Infrared spectra of CH3–MH, CH3–M, and CH3–MH− prepared via methane activation by laser-ablated Au, Ag, and Cu atoms
作者:Han-Gook Cho、Lester Andrews
DOI:10.1039/c0dt01827a
日期:——
Methane activation by laser-ablated, excited Group 11 metal atoms has been carried out, leading to generation of CH3âMH, CH3âM, and CH3âMHâ, which are identified in the product infrared spectra on the basis of isotopic shifts and correlation with DFT calculated frequencies. The products reveal that CâH insertion by excited Au, Ag, and Cu readily occurs, and subsequent hydride-detachment or electron addition also follows. Each type of product has similar photochemical properties regardless of the metal. DFT computed energies reveal facile hydride dissociation and high electron affinities for the insertion complexes. The methyl metal species have the shortest CâM bonds, consistent with their highest calculated effective bond order, and the CH3âMH complexes have higher electron affinities than the metal atoms.
通过激光溅射、激发态的第11族金属原子对甲烷进行活化反应,生成了CH3–MH、CH3–M和CH3–MH',这些产物在红外光谱中根据同位素位移和与DFT计算频率的相关性得到了鉴定。产物表明,激发态的金、银和铜能够容易地进行C–H插入,随后发生氢化物脱离或电子添加。每种类型的产物都具有相似的光化学性质,不受金属种类的影响。DFT计算的能量表明,插入复合物的氢化物解离容易发生,且具有较高的电子亲和性。甲基金属物种的C–M键最短,与其计算出的最高有效键级一致,而CH3–MH复合物的电子亲和性高于金属原子。