Communication: A rotationally resolved (2OH) overtone band in the water dimer (H2O)2

Abstract

Communication: Determination of the bond dissociation energy (D 0 ) of the water dimer, (H 2 O) 2 , by velocity map

The water dimer I: Experimental characterization

“…Földes et al very recently (2014) reported rotationally resolved spectra of the H 2 O dimer 2 OH (overtone) band in the spectral region 7229-7262 cm −1 [59]. This new report helps to refine the previous assignment of Nizkorodov et al [60].…”

“…The band appearing at 7282 cm −1 remained unassigned. Földes et al observed eight broad features using Fourier transform, tunable diode and quadrupole mass spectrometers coupled with supersonic expansions [59]. Two weak bands appearing at 7233.9 and 7234.4 cm −1 , not listed in Nizkorodov et al's report, were assigned to other H 2 O-containing clusters.…”

Analysis of a remarkable perpendicular band in Kr H2O with origin close to the ν1+ν3 R(0) line in H2O

“…The main features of the experimental part are adapted in this section from our recent report on (H2O)2 [1]. We have used the so-called FANTASIO+ (for "Fourier trANsform, Tunable diode and quAdrupole masS spectrometers Interfaced to a supersOnic expansion"), set-up [17,23] to investigate a supersonic expansion of Kr ("Air Liquide") seeded with H2O ('ultrapure' Milli-Q water, with a resistivity of 18.2 M·cm).…”

“…About 5000 sccm (where sccm denotes cubic centimeter per minute at standard conditions for temperature and pressure) of carrier gas was injected, so that the reservoir (p0) and residual (p ∞ ) pressures were kept constant at 60 kPa and below 2 Pa, respectively, similarly to the previous water dimer experiments [1]. H2O was seeded into the gas stream by passing this time slightly less of the carrier gas through the 30 cm long bubbler filled with liquid H2O than when searching for (H2O)2 (5%) in [1].…”

“…We recently used continuous-wave cavity ring-down spectroscopy (CW-CRDS) to interrogate a rare gas (RG) supersonic expansion seeded with H2O and reported on the observation of the water dimer (H2O)2 [1]. The spectra were recorded around 7245 cm -1 , thus in the 1+3, 2OH excitation range of water, using a DFB diode laser scanning about 30 cm -1 .…”