Stretching ofcis-formic acid: warm-up and cool-down as molecular work-out

Abstract

The spectroscopic data base forcis-formic acid is considerably extended to make it fit for experimental benchmarking of vibrational calculation tools.

Three-dimensional docking of alcohols to ketones: an experimental benchmark based on acetophenone solvation energy balances

“…† This is particularly important for the M06-2X functional due to its grid sensitivity. 31,32 Thermal corrections were neglected, given the very low (approx. 10 K) rotational temperature, the mode-dependent vibrational temperatures and a conformational temperature on the order of 100 K. The zero-point vibrational energy (ZPVE) was treated harmonically.…”

Soft experimental constraints for soft interactions: a spectroscopic benchmark data set for weak and strong hydrogen bonds

“…On the other hand, the experimental wavenumber of the lowest mode of the metastable cis FA monomer 71 is known to 8 significant digits 72 and no theoretical model will be able to come close to this accuracy in the foreseeable future. 73 For benchmarking purposes, it is more meaningful to provide a number of FA monomer modes 31,74 to, say, 1% accuracy and an experimental binding energy of the formic acid dimer. 36 It is essential that these data refer to molecules in the gas phase, rather than in matrix isolation, 75,76 because matrix shifts will likely be of similar size and unknown direction as residual errors in modern quantum chemical methods.…”

Vibrational states of deuterated trans- and cis-formic acid: DCOOH, HCOOD, and DCOOD

“…Therefore, the observation of the cis form in the gas phase requires a long absorption path (and no band-overlap) or more elaborate techniques such as demonstrated recently by Meyer and Suhm. 7 Another approach to detecting the cis-form involves using rare-gas matrix isolation, and this has been the primary method used for the experimental study of the cis form. However, this method induces environmental effects on the vibrational spectrum in going from the gas phase to the matrix.…”

“…Moreover, the observed shifts in peak positions are dependent on the vibrational state and, thus, do not permit a systematic comparison to gas-phase theoretical results as shown by Meyer and Suhm. 7 Therefore, if one wishes to benchmark theoretical approaches for obtaining vibrational energies, gasphase measurements must be conducted directly for both isomers and their isotopologues.…”