title: n→π* Interactions Are Competitive with Hydrogen Bonds.
abstract: Because carbonyl groups can participate in both hydrogen bonds and n→π* interactions, these two interactions likely affect one another. Herein, enhancement of an amidic n→π* interaction is shown to reduce the ability of β-keto amides to tautomerize to the enol, indicating decreased hydrogen-bonding capacity of the amide carbonyl group. Thus, an n→π* interaction can have a significant effect on the strength of a hydrogen bond to the same carbonyl group.
authors.affiliation: Department of Chemistry and ‡Department of Biochemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Newberry
authors.affiliation: Department of Chemistry and ‡Department of Biochemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Orke
authors.affiliation: Department of Chemistry and ‡Department of Biochemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Ronald T
authors.initials: RT
authors.lastname: Raines
mesh_terms: D000577:Amides / Q000737:chemistry*; D006860:Hydrogen Bonding; D007659:Ketones / Q000737:chemistry*; D008968:Molecular Conformation
chemical_list: D000577:Amides; D007659:Ketones