SO-HALA efficiency—including oxidation state, coordination environment, andbond covalency—have been quantified through real-space descriptors.Relativistic effects may also propagate beyond classical covalent pathways: "through-space" transmissionof SO-HALA contributions via hydrogen bonds has been demonstrated through combined solid-state NMRand computational studies. These results position relativistic NMR as an increasingly predictive andactionable tool for heavy-element chemistry, bonding analysis, and structural determination.
Czech name
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Czech description
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Classification
Type
O - Miscellaneous
CEP classification
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OECD FORD branch
10301 - Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect)
Result continuities
Project
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Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2026
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů