Ge Aimin, Rudshteyn Benjamin, Zhu Jingyi, Maurer Reinhard J, Batista Victor S, Lian Tianquan
Department of Chemistry, Emory University , Atlanta, Georgia 30322, United States.
Department of Chemistry, Yale University , New Haven, Connecticut 06520, United States.
J Phys Chem Lett. 2018 Jan 18;9(2):406-412. doi: 10.1021/acs.jpclett.7b02885. Epub 2018 Jan 10.
A combination of time-resolved vibrational spectroscopy and density functional theory techniques have been applied to study the vibrational energy relaxation dynamics of the Re(4,4'-dicyano-2,2'-bipyridine)(CO)Cl (Re(CO)Cl) catalyst for CO to CO conversion bound to gold surfaces. The kinetics of vibrational relaxation exhibits a biexponential decay including an ultrafast initial relaxation and complete recovery of the ground vibrational state. Ab initio molecular dynamics simulations and time-dependent perturbation theory reveal the former to be due to vibrational population exchange between CO stretching modes and the latter to be a combination of intramolecular vibrational relaxation (IVR) and electron-hole pair (EHP)-induced energy transfer into the gold substrate. EHP-induced energy transfer from the Re(CO)Cl adsorbate into the gold surface occurs on the same time scale as IVR of Re(CO)Cl in aprotic solvents. Therefore, it is expected to be particularly relevant to understanding the reduced catalytic activity of the homogeneous catalyst when anchored to a metal surface.
时间分辨振动光谱和密度泛函理论技术相结合，用于研究与金表面结合的用于一氧化碳转化为二氧化碳的铼（4,4'-二氰基-2,2'-联吡啶）（羰基）氯（Re(CO)Cl）催化剂的振动能量弛豫动力学。振动弛豫动力学表现出双指数衰减，包括超快的初始弛豫和基态振动状态的完全恢复。从头算分子动力学模拟和含时微扰理论表明，前者是由于CO伸缩模式之间的振动布居交换，后者是分子内振动弛豫（IVR）和电子-空穴对（EHP）诱导的能量转移到金基底中的组合。EHP诱导的从Re(CO)Cl吸附物到金表面的能量转移与Re(CO)Cl在非质子溶剂中的IVR发生在相同的时间尺度上。因此，预计这对于理解均相催化剂锚定在金属表面时催化活性降低的情况特别相关。
