Observation of the rotational spectra of van der Waals complexes by free jet absorption millimeter wave spectroscopy: pyridine-argon

Jet-Cooled Rotational Spectra and Ab Initio Investigations of the Tetrahydropyran-Water System

“…[36] Experimental section Free-jet absorption millimeter-wave spectroscopy: The Stark-and pulsemodulated free-jet absorption millimeter-wave spectrometer used in this study has been described elsewhere. [18,19] The adducts were formed by allowing argon to flow, at room temperature and a pressure of ca. 0.7 bar, over a solution of THP and water in a 2:1 molar ratio.…”

Intermolecular Hydrogen Bonding between Water and Pyrazine

“…[18] Complexes were formed in a stream of argon saturated with water at room temperature and a pressure of about 2 bar that passed over samples of PRZ heated to about 40 8C. The mixture, at a stagnation pressure of 0.5 bar, was expanded to about 5 Â 10 À3 mbar through a pulsed nozzle (repetition rate 5 Hz) with a diameter of 0.35 mm, which produced an estimated ªrota-tionalº temperature of about 10 K. All samples involved commercial materials utilized without further purification.…”

“…Prz´´´H 18 OH Prz´´´DOH Prz´´´DOD 0 (5) equilibrium values. The larger j b j value for the hydrogen atom not involved in the hydrogen bond indicates that this atom does not lie along the a axis, but always lies in the ab plane.…”

The C-F⋅⋅⋅H-C “Anti-Hydrogen Bond” in the Gas Phase: Microwave Structure of the Difluoromethane Dimer

“…[4,16] The dimer was formed by expanding a mixture of about 5 mol % DFM in argon (or neon) at room temperature and at a pressure of approximately 0.8 bar to about 5 Â 10 À3 mbar through a pulsed nozzle (repetition rate 5 Hz) with a diameter of 0.35 mm. An estimated ªrotationalº temperature of about 10 K was reached.…”

“…[2] This kind of data is available for O-H´´´O, O-H´´´N, O-H´´´S, O-H´´´p, N-H´´´N, N-H´´´O, X-H´´´N, and X-H´´´O linkages (X F, Cl, CN). [3] A few years ago we introduced free jet millimeter wave absorption spectroscopy for the study of molecular complexes, [4] and obtained the first data from high-resolution spectroscopy on the solvation of ethers, [5] cyclic amines, [6] and diazines [7] through the study of the 1/1 complexes with water. Recently, while investigating the complex of difluoromethane (DFM) with water, [8] we noticed, besides the spectrum of DFM ± H 2 O, a set of evenly spaced m a -R-branch lines.…”