Infrared molecular beam depletion spectroscopy of size-selected methanol clusters

Laser Spectroscopy of Helium Solvated Clusters of Methanol and Methanol-Water in the Symmetric Methyl Stretching Band

Mid-infrared spectra of methanol and methanol-water clusters have been investigated in the symmetric CD₃ stretching band of CD₃OH and CD₃OD. We find that the position of this band provides a useful signature of the general type of hydrogen-bonded cluster it is associated with. Our results are consistent with those previously reported in the OH stretching region (Sulaiman, M. I.; Yang, S.; Ellis, A. M. J. Phys. Chem. A 2017, 121, 771-776) in that methanol clusters from the trimer to the pentamer are cyclic and that mixed clusters with one water molecule (and at least two methanol molecules) are also cyclic. We additionally provide evidence that the methanol trimer adopts a chair-like structure (as opposed to bowl-like), that mixed clusters with a larger number of water molecules are also cyclic, and that branched methanol clusters contribute to the depletion signal in larger methanol clusters. We performed double-hybrid DFT calculations which support these interpretations.

Low Temperature Multilayer Adsorption of Methanol and Ethanol on Platinum

Adsorption of methanol and ethanol on the clean Pt (111) surface was studied at temperatures between 80 and 130 K using polarization-modulation infrared reflection absorption spectroscopy (PM-IRRAS). It was shown that adsorption of methanol at 80 K leads to the formation of amorphous solid methanol, and fast crystallization of the amorphous phase occurs upon warming at 100 K. Vapor deposition of methanol at 100 K directly leads to the formation of well-crystallized layers of solid methanol. According to PM-IRRAS, these crystalline layers consist of chains of hydrogen-bonded methanol molecules lying in a plane oriented close to the normal to the platinum surface. Adsorbed methanol is removed completely from platinum after heating to 120 K. Vapor deposition of ethanol at 80 K also leads to the formation of amorphous solid ethanol. However, subsequent warming does not lead to ordering of the adsorption layers, and at 130 K, ethanol is also completely desorbed.

Evidence for Chiral Isomers in the Spectra of Small Size Selected Hydrazine Clusters

New configurations of hydrazine (N