Computational evidence for back donation in an N → O group based on modes of transmission of substituent effects in 3-(4′-substituted) phenylfuroxans
Identifikátory výsledku
Kód výsledku v IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F21%3A00541397" target="_blank" >RIV/61388963:_____/21:00541397 - isvavai.cz</a>
Výsledek na webu
<a href="https://doi.org/10.1007/s12039-021-01885-7" target="_blank" >https://doi.org/10.1007/s12039-021-01885-7</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1007/s12039-021-01885-7" target="_blank" >10.1007/s12039-021-01885-7</a>
Alternativní jazyky
Jazyk výsledku
angličtina
Název v původním jazyce
Computational evidence for back donation in an N → O group based on modes of transmission of substituent effects in 3-(4′-substituted) phenylfuroxans
Popis výsledku v původním jazyce
The N-oxide nitrogen in C-4′ substituted 3-phenyl furoxans occupies a position analogous to C-β in 4-substituted styrenes that have been examined for modes of transmission of substituent effects from the C-4 substituent to C-β. From geometry optimizations through high-level MO theory calculations, it was first ensured that the N-2–C-3 liaison in 3-(4′-substituted)phenyl furoxans retains as much double-bond character as it does in the case of furoxan bearing no substituents and that the para-substituted phenyl and furoxan rings maintain near uniplanarity. The calculations, carried out for such furoxans, chosen to represent a spectrum of effects from electron-donor to electron-acceptor, showed how the change in the 4′-substituent affects electron redistribution within N-oxide group in the way expected: while the residual positive charge at N increases the residual negative charge at O decreases. An increase in the N-oxide bond order (as measured by the Wiberg bond index), together with a small reduction in the N-2–O-6 bond length, was also found. That these effects were not artefacts of the calculation procedure was ensured when the calculations, repeated using a different functional, showed not only inverse dependence of positive N-2 and negative O-6 net charges on N-2–O-6 bond lengths but also confirmatory evidence from N-oxide bond dissociation and second-order perturbation energies. These results are interpreted as demonstrating graded back donation from O to N within the N → O group caused by a combined action of mesomerism and π-polarisation involving the substituent at the para-position of the phenyl group offering a spectrum of effects from electron-releasing to electron-withdrawing. Graphical abstract: Calculations at the B3LYP/6-31++G** level have shown that back donation from O to N in N → O in 3-(4′-X-phenyl) furoxans increase with a change of X from electron-donor to electron-acceptor.
Název v anglickém jazyce
Computational evidence for back donation in an N → O group based on modes of transmission of substituent effects in 3-(4′-substituted) phenylfuroxans
Popis výsledku anglicky
The N-oxide nitrogen in C-4′ substituted 3-phenyl furoxans occupies a position analogous to C-β in 4-substituted styrenes that have been examined for modes of transmission of substituent effects from the C-4 substituent to C-β. From geometry optimizations through high-level MO theory calculations, it was first ensured that the N-2–C-3 liaison in 3-(4′-substituted)phenyl furoxans retains as much double-bond character as it does in the case of furoxan bearing no substituents and that the para-substituted phenyl and furoxan rings maintain near uniplanarity. The calculations, carried out for such furoxans, chosen to represent a spectrum of effects from electron-donor to electron-acceptor, showed how the change in the 4′-substituent affects electron redistribution within N-oxide group in the way expected: while the residual positive charge at N increases the residual negative charge at O decreases. An increase in the N-oxide bond order (as measured by the Wiberg bond index), together with a small reduction in the N-2–O-6 bond length, was also found. That these effects were not artefacts of the calculation procedure was ensured when the calculations, repeated using a different functional, showed not only inverse dependence of positive N-2 and negative O-6 net charges on N-2–O-6 bond lengths but also confirmatory evidence from N-oxide bond dissociation and second-order perturbation energies. These results are interpreted as demonstrating graded back donation from O to N within the N → O group caused by a combined action of mesomerism and π-polarisation involving the substituent at the para-position of the phenyl group offering a spectrum of effects from electron-releasing to electron-withdrawing. Graphical abstract: Calculations at the B3LYP/6-31++G** level have shown that back donation from O to N in N → O in 3-(4′-X-phenyl) furoxans increase with a change of X from electron-donor to electron-acceptor.
Klasifikace
Druh
J<sub>imp</sub> - Článek v periodiku v databázi Web of Science
CEP obor
—
OECD FORD obor
10403 - Physical chemistry
Návaznosti výsledku
Projekt
—
Návaznosti
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Ostatní
Rok uplatnění
2021
Kód důvěrnosti údajů
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Údaje specifické pro druh výsledku
Název periodika
Journal of chemical sciences
ISSN
0974-3626
e-ISSN
0973-7103
Svazek periodika
133
Číslo periodika v rámci svazku
1
Stát vydavatele periodika
IN - Indická republika
Počet stran výsledku
7
Strana od-do
31
Kód UT WoS článku
000629533200002
EID výsledku v databázi Scopus
2-s2.0-85102558278