Femtosecond spectroscopy of solvated electrons from sodium-ammonia-d3 solutions: temperature jump versus local density jump.
Femtosecond spectroscopy of solvated electrons from sodium-ammonia-d3 solutions: temperature jump versus local density jump.
复制标题
钠-氨-d3 溶液中溶剂化电子的飞秒光谱：温度跳跃与局部密度跳跃。
DOI：
10.1063/1.2965818
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
P. Vöhringer
中科院分区：
文献类型：
--
作者：
J. Lindner;A. Unterreiner;P. Vöhringer
利用飞秒时间分辨近红外光谱研究了钠-氨-d3溶液中溶剂化电子的弛豫动力学。实验泵浦探测数据揭示了脉宽限制泵浦诱导的氨化电子的吸收光谱的红移和随后的较慢的蓝移在大约200 fs的时间尺度上。的spectrotemporal响应解释使用非绝热弛豫机制的腔束缚的溶剂化电子在凝聚相。特别是，我们开发了一个本地的密度跳跃模型，追溯到一个序列的泵引起的腔膨胀由于泡利排斥和随后的腔收缩后，非绝热返回的电子回到其基态的动态谱。使用现有的热力学数据的溶剂和实验的温度和密度依赖的吸收光谱的金属-氨溶液中，整体增加25%的溶剂腔内的颗粒间距离粗略估计。将密度跳跃模型与我们先前提出的温度跳跃模型进行了比较，研究了金属-NH（3）溶液的飞秒弛豫动力学。
The relaxation dynamics of solvated electrons from sodium-ammonia-d3 solutions was studied by femtosecond time-resolved near-infrared spectroscopy. The experimental pump-probe data reveal a pulse-width limited pump-induced redshift of the absorption spectrum of the ammoniated electron and a subsequent slower blueshift on a time scale of roughly 200 fs. The spectrotemporal response is interpreted using the nonadiabatic relaxation mechanism for cavity-bound solvated electrons in condensed phases. In particular, we develop a local density-jump model, which traces the dynamic spectrum back to a sequence of a pump-induced cavity expansion due to Pauli repulsion and a succeeding cavity contraction upon nonadiabatic return of the electron back to its ground state. Using the existing thermodynamic data of the solvent and experimental temperature and density-dependent absorption spectra of metal-ammonia solutions, an overall increase in the interparticle distance within the solvent cavity of 25% is crudely estimated. The density-jump model is compared to the temperature-jump model we proposed previously for the femtosecond relaxation dynamics of metal-NH(3) solutions.