DOI

In this work we evaluate the possibility of using the NMR and IR spectral properties of the P =O group to estimate the geometry and strength of hydrogen bonds which it forms with OH-, NH-And CH-Acids. The results of the DFT study of 70 hydrogen-bonded 1: 1 complexes of a model trimethylphosphine oxide, Me3PO, with various proton donors in the gas phase and in aprotic medium (modelled as a polarizable continuum) are presented. Four types of hydrogen bonds with the general formula Me3POâH-A were considered, where the A atom is O, C, and N (neutral or cationic acids). Within the selected set of complexes the hydrogen bond energy varies over a wide range (ca. 0-85 kJ mol-1). We show that it is possible to use simple correlations to estimate the energy and geometry of OHO, NHO and CHO hydrogen bonds from the changes of isotropic 31P NMR chemical shifts and harmonic PO stretching vibration frequencies upon complexation. Such correlations also could be used to estimate the proton-donating ability (and Brønsted acidity; pKa) of OH acids.

Original languageEnglish
Pages (from-to)7121-7133
Number of pages13
JournalPhysical Chemistry Chemical Physics
Volume24
Issue number11
Early online date25 Feb 2022
DOIs
StatePublished - 25 Feb 2022

    Research areas

  • CYCLOTRON RESONANCE DETERMINATION, ELECTRON-DENSITY PROPERTIES, CHEMICAL-SHIFTS, PROTON-TRANSFER, GAS-PHASE, TRIETHYLPHOSPHINE OXIDE, TRANSFER EQUILIBRIUM, MOLECULAR-STRUCTURE, BRONSTED ACIDS, ISOTOPE

    Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

ID: 94249563