Kelley Anne Myers, Leng Weinan, Blanchard-Desce Mireille
Department of Chemistry, Kansas State University, Willard Hall, Manhattan, KS 66506-3701, USA.
J Am Chem Soc. 2003 Sep 3;125(35):10520-1. doi: 10.1021/ja036570r.
Resonance hyper-Raman spectra have been obtained using 1064 nm excitation for several electron donor-acceptor-substituted, pi-conjugated "push-pull" molecules that have large second harmonic hyperpolarizabilities. The hyper-Raman spectra are nearly identical to the resonance Raman spectra measured with 532 nm excitation. This indicates that both the second harmonic hyperpolarizability and the linear absorption are dominated by the same, single electronic transition that is both one- and two-photon allowed. Comparison of resonance Raman and resonance hyper-Raman spectra is proposed as an experimental test of the common two-electronic-state model for the first hyperpolarizability.
利用1064 nm激发光,获得了几种具有大二阶谐波超极化率的电子供体-受体取代的π共轭“推-拉”分子的共振超拉曼光谱。这些超拉曼光谱与用532 nm激发光测得的共振拉曼光谱几乎相同。这表明二阶谐波超极化率和线性吸收均由同一个单电子跃迁主导,该跃迁既是单光子允许的,也是双光子允许的。有人提出将共振拉曼光谱和共振超拉曼光谱进行比较,作为对一阶超极化率的常见双电子态模型的实验检验。