Halogens in Acetophenones Direct the Hydrogen Bond Docking Preference of Phenol via Stacking Interactions

Phenol is added to acetophenone (methyl phenyl ketone) and to six of its halogenated derivatives in a supersonic jet expansion to determine the hydrogen bonding preference of the cold and isolated 1:1 complexes by linear infrared spectroscopy. Halogenation is found to have a pronounced effect on the docking site in this intermolecular ketone balance experiment. The spectra unambiguously decide between competing variants of phenyl group stacking due to their differences in hydrogen bond strength. Structures where the phenyl group interaction strongly distorts the hydrogen bond are more difficult to quantify in the experiment. For unsubstituted acetophenone, phenol clearly prefers the methyl side despite a predicted sub-kJ/mol advantage that is nearly independent of zero-point vibrational energy, turning this complex into a challenging benchmark system for electronic structure methods, which include long range dispersion interactions in some way.

Halogens in Acetophenones Direct the Hydrogen Bond Docking Preference of Phenol via Stacking Interactions

Phenol is added to acetophenone (methyl phenyl ketone) and to six of its halogenated derivatives in a supersonic jet expansion to determine the hydrogen bonding preference of the cold and isolated 1:1 complexes by linear infrared spectroscopy. Halogenation is found to have a pronounced effect on the docking site in this intermolecular ketone balance experiment. The spectra unambiguously decide between competing variants of phenyl group stacking due to their differences in hydrogen bond strength. Structures where the phenyl group interaction strongly distorts the hydrogen bond are more difficult to quantify in the experiment. For unsubstituted acetophenone, phenol clearly prefers the methyl side despite a predicted sub-kJ/mol advantage which is nearly independent of zero point vibrational energy, turning this complex into a challenging benchmark system for electronic structure methods which include long range dispersion interactions in some way.

Gas-phase hydration of nopinone: the interplay between theoretical methods and experiments unveils the conformational landscape

The structure of microsolvated nopinone formed in the supersonic jet expansion is investigated in the gas phase. The rotational spectra of nopinone-(H2O)n (n=1,2,3) were analysed by means of Fourier transform...

Conformational changes in hydroxyl functional group upon hydration: the case study of Endo Fenchol

The hydration of endo-fenchol has been studied in the gas phase using a combination of Fourier transform microwave spectrometer coupled to a supersonic jet expansion and theoretical calculations in the...

Potential energy surface of fluoroxene: experiment and theory

The potential energy surface (PES) of the general anesthetic fluoroxene was probed in a supersonic jet expansion using broadband CP-FTMW spectroscopy and theoretical calculations.

OH-stretch overtone of methanol: empirical assignment using a two temperature technique in a supersonic jet

Application of two-temperature analysis in combination with GSCD is demonstrated to provide reliable assignments in methanol high resolution overtone spectra measured in supersonic jet expansion.

A New Liquid Droplet Laser Desorption Source Combined with Supersonic Jet Expansion: Application to Phenol and its Water Clusters

We have developed a new laser source, for the spectroscopy of nonvolatile molecules in gas phase. It is based on a laser induced liquid bead ion desorption source (LILBID) combined with a supersonic beam. The cold molecules produced with this technique are sampled with Resonant Two Photon Ionization spectroscopy (R2PI) to measurement of the gas phase optical spectra. LILBID allows to bring nonvolatile molecule from liquid phase (out of a droplet) into gas phase, by means of multi photon ablation with IR photons exciting the vibrations of the solvent. Phenol and its different water clusters have been used as an example to demonstrate the method and to standardise the new experimental setup. The recorded R2PI spectral data of phenol monomer and its different water clusters obtained from this laser desorption technique are in very good agreement with the previously published data. This technique opens a new door for the measurement of molecules under microsolvation and potentially for