Eftekhari-Bafrooei Ali, Borguet Eric
Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA.
J Am Chem Soc. 2009 Sep 2;131(34):12034-5. doi: 10.1021/ja903340e.
The effect of the structuring of interfacial water, induced by surface charge, on the ultrafast vibrational dynamics of the O-H stretch in the hydrogen bonded spectral region was studied at the H(2)O/fused silica interface. At high pH, where the electric field resulting from deprotonation of silanol groups polarizes several layers of water molecules, fast vibrational dynamics similar to the dynamics of bulk water is observed. At the neutral surface, where the structural ordering of interfacial water and the thickness of interfacial water are smaller than those at the charged surface, the vibrational lifetime of the O-H stretch becomes more than two times longer (T(1) approximately 570 fs). The longer vibrational lifetime is a result of reduced intermolecular coupling resulting from incomplete solvation of the interfacial water species.
研究了在H(2)O/熔融石英界面处，由表面电荷引起的界面水结构对氢键光谱区域中O-H伸缩振动超快动力学的影响。在高pH值下，硅醇基团去质子化产生的电场使几层水分子极化，观察到与体相水动力学相似的快速振动动力学。在中性表面，界面水的结构有序性和界面水的厚度小于带电表面，O-H伸缩振动的振动寿命延长两倍多（T(1)约为570飞秒）。较长的振动寿命是由于界面水物种不完全溶剂化导致分子间耦合降低的结果。
