Raman spectra of water

De Santis A, Sampoli M, Mazzacurati V and Ricci M A 1987 Raman spectra of water in the translational region Chem. Phys. Lett. 133 381-4... 

A straightforward experimental estimate of best-case prediction limits can be made by inspecting the spectrum of an analyte dissolved in water with no other spectral interferents present. Figure 16.5 shows Raman spectra of water and dissolved glucose in water, both obtained in 60s in a cuvette-based epi-Raman setup with 435 mW of 830 nm excitation power. In both cases, an... 

Now we shall point out on an experimental confirmation concerning the role of a cooperative motions in formation of the R-band in water. In a recent paper [62] it was inferred from an isotope shift of the R-band that the oscillations to this band are stipulated by molecules deformations. Next, in view of work [63], where the Raman spectra of water substituted with respect to hydrogen and oxygen were studied, one can conclude that the isotope shift is greater for the oxygen substitution. This result means that the oscillations pertinent to the... 

Fig. 8 (a) Infrared and (b) Raman spectra of water.5oiub.e EG Inset shou, photographs of. er-soluble (H.O) and PEG-functionalized EG dispersed in water (PEG). 

They provide a correct short-time description of dynamical processes. They therefore contrast to expansions around inherent structures which are the configurations corresponding to local potential minima obtained by quenching instantaneous system configurations. The results of these two approaches show marked differences as has been demonstrated for the case of low frequency Raman spectra of water. ... 

The low-fiequency Raman spectra of water and aqueous solution are well fitted by a simple model which is a superposition of one relaxation mode and two damped oscillator modes. The dynamical aspect of liquid water and water in aqueous solutions can be characterized by the fitting analysis of these low-lying modes. 

A. De Santis, R. Frattini, M. Sampoli, V. Mazzacurati, M. Nardone, and M. A. Ricci. Raman spectra of water in the translational and librational regions. I. Study of the depolarization ratios. Molec. Phys., 67 1199-1212 (1987). 

The VIB fraction, containing 3CM-5% of water molecules, comprises a dimer. Time variation (vibration) of HB lengths and directions is of interest in this work, since it determines the dielectric and Raman spectra of water in the vicinity of the T-band. The dimer vibration and its response are ruled by mechanisms b-d. 

Woolley, R, B.J. Keely, and R.E. Hester (1996). Surface-enhanced resonance Raman spectra of water-insoluble tetraphenylporphyrin and chlorophyll a on silver hydrosols with a dioxane molecular spacer. Chem. Phys. Lett. 258, 501. 

Figure 29.8 Raman spectra of water at different temperatures. The isosbestic point supports a model involving two states. Source C D Arrigo, C Maisana,... 

Raman spectra of water have been intensively studied in the low-frequency region. References are found in previously mentioned reviews [4,5] and these results will not be discussed in detail, but I will try to highlight some of the aspects I find interesting in context of the biological importance of water. 

T. Okada, K. Komatsu, T. Kawamoto, T. Yamanaka, H. Kagi, Pressure response of Raman spectra of water and its implication to the change in hydrogen bond interaction. Spectrochimica Acta A 61(10), 2423-2427 (2005)... 

Raman spectra of water solutions of formaldehyde also show the. substantial or complete absence of monomeric imhydrated formaldehyde. As Nielsen points out, four investigators of the Ramjm spectra of aqueous formaldehyde, following different methods of procedum, di cw the unanimous conclusion that this solution cannot give rise to the fundamental frequencies of the simple formaldehyde molecule, CHjO. According to Hibben , the principle lines of the Raman spectra for formaldehyde solution correspond both in intensity and frequency to those of ethylene glycol rather than to those of an aliphatic aldehyde. 

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