On the cluster composition of supercritical water combining molecular modeling and vibrational spectroscopic data.
Résumé
The present study is aimed at a detailed anal. of supercrit. H2O structure based on the combination of exptl. vibrational spectra as well as mol. modeling calcns. of isolated H2O clusters. The authors propose an equil. cluster compn. model where supercrit. H2O is considered as an ideal mixt. of small H2O clusters (n = 1-3) at the chem. equil. and the vibrational spectra are expected to result from the superposition of the spectra of the individual clusters, Thus, it was possible to ext. from the decompn. of the midinfrared spectra the evolution of the partition of clusters in supercrit. H2O as a function of d. The cluster compn. predicted by this model is quant. consistent with the near IR and Raman spectra of supercrit. H2O analyzed using the same procedure. The authors emphasize that such methodol. could be applied to det. the portion of cluster in H2O in a wider thermodn. range as well as in more complex aq. supercrit. solns. (c) 2010 American Institute of Physics. [on SciFinder(R)]