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Updated: Jul 5, 2026

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
Published on: September 17, 2017
Blue shifts vs red shifts in sigma-hole bonding
Jane S Murray1, Monica C Concha, Pat Lane
1Department of Chemistry, University of New Orleans, New Orleans, LA 70148, USA. jsmurray@uno.edu
Abstract:
Sigma-hole bonding is a noncovalent interaction between a region of positive electrostatic potential on the outer surface of a Group V, VI, or VII covalently-bonded atom (a sigma-hole) and a region of negative potential on another molecule, e.g., a lone pair of a Lewis base. We have investigated computationally the occurrence of increased vibration frequencies (blue shifts) and bond shortening vs decreased frequencies (red shifts) and bond lengthening for the covalent bonds to the atoms having the sigma-holes (the sigma-hole donors). Both are possible, depending upon the properties of the donor and the acceptor. Our results are consistent with models that were developed earlier by Hermansson and by Qian and Krimm in relation to blue vs red shifting in hydrogen bond formation. These models invoke the derivatives of the permanent and the induced dipole moments of the donor molecule.
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