Stretching force constants as descriptors of energy and geometry of F···HF hydrogen bonds

Elena Yu Tupikina; Konstantin G Tokhadze; Valerii V Karpov; Gleb S Denisov; Peter M Tolstoy

doi:10.1016/j.saa.2020.118677

Stretching force constants as descriptors of energy and geometry of F···HF hydrogen bonds

Spectrochim Acta A Mol Biomol Spectrosc. 2020 Nov 5:241:118677. doi: 10.1016/j.saa.2020.118677. Epub 2020 Jul 3.

Authors

Elena Yu Tupikina¹, Konstantin G Tokhadze², Valerii V Karpov³, Gleb S Denisov², Peter M Tolstoy⁴

Affiliations

¹ Institute of Chemistry, St. Petersburg State University, 26 Universitetskii pr., Petergof, St. Petersburg 198504, Russia. Electronic address: elenatupikina@gmail.com.
² Department of Physics, St. Petersburg State University, 3 Uljanoyskaya str., Petergof, St. Petersburg 198504, Russia.
³ Institute of Chemistry, St. Petersburg State University, 26 Universitetskii pr., Petergof, St. Petersburg 198504, Russia.
⁴ Institute of Chemistry, St. Petersburg State University, 26 Universitetskii pr., Petergof, St. Petersburg 198504, Russia. Electronic address: peter.tolstoy@spbu.ru.

PMID: 32652286
DOI: 10.1016/j.saa.2020.118677

Abstract

In this work applicability of proton donor group stretching vibration force constants k_s and intermolecular stretching force constants k_σ for evaluations of hydrogen bond strength and geometry are discussed. For a set of 30 complexes with F···HF hydrogen bonds in a wide range 0.5-48 kcal/mol by means of quantum chemical calculations equilibrium geometries, complexation energies, vibrational frequencies and corresponding force constants were calculated (MP2/aug-cc-pVTZ). It is shown, that properties of a hydrogen bond are more strictly correlated with the values of force constants than with vibrational frequencies. Easy-to-use equations for estimations of hydrogen bond energy ∆E and geometry (r_FH, r_FF) based on k_s and k_σ values are proposed.

Keywords: Force constants; Hydrogen bonds; IR spectroscopy; Quantum chemistry; Vibrational frequency.