Density Functional Theory Based Studies on the Nature of Raman and Resonance Raman Scattering of Nerve Agent Bound to Gold and Oxide-Supported Gold Clusters: A Plausible Way of Detection

作者：Majumdar D; Roszak Szczepan; Leszczynski Jerzy^*

来源：Journal of Physical Chemistry A, 2010, 114(12): 4340-4353.

DOI：10.1021/jp910472c

A detailed theoretical investigation has been carried out at the density functional level of theories to investigate the nature of Raman intensities of the -P = O stretching mode of a model nerve agent DFP (diisopropylfluorophosphate) when bound to different gold (Au-8, Au-20) and oxide-supported gold (MgO center dot center dot center dot Au-4, CaO center dot center dot center dot Au-4, TiO2 center dot center dot center dot Au-4, Al2O3 center dot center dot center dot Au-4, M16O16 center dot center dot center dot Au-8, and [M16O15 center dot center dot center dot Au-8](2+), M = Ca, Mg) clusters. All of these clusters and the DFP-bound clusters are fully optimized, and the computed energetics shows that DFP attaches itself weakly to these clusters. The normal Raman spectra calculations on these clusters show that there is substantial enhancement of the -P = O stretching mode of DFP compared to file isolated species. This enhancement has been found to be due to the polarization of the -P = O bond of DFP when bound to the clusters. Significant enhancement in intensity has been observed in the case of Au-n center dot center dot center dot DFP (n = 8, 20), M16O16 center dot center dot center dot Au-8 center dot center dot center dot DFP, and [M16O15 center dot center dot center dot Au-8](2+)center dot center dot center dot DFP (M = Ca, Mg) clusters. The resonance Raman calculations on the Au-n center dot center dot center dot DFP (n = 8, 20) reveals that this enhancement could be made quite large and selective, which is a feature that is unique to the nerve agents and could be used as a property for detecting them.

• 出版日期2010-4-1