A combined spectroscopic and computational study of gas-phase Au+(CH4) n (n = 3-8) complexes reveals a strongly-bound linear Au+(CH4)2 core structure to which up to four additional ligands bind in a secondary coordination shell. Infrared resonance-enhanced photodissociation spectroscopy in the region of the CH4 a 1 and t 2 fundamental transitions reveals essentially free internal rotation of the core ligands about the H4C-Au+-CH4 axis, with sharp spectral features assigned by comparison with spectral simulations based on density functional theory. In separate experiments, vibrationally-enhanced dehydrogenation is observed when the t 2 vibrational normal mode in methane is excited prior to complexation. Clear infrared-induced enhancement is observed in the mass spectrum for peaks corresponding 4u below the mass of the Au+(CH4) n=2,3 complexes corresponding, presumably, to the loss of two H2 molecules.

中文翻译：

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Au +（CH4）n配合物的红外光谱和振动增强的CH活化反应。

气相金（CH4）n（n = 3-8）配合物的光谱和计算研究相结合，揭示了强结合的线性Au +（CH4）2核心结构，在二级配位壳中最多可结合四个配体。CH4a 1和t 2基本跃迁区域的红外共振增强光解离光谱显示，核心配体基本上围绕H4C-Au + -CH4轴自由旋转，并通过与基于密度的光谱模拟进行比较而赋予了鲜明的光谱特征功能理论。在单独的实验中，在络合之前激发甲烷中的t 2振动正态模时，观察到振动增强的脱氢。在质谱图中观察到明显的红外线诱导的增强，对应于Au +（CH4）n = 2的质量以下4u的峰，