title: A molecular balance for measuring aliphatic CH-π interactions.
abstract: A series of conformationally flexible bicyclic N-arylimides were employed as molecular balances to study the weak aliphatic CH-π interaction between alkyl and arene groups. The formation of intramolecular CH-π interactions in the folded conformers was characterized by X-ray crystallography. The strengths of the interactions were characterized in CDCl(3) by the changes in the folded/unfolded ratios, as measured by (1)H NMR. The CH-π interaction between a methyl group and an aromatic surface was ∼1.0 kcal/mol and was easily disrupted or masked by conformational entropy and repulsive steric interactions.
authors.affiliation: Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, USA.
authors.forename: William R
authors.initials: WR
authors.lastname: Carroll
authors.forename: Chen
authors.initials: C
authors.lastname: Zhao
authors.forename: Mark D
authors.initials: MD
authors.lastname: Smith
authors.forename: Perry J
authors.initials: PJ
authors.lastname: Pellechia
authors.forename: Ken D
authors.initials: KD
authors.lastname: Shimizu
mesh_terms: D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000737:chemistry; D002244:Carbon / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006859:Hydrogen / Q000737:chemistry*; D007094:Imides / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D013816:Thermodynamics
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D007094:Imides; D002244:Carbon; D006859:Hydrogen