Vibrational energy relaxation of the ND-stretching vibration of NH2D in liquid NH3.
Vibrational energy relaxation of the ND-stretching vibration of NH2D in liquid NH3.
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NH2D 在液态 NH3 中的 ND 伸缩振动的振动能量弛豫
DOI：
10.1039/c2cp41382e
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Schwarzer
中科院分区：
文献类型：
--
作者：
Schäfer;Kandratsenka;Vöhringer;Schroeder;Schwarzer
用分子动力学模拟方法研究了NH_3溶液中NH2D分子的第一激发伸缩模的振动能弛豫。在量子经典Landau-Teller理论的框架下，计算了分子间和分子内能量转移的速率常数。在273K，氨气浓度为0.642 g cm−3的条件下，计算得到的τ的拉伸寿命为9.1ps，与实验值8.6ps符合得很好。占能量转移52%的主要弛豫通道涉及分子内向伞形模第一激发态的跃迁。这两种状态之间的能量差被溶剂的近共振弯曲振动吸收。对ND拉伸寿命不太重要的是直接跃迁到基态，以及通过NH2D弯曲模式贡献23%的分子内弛豫。我们的计算表明，实验观察到的τ的弱密度依赖性是由于ND伸展伞状能隙和溶剂接受模之间的共振失谐所致，这抵消了驰豫速率随密度线性增加的预期。
The vibrational energy relaxation from the first excited ND-stretching mode of NH2D dissolved in liquid NH3 is studied using molecular dynamics simulations. The rate constants for inter- and intramolecular energy transfer are calculated in the framework of the quantum-classical Landau–Teller theory. At 273 K and an ammonia density of 0.642 g cm−3 the calculated ND-stretch lifetime of τ = 9.1 ps is in good agreement with the experimental value of 8.6 ps. The main relaxation channel accounting for 52% of the energy transfer involves an intramolecular transition to the first excited state of the umbrella mode. The energy difference between both states is taken up by the near-resonant bending vibrations of the solvent. Less important for the ND-stretch lifetime are both the direct transition to the ground state and intramolecular relaxation via the NH2D bending modes contributing 23% each. Our calculations imply that the experimentally observed weak density dependence of τ is caused by detuning the resonance between the ND-stretch–umbrella energy gap and the solvent accepting modes which counteracts the expected linear increase of the relaxation rate with density.
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影响因子：
62.1
作者：
R. Rey;K. B. Møller;J. Hynes
通讯作者：
R. Rey;K. B. Møller;J. Hynes
金属胺溶液还原：在合成和结构测定中的应用
DOI：
10.1039/qr9581200017
发表时间：
1958
期刊：
Quarterly Reviews, Chemical Society
影响因子：
--
作者：
A. Birch;H. Smith
通讯作者：
H. Smith
影响因子：
4.4
作者：
J. K. Brown;C. Harris;J. Tully
通讯作者：
J. Tully
影响因子：
4.4
作者：
M. Ricci;M. Nardone;F. Ricci;C. Andreani;A. Soper
通讯作者：
M. Ricci;M. Nardone;F. Ricci;C. Andreani;A. Soper
DOI：
10.1021/jp046711r
发表时间：
2004-12
期刊：
The journal of physical chemistry. A
影响因子：
--
作者：
T. Steinel;J. Asbury;Junrong Zheng;M. Fayer
通讯作者：
T. Steinel;J. Asbury;Junrong Zheng;M. Fayer