Raman investigation of the temperature dependence of the bending .nu.2 and combination .nu.2 + .nu.L bands from liquid water

Ultrafast conversions between hydrogen bonded structures in liquid water observed by femtosecond x-ray spectroscopy

“…A recent xray study using static methods reports micro-heterogeneity due to two types of competing water structures 35 similar to ideas first put forward by Röntgen and others 36 and in line with Raman spectroscopic studies. 37 In such a model, the transients in Fig. 3 would follow the equilibration of the relative abundances of the competing structural species created by an impulsive energy increase with an associated conversion rate constant of 1.4 ps -1 .…”

Temperature dependence of vibrational relaxation of the OH bending excitation in liquid H2O

“…Figure 2 shows the linear absorption spectrum of liquid H 2 O for different temperatures, measured by an FTIR spectrometer. Upon temperature elevation, the OH bending fundamental transition band slightly shifts to lower frequency with its linewidth narrowed [16]. A librational absorption background extending up to the OH bending band decreases with temperature.…”

“…The OH bending absorption band exhibits the maximum at 1645 cm À1 with the FWHM width of about 90 cm À1 and displays a pronounced asymmetry towards low frequencies. The asymmetry of the band has been attributed to a superposition of the absorption of fully and partially hydrogen bonded molecules [16]. A weak band centered at 2150 cm À1 is the combination tone of the OH bending and librational modes.…”

Quantum rigid dipole in a permanent electric field. II. Model of librational motion in liquid water and ice Ih: Preliminary results

“…The basic structural unit of the V-structure is a tetrahedron consisting of five water molecules [l, 3,6,7] (see Fig. l), although the existence of trigonally coordinated structures cannot be ruled out [8,9].…”

“…and U p . Within the solitonic model of the orientational defect [25], its "cornerstone" is the so-called free OH group [6][7][8]251.…”