Physics Department, University of California at Berkeley, Berkeley, California 94720, USA.
J Am Chem Soc. 2009 Mar 4;131(8):2790-1. doi: 10.1021/ja809497y.
Phase-sensitive sum-frequency vibrational spectroscopy (PS-SFVS) has been used to probe the isotopically diluted water/vapor interfaces in the spectral regions of OD (2200-2800 cm(-1)) and OH (3000-3800 cm(-1)) stretches. The experimentally measured Im chiS(2) spectra, where chiS(2) is the surface nonlinear susceptibility, permit direct characterization of resonances of the interfaces. The Im chiS(2) spectrum of the HDO/vapor interface that is intrinsically simpler to analyze can be deduced from the result of isotopic dilution. It exhibits in the bonded-OH region a broad band comprising two parts with opposite signs, in contrast to those deduced earlier from fitting of the |chiS(2)|2 spectra and those calculated by MD simulation, but consistent with that obtained for the H2O/vapor interface.
相位敏感和频振动光谱（PS-SFVS）已被用于探测 OD（2200-2800 cm(-1)) 和 OH（3000-3800 cm(-1))伸缩带中同位素稀释水/蒸汽界面。实验测量的 Im chiS(2)谱，其中 chiS(2)是表面非线性磁化率，允许直接表征界面的共振。从同位素稀释的结果可以推断出 HDO/蒸汽界面固有更简单的 Im chiS(2)谱。它在键合-OH 区域表现出一个由两个具有相反符号的部分组成的宽带，与以前从 |chiS(2)|2 谱拟合和 MD 模拟计算得出的部分相反，但与 H2O/蒸汽界面的结果一致。
