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H-bond cooperativity: polarisation effects on secondary amides

Formation of a H-bond with an amide carbonyl oxygen atom increases the strength of subsequent H-bonds formed by the amide NH, due to polarisation of the bond. The magnitude of this effect has been quantified by measuring association constants for the formation of 1 : 1 complexes of 2-hydroxylbenzami...

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Autores principales: Soloviev, Daniil O., Hanna, Fergal E., Misuraca, Maria Cristina, Hunter, Christopher A.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Royal Society of Chemistry 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9580511/
https://www.ncbi.nlm.nih.gov/pubmed/36320903
http://dx.doi.org/10.1039/d2sc04271a
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author Soloviev, Daniil O.
Hanna, Fergal E.
Misuraca, Maria Cristina
Hunter, Christopher A.
author_facet Soloviev, Daniil O.
Hanna, Fergal E.
Misuraca, Maria Cristina
Hunter, Christopher A.
author_sort Soloviev, Daniil O.
collection PubMed
description Formation of a H-bond with an amide carbonyl oxygen atom increases the strength of subsequent H-bonds formed by the amide NH, due to polarisation of the bond. The magnitude of this effect has been quantified by measuring association constants for the formation of 1 : 1 complexes of 2-hydroxylbenzamides with tri-n-butyl phosphine oxide. In 2-hydroxybenzamides, there is an intramolecular H-bond between the phenol OH group and the carbonyl oxygen atom. Comparison of the association constants measured for compounds with and without the 2-hydroxy group allows direct quantification of the effect of the intramolecular H-bond on the H-bond donor properties of the amide NH group. Substituents were used to modulate the strength of the intramolecular and intermolecular H-bonds. The presence of an intramolecular H-bond increases the strength of the intermolecular H-bond by more than one order of magnitude in n-octane solution. The increase in the H-bond donor parameter used to describe the amide NH group is directly proportional to the H-bond donor parameter of the phenol OH group that makes the intramolecular H-bond. These polarisation effects will lead to substantial cooperativity in complex systems that feature networks of non-covalent interactions, and the measurements described here provide a quantitative basis for understanding such phenomena.
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spelling pubmed-95805112022-10-31 H-bond cooperativity: polarisation effects on secondary amides Soloviev, Daniil O. Hanna, Fergal E. Misuraca, Maria Cristina Hunter, Christopher A. Chem Sci Chemistry Formation of a H-bond with an amide carbonyl oxygen atom increases the strength of subsequent H-bonds formed by the amide NH, due to polarisation of the bond. The magnitude of this effect has been quantified by measuring association constants for the formation of 1 : 1 complexes of 2-hydroxylbenzamides with tri-n-butyl phosphine oxide. In 2-hydroxybenzamides, there is an intramolecular H-bond between the phenol OH group and the carbonyl oxygen atom. Comparison of the association constants measured for compounds with and without the 2-hydroxy group allows direct quantification of the effect of the intramolecular H-bond on the H-bond donor properties of the amide NH group. Substituents were used to modulate the strength of the intramolecular and intermolecular H-bonds. The presence of an intramolecular H-bond increases the strength of the intermolecular H-bond by more than one order of magnitude in n-octane solution. The increase in the H-bond donor parameter used to describe the amide NH group is directly proportional to the H-bond donor parameter of the phenol OH group that makes the intramolecular H-bond. These polarisation effects will lead to substantial cooperativity in complex systems that feature networks of non-covalent interactions, and the measurements described here provide a quantitative basis for understanding such phenomena. The Royal Society of Chemistry 2022-10-03 /pmc/articles/PMC9580511/ /pubmed/36320903 http://dx.doi.org/10.1039/d2sc04271a Text en This journal is © The Royal Society of Chemistry https://creativecommons.org/licenses/by/3.0/
spellingShingle Chemistry
Soloviev, Daniil O.
Hanna, Fergal E.
Misuraca, Maria Cristina
Hunter, Christopher A.
H-bond cooperativity: polarisation effects on secondary amides
title H-bond cooperativity: polarisation effects on secondary amides
title_full H-bond cooperativity: polarisation effects on secondary amides
title_fullStr H-bond cooperativity: polarisation effects on secondary amides
title_full_unstemmed H-bond cooperativity: polarisation effects on secondary amides
title_short H-bond cooperativity: polarisation effects on secondary amides
title_sort h-bond cooperativity: polarisation effects on secondary amides
topic Chemistry
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9580511/
https://www.ncbi.nlm.nih.gov/pubmed/36320903
http://dx.doi.org/10.1039/d2sc04271a
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