Direct observation of intramolecular hydrogen bonding of a hydroxy proton to an indenide carbanion in apolar and polar non-hydrogen bond donor solvents by NMR and IR spectroscopy

1992 ◽  
Vol 114 (27) ◽  
pp. 10869-10873 ◽  
Author(s):  
Ian McEwen ◽  
Per Ahlberg
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Ir Spectroscopy ◽  
Direct Observation ◽  
Intramolecular Hydrogen Bonding ◽  
Hydrogen Bond Donor ◽  
Hydroxy Proton ◽  
Intramolecular Hydrogen

scholarly journals Conformational analysis and intramolecular interactions in monosubstituted phenylboranes and phenylboronic acids

2013 ◽  
Vol 9 ◽  
pp. 1127-1134 ◽  
Author(s):  
Josué M Silla ◽  
Rodrigo A Cormanich ◽  
Roberto Rittner ◽  
Matheus P Freitas
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Conformational Analysis ◽  
Conformational Equilibrium ◽  
Intramolecular Hydrogen Bonding ◽  
Intramolecular Interactions ◽  
Coupling Constant ◽  
Intramolecular Hydrogen ◽  
Phenylboronic Acids ◽  
Electron Donation

A 1 TS J F,H(O) coupling pathway, dictated by a hydrogen bond, in some 2-fluorobenzoic acids has been observed, while such an interaction does not occur in 2-fluorophenol. Thus, this work reports the conformational analysis of 2-fluorophenylboronic acid (1), in order to evaluate a possible intramolecular OH∙∙∙F hydrogen bond in comparison to an nF→pB interaction, which mimics the quantum nF→σ*OH hydrogen bond that would be expected in 2-fluorophenol. 2-Fluorophenylborane (3), which does not experience hydrogen bonding, was used to verify whether nF→pB interaction governs the conformational equilibrium in 1 due to a predominant OH∙∙∙F hydrogen bond or to other effects. A series of 2-X-phenylboranes (X = Cl, Br, NH2, PH2, OH and SH) were further computationally analyzed to search for electron donors to boron, capable of influencing the conformational equilibrium. Overall, the intramolecular OH∙∙∙F hydrogen bond in 1 is quite stabilizing and dictates the 1 h J F,H(O) coupling constant. Moreover, electron donation to the empty p orbital of boron (for noncoplanar BH2 moiety relative to the phenyl ring) is also significantly stabilizing for the NH2 and PH2 derivatives, but not enough to make the corresponding conformers appreciably populated, because of steric effects and the loss of πCC→pB resonance. Thus, the results found earlier for 2-fluorophenol about the lack of intramolecular hydrogen bonding are now corroborated.

Theoretical aspects of the enhancement of metal binding affinity by intramolecular hydrogen bonding and modulating pKavalues

2017 ◽  
Vol 41 (24) ◽  
pp. 15110-15119 ◽  
Author(s):  
Ahmad Motahari ◽  
Alireza Fattahi
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Binding Affinity ◽  
Metal Binding ◽  
Intramolecular Hydrogen Bonding ◽  
Hydrogen Bond Network ◽  
Bond Network ◽  
The Stability ◽  
Intramolecular Hydrogen

The stability balance shows that the hydrogen bond network and modulation of pKavalues can enhance the metal binding affinity.

scholarly journals Separation of planar rotamers through intramolecular hydrogen bonding in polysubstituted 5-nitrosopyrimidines

2014 ◽  
Vol 50 (94) ◽  
pp. 14892-14895 ◽  
Author(s):  
L. Čechová ◽  
E. Procházková ◽  
I. Císařová ◽  
M. Dračínský ◽  
Z. Janeba
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Intramolecular Hydrogen Bond ◽  
Chemical Species ◽  
Intramolecular Hydrogen Bonding ◽  
Nitroso Group ◽  
Group Orientation ◽  
Intramolecular Hydrogen

Unique isolation of pairs of planar rotamers, planamers, as chemical species differing only in nitroso group orientation, separable through the presence of a single intramolecular hydrogen bond, is reported.

THE STUDY OF HYDROGEN BONDING AND RELATED PHENOMENA BY SPECTROSCOPIC METHODS: PART VII. INTRAMOLECULAR HYDROGEN BONDING AND STERIC INTERACTIONS IN o-NITROBENZALDEHYDE AND RELATED COMPOUNDS

1962 ◽  
Vol 40 (10) ◽  
pp. 1891-1898 ◽  
Author(s):  
W. F. Forbes
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Infrared Spectra ◽  
Intramolecular Hydrogen Bonding ◽  
Spectroscopic Methods ◽  
Steric Interactions ◽  
Spectral Changes ◽  
Suitable Reference ◽  
Intramolecular Hydrogen ◽  
Related Compounds

Certain unusual features in the infrared spectra of o-nitrobenzaldehyde have been interpreted either in terms of an intramolecular hydrogen bond or in terms of steric interactions. As an extension of these studies we have investigated the ultraviolet, infrared, and n.m.r. spectra of o-nitrobenzaldehyde and of suitable reference compounds and have re-examined the available other evidence. It is concluded that the observed spectral changes can best be explained in terms of steric interactions rather than in terms of intramolecular hydrogen bonding.

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