Density Functional Study and Normal-Mode Analysis of the Bindings and Vibrational Frequency Shifts of the Pyridine-M (M = Cu, Ag, Au, Cu+, Ag+, Au+, and Pt) Complexes
Density Functional Study and Normal-Mode Analysis of the Bindings and Vibrational Frequency Shifts of the Pyridine-M (M = Cu, Ag, Au, Cu+, Ag+, Au+, and Pt) Complexes
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DOI：
10.1021/jp025970i
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发表时间：
2002-08
影响因子：
2.9
通讯作者：
De‐Yin Wu;B. Ren;Yuxiong Jiang;Xin Xu;Z. Tian
中科院分区：
文献类型：
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作者：
De‐Yin Wu;B. Ren;Yuxiong Jiang;Xin Xu;Z. Tian
40多年来，拉曼光谱和红外光谱被广泛用于研究吡啶在不同表面上的吸附。然而，并没有对所有的振动模式进行令人满意的指认。本文采用密度泛函B3LYP/6-311+G**(对于C，N，H)/LANL2DZ(对于金属)计算了吡啶−金属原子(离子)络合物的中性和阳离子物种。在此基础上，对文献报道的红外光谱和拉曼光谱中自由吡啶的v17a、v3、v5和v18b模的基频进行了新的指认。计算的频移表明，v1、v12和v18a模之间的耦合以及这些模与N−金属(铜、银、金或铂)键之间的耦合取决于N−金属键的强度及其成键性质。V6A振型的基频与振型的频率几乎呈线性关系。
Raman and infrared (IR) spectroscopies have been used extensively to study the adsorption of pyridine on various surfaces for more than 40 years. However, no satisfactory assignment on all the vibrational modes has been achieved. In the present study, density functional theory at the level of B3LYP/6-311+G** (for C, N, H)/LANL2DZ (for metals) has been used for the normal coordinate calculations of the neutral and cationic species of the pyridine−metal atom (ion) complexes. Based on the present calculations, new assignments of the fundamental frequencies for the bands attributed to v17a, v3, v5, and v18b modes of the free pyridine in the reported IR and Raman spectra have been suggested. The calculated frequency shifts indicate that the coupling among v1, v12, and v18a modes and the coupling between these modes and the N−metal (Cu, Ag, Au, or Pt) bond depend on the strength of the N−metal bond and its bonding properties. The fundamental frequency of the v6a mode has a nearly linear relationship with the ch...