School of Chemistry and Chemical Engineering, South China University of Technology, 381 Wushan Road, Tianhe District, Guangzhou 510640, China.
Dalton Trans. 2013 Aug 21;42(31):11205-11. doi: 10.1039/c3dt50882j.
Aluminum oxide cluster anions are produced by laser ablation and reacted with n-butane in a fast flow reactor. A reflectron time-of-flight mass spectrometer is used to detect the cluster distribution before and after the reactions. Aluminum oxide clusters Al₂O4,6⁻ and Al₃O₇⁻ can react with n-C₄H₁₀ to produce Al₂O4,6H⁻ and Al₃O₇⁻, respectively, while cluster Al₃O₆⁻ reacts with n-C₄H₁₀ to produce both the Al₃O₆H⁻ and Al₃O₆H₂⁻. The theoretical calculations are performed to study the structures and bonding properties of clusters Al₂O4,6⁻ and Al₃O6,7⁻ as well as the reaction mechanism of Al₂O₄⁻ + n-C₄H₁₀. The calculated results show that the mononuclear oxygen-centred radicals (O⁻˙) on Al₂O4,6⁻ and Al₃O₇⁻, and oxygen-centred biradical on Al₃O₆⁻ are the active sites responsible for the observed hydrogen atom abstraction reactivity. Furthermore, mechanism investigation of the O⁻˙ generation in Al₃O₇⁻ upon O₂ molecule adsorption on un-reactive Al₃O₅⁻ is performed by theoretical calculations.
氧化铝团簇阴离子通过激光烧蚀产生，并在快速流动反应器中与正丁烷反应。使用反射飞行时间质谱仪检测反应前后的团簇分布。氧化铝团簇 Al₂O4,6⁻ 和 Al₃O₇⁻ 可以与正丁烷反应，分别生成 Al₂O4,6H⁻ 和 Al₃O₇⁻，而团簇 Al₃O₆⁻ 与正丁烷反应生成 Al₃O₆H⁻ 和 Al₃O₆H₂⁻。通过理论计算研究了团簇 Al₂O4,6⁻ 和 Al₃O6,7⁻ 的结构和键合性质以及 Al₂O₄⁻ + n-C₄H₁₀ 的反应机理。计算结果表明，Al₂O4,6⁻ 和 Al₃O₇⁻ 上的单核氧中心自由基（O⁻˙）和 Al₃O₆⁻ 上的氧中心双自由基是导致观察到的氢原子提取反应性的活性位点。此外，通过理论计算研究了 O₂ 分子在无反应性 Al₃O₅⁻ 上吸附时 Al₃O₇⁻ 中 O⁻˙ 的生成机制。
