Vibrational spectra of water solutions of azoles from QM/MM calculations: effects of solvation

J Phys Chem A. 2012 Oct 18;116(41):10160-71. doi: 10.1021/jp3045059. Epub 2012 Oct 3.

Abstract

Using microsolvation models and mixed quantum/classical ab initio molecular dynamics simulations, we investigate the vibrational properties of two azoles in water solution: pyrazole and oxazole. The effects of the water-azole hydrogen bonding are rationalized by an extensive comparison between structural parameters and harmonic frequencies obtained by microsolvation models. Following the effective normal-mode analysis introduced by Martinez et al. [Martinez et al., J. Chem. Phys. 2006, 125, 144106], we identify the vibrational frequencies of the solutes using the decomposition of the vibrational density of states of the gas phase and solution dynamics. The calculated shifts from gas phase to solution are fairly in agreement with the available experimental data.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Azoles / chemistry*
  • Hydrogen Bonding
  • Molecular Dynamics Simulation*
  • Oxazoles / chemistry*
  • Pyrazoles / chemistry*
  • Quantum Theory*
  • Solutions
  • Spectrophotometry, Infrared
  • Spectrum Analysis, Raman
  • Water / chemistry*

Substances

  • Azoles
  • Oxazoles
  • Pyrazoles
  • Solutions
  • Water
  • pyrazole