scholarly journals Intramolecular Hydrogen Bonding in α-Keto and α-Alkoxycarboxylic Acids. IV. Electronic Effect in Aryloxyacetic Acids

1961 ◽  
Vol 34 (3) ◽  
pp. 378-381 ◽  
Author(s):  
Michinori \={O}ki ◽  
Minoru Hirota
Keyword(s):  
Hydrogen Bonding ◽  
Electronic Effect ◽  
Intramolecular Hydrogen Bonding ◽  
Intramolecular Hydrogen

Effect of intramolecular hydrogen bonding on the relative acidities of substituted salicylic acids in benzene solution

1967 ◽  
Vol 45 (14) ◽  
pp. 1699-1706 ◽  
Author(s):  
G. E. Dunn ◽  
Thomas L. Penner
Keyword(s):  
Hydrogen Bonding ◽  
Electronic Effect ◽  
Benzene Solution ◽  
Intramolecular Hydrogen Bonding ◽  
Acid Strength ◽  
Carboxyl Group ◽  
Hammett Equation ◽  
Phenolic Group ◽  
Intramolecular Hydrogen ◽  
Salicylic Acids

The relative acidities of fifteen 4- and 5-substituted salicylic acids were determined in benzene solution by potentiometric titration. The potentials at half neutralization (h.n.p.) relative to that of salicylic acid were considered to measure the acidities of the substituted acids relative to the parent acid. These potentials, designated by Δhnp, gave a significantly better correlation with Hammett's sigma constants in an equation of the form proposed by Jaffe, Δhnp = ρ1σ1 + ρ2σ2, than in a simple Hammett equation, Δhnp = ρ1σ1. In these equations the subscripts 1 and 2 refer to the position of a substituent relative to the carboxyl group and to the phenolic group respectively. The value of ρ2/ρ1 was found to be 0.4, indicating that the electronic effect of a substituent on the acid strength via the phenolic hydrogen-bonded path is almost half as large as the direct effect through the carboxyl group. These results, together with the fact that in aqueous solution there is very little if any transmission via the phenolic group, are discussed in terms of intramolecular hydrogen bonding of salicylic acids in benzene and in water.

Theoretical study of intramolecular hydrogen bonding and molecular geometry of 2-trifluoromethylphenol

10.1002/jcc.2 ◽  
1996 ◽  
Vol 17 (16) ◽  
pp. 1804-1819 ◽  
Author(s):  
Attila Kov�cs ◽  
Istv�n Kolossv�ry ◽  
G�bor I. Csonka ◽  
Istv�n Hargittai
Keyword(s):  
Hydrogen Bonding ◽  
Theoretical Study ◽  
Molecular Geometry ◽  
Intramolecular Hydrogen Bonding ◽  
Intramolecular Hydrogen

Intramolecular Hydrogen Bonding Facilitates Electrocatalytic Reduction of Nitrite in Aqueous Solutions

2019 ◽  
Vol 58 (14) ◽  
pp. 9443-9451 ◽  
Author(s):  
Song Xu ◽  
Hyuk-Yong Kwon ◽  
Daniel C. Ashley ◽  
Chun-Hsing Chen ◽  
Elena Jakubikova ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Aqueous Solutions ◽  
Intramolecular Hydrogen Bonding ◽  
Electrocatalytic Reduction ◽  
Intramolecular Hydrogen

Seven-Membered Intramolecular Hydrogen Bonding of Phenols: Database Analysis and Phloroglucinol Model Compounds

2012 ◽  
Vol 2012 (24) ◽  
pp. 4483-4492 ◽  
Author(s):  
Ronald K. Castellano ◽  
Yan Li ◽  
Edwin A. Homan ◽  
Andrew J. Lampkins ◽  
Iris V. Marín ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Intramolecular Hydrogen Bonding ◽  
Model Compounds ◽  
Database Analysis ◽  
Intramolecular Hydrogen

scholarly journals NMR of Natural Products as Potential Drugs

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3763
Author(s):  
Poul Erik Hansen
Keyword(s):  
Natural Products ◽  
Hydrogen Bonding ◽  
Density Functional ◽  
Chemical Shifts ◽  
Isotope Effects ◽  
Density Functional Theory Calculations ◽  
Intramolecular Hydrogen Bonding ◽  
Chemical Equilibria ◽  
Nmr Techniques ◽  
Intramolecular Hydrogen

This review outlines methods to investigate the structure of natural products with emphasis on intramolecular hydrogen bonding, tautomerism and ionic structures using NMR techniques. The focus is on 1H chemical shifts, isotope effects on chemical shifts and diffusion ordered spectroscopy. In addition, density functional theory calculations are performed to support NMR results. The review demonstrates how hydrogen bonding may lead to specific structures and how chemical equilibria, as well as tautomeric equilibria and ionic structures, can be detected. All these features are important for biological activity and a prerequisite for correct docking experiments and future use as drugs.

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