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Intimate interactions with carbonyl groups: dipole-dipole or n??*?

ABSTRACT: Amide carbonyl groups in proteins can engage in C?O···C?O and C-X···C?O interactions, where X is a halogen. The putative involvement of four poles suggests that these interactions are primarily dipolar. Our survey of crystal structures with a C-X···C?O contact that is short (i.e., within the sum of the X and C van der Waals radii) revealed no preferred C-X···C?O dihedral angle. Moreover, we found that structures with a short X(-)···C?O contact display the signatures of an n??* interaction. We conclude that intimate interactions with carbonyl groups do not require a dipole.

SUBMITTER: Kamer KJ

PROVIDER: S-EPMC3586291 | biostudies-literature | 2013 Mar

REPOSITORIES: biostudies-literature

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Intimate interactions with carbonyl groups: dipole-dipole or n→π*?

Kamer Kimberli J KJ Choudhary Amit A Raines Ronald T RT

The Journal of organic chemistry 20121210 5

Amide carbonyl groups in proteins can engage in C═O···C═O and C-X···C═O interactions, where X is a halogen. The putative involvement of four poles suggests that these interactions are primarily dipolar. Our survey of crystal structures with a C-X···C═O contact that is short (i.e., within the sum of the X and C van der Waals radii) revealed no preferred C-X···C═O dihedral angle. Moreover, we found that structures with a short X(-)···C═O contact display the signatures of an n→π* interaction. We co ...[more]

PMID: 23163960

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