Can a C-H···O interaction be a determinant of conformation?
Whether nonconventional hydrogen bonds, such as the C-H···O interaction, are a consequence or a determinant of conformation is a long-running and unresolved issue. Here we outline a solid-state and quantum mechanical study designed to investigate whether a C-H···O interaction can override the significant trans-planar conformational preferences of α-fluoroamide substituents. A profound change in dihedral angle from trans-planar((OCCF)) to cis-planar((OCCF)) observed on introducing an acceptor group for a C-H···O hydrogen bond is consistent with this interaction functioning as a determinant of conformation in certain systems. This testifies to the potential influence of the C-H···O hydrogen bond and is consistent with the assignment of this interaction as a contributor to overall conformation in both model and natural systems.
Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK.
Christopher R
CR
Jones
Pranjal K
PK
Baruah
Amber L
AL
Thompson
Steve
S
Scheiner
Martin D
MD
Smith
D000577:Amides / Q000737:chemistry*; D005461:Fluorine / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008968:Molecular Conformation; D011789:Quantum Theory
D000577:Amides; D005461:Fluorine