Amide hydrogen bonding in organic medium

Dependence of amide vibrations on hydrogen bonding.

The effect of hydrogen bonding on the amide group vibrational spectra has traditionally been rationalized by invoking a resonance model where hydrogen bonding impacts the amide functional group by stabilizing its [(-)O-C=NH (+)] structure over the [O=C-NH] structure. However, Triggs and Valentini's UV-Raman study of solvation and hydrogen bonding effects on epsilon-caprolactum, N, N-dimethylace...

Knowledge-based model of hydrogen-bonding propensity in organic crystals.

A new method is presented to predict which donors and acceptors form hydrogen bonds in a crystal structure, based on the statistical analysis of hydrogen bonds in the Cambridge Structural Database (CSD). The method is named the logit hydrogen-bonding propensity (LHP) model. The approach has a potential application in identifying both likely and unusual hydrogen bonding, which can help to ration...

Strong Hydrogen Bonding to the Amide Nitrogen Atom in an "Amide Proton Sponge": Consequences for Structure and Reactivity

The carbonyl oxygen atom of the amide functional group is universally believed to be the thermodynamically preferred site of protonation in amides;[1] however, N protonation has been proposed to play a key role in biologically important reactions of peptides and proteins such as acid-catalyzed peptide hydrolysis[2] and cis ± trans isomerization about the CÿN bond.[3] Extensive research into the...

Probing backbone hydrogen bonding in PDZ/ligand interactions by protein amide-to-ester mutations.

PDZ domains are scaffolding modules in protein-protein interactions that mediate numerous physiological functions by interacting canonically with the C-terminus or non-canonically with an internal motif of protein ligands. A conserved carboxylate-binding site in the PDZ domain facilitates binding via backbone hydrogen bonds; however, little is known about the role of these hydrogen bonds due to...

Hydrogen Bonding in Aromatic Amide Derivatives - The X-Ray Crystallographic Investigation