Hydrogen bonding, between carbonyl groups

Figure 7-25. Hydrogen bonding between carbonyl groups and amino N-H groups is a useful structural feature for the assembly of supramolecules. Part of the hydrogen bonding network present in the solid state lattice of the zwitterionic compound anthranilic acid is shown in a). The self-complementary hydrogen bonding possible with an amide is shown in b).

PolyCmethacrylic acid) was used as template for polymerization of N-vinylpyrrolidone. Interaction between poly(methacrylic acid) and N-vinylpyrrolidone is based on the hydrogen bonding between COOH groups and carbonyl groups in the monomer ... 

With carboxylic acids, the simple dimeric species are reasonably persistent in solution (and the gas phase), but the more extended structures are generally limited to the solid state. Hydrogen bonding between carbonyl oxygen atoms and amino N-H groups has... 

It appears probable that the effectiveness of the chiral cobalt systems studied thus far is a function, in part at least, of secondary bonding between the quinine ligand and the substrate, possibly via hydrogen bonding between carbonyl and hydroxyl groups. 

Figure 2.17. Hydrogen bonding in antiparallel (3 sheet. Antiparallel hydrogen bonding between carbonyl and amide groups within the peptide unit stabilizes the (3 extended conformation.

Studies have shown that increases in asphalt viscosity with oxidation can be correlated with increases in carbonyl formation (20). Almost certainly this hardening results from hydrogen bonding between heteroatom groups in asphaltene molecules and also between polar aromatics, which then may become asphaltenes (66-69). This association strongly impacts attempts to measure molecular size by SEC or colligative properties. 

Open-chain p-keto esters with an a-amido or a-(alkoxycarbonyl)amino substituents can be hydrogenated with excellent syn-diastereoselectivity [3,41] probably due to conformational lock by a potential hydrogen bond between NH group and the carbonyl oxygen atom of the ester [3]. 

Intramolecular hydrogen bond between the —OH group and the carbonyl oxygen... 

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