Beyond Deshielding: NMR Evidence of Shielding in Hydridic and Protonic Hydrogen Bonds

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F25%3A00638120" target="_blank" >RIV/61388963:_____/25:00638120 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/61989100:27740/25:10258747

Výsledek na webu

<a href="https://doi.org/10.1021/acs.jctc.5c00870" target="_blank" >https://doi.org/10.1021/acs.jctc.5c00870</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.jctc.5c00870" target="_blank" >10.1021/acs.jctc.5c00870</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Beyond Deshielding: NMR Evidence of Shielding in Hydridic and Protonic Hydrogen Bonds

Popis výsledku v původním jazyce

The red shift of the X-H stretching frequency, with a significant increase in intensity of the corresponding spectral band and a downfield chemical shift of hydrogen (deshielding) in nuclear magnetic resonance (NMR) spectroscopy, has traditionally been used as a criterion for identifying X-H center dot center dot center dot Y hydrogen bonds (HBs) where X is the hydrogen donor and Y is the acceptor. However, over the past two decades, it has become evident that certain HBs can exhibit a blue shift in the X-H stretching frequency and may also show a decrease in IR intensity, diverging from classical expectations. In this study, we investigate a wide array of HBs, encompassing both red-shifted and blue-shifted systems, as well as protonic and hydridic HB systems. We focus on understanding the underlying electronic conditions behind the reverse chemical shift effects-upfield shifts (shielding) upon HB formation, challenging the view that hydrogen bonding (H-bonding) typically leads to deshielding. We employ state-of-the-art quantum chemical methods, integrating computed NMR shielding tensors and electron deformation density, in combination with experimental NMR, to probe that phenomenon. The computational findings are thoroughly validated against experimental results. Our research confirms that shielding is also possible upon HB formation, thereby broadening the conceptual framework of H-bonding.

Název v anglickém jazyce

Beyond Deshielding: NMR Evidence of Shielding in Hydridic and Protonic Hydrogen Bonds

Popis výsledku anglicky

The red shift of the X-H stretching frequency, with a significant increase in intensity of the corresponding spectral band and a downfield chemical shift of hydrogen (deshielding) in nuclear magnetic resonance (NMR) spectroscopy, has traditionally been used as a criterion for identifying X-H center dot center dot center dot Y hydrogen bonds (HBs) where X is the hydrogen donor and Y is the acceptor. However, over the past two decades, it has become evident that certain HBs can exhibit a blue shift in the X-H stretching frequency and may also show a decrease in IR intensity, diverging from classical expectations. In this study, we investigate a wide array of HBs, encompassing both red-shifted and blue-shifted systems, as well as protonic and hydridic HB systems. We focus on understanding the underlying electronic conditions behind the reverse chemical shift effects-upfield shifts (shielding) upon HB formation, challenging the view that hydrogen bonding (H-bonding) typically leads to deshielding. We employ state-of-the-art quantum chemical methods, integrating computed NMR shielding tensors and electron deformation density, in combination with experimental NMR, to probe that phenomenon. The computational findings are thoroughly validated against experimental results. Our research confirms that shielding is also possible upon HB formation, thereby broadening the conceptual framework of H-bonding.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

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

Název periodika

Journal of Chemical Theory and Computation

ISSN

1549-9618

e-ISSN

1549-9626

Svazek periodika

21

Číslo periodika v rámci svazku

15

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

8

Strana od-do

7495-7502

Kód UT WoS článku

001541348000001

EID výsledku v databázi Scopus

2-s2.0-105013227350