Área de Física Atómica Molecular Aplicada (FAMA), CBI, Universidad Autónoma Metropolitana-Azcapotzalco, Av. San Pablo 180, Col. Reynosa Tamaulipas, México, D. F. 02200, México.
J Chem Phys. 2010 Dec 28;133(24):244306. doi: 10.1063/1.3521269.
Nitrous oxide (N(2)O) is an intermediate compound formed during catalysis occurring in automobile exhaust pipes. Atomic Au in its ground state is unable to react with N(2)O, however, several Au excited states are bound to N(2)O, but not all of these states are able to activate N(2)O bonds. In this work, N(2)O capture and activation by a single Au atom are studied considering Au in the ground and excited states with multiplicities = 2, 4 and 6. The Au + N(2)O reactions are studied at multireference second-order perturbation level of theory using C(s) symmetry. The AuN(2)O ((4)A', (4)A'', (6)A' and (6)A'') adducts are spontaneously created from Au excited states. From these complexes, only the (4)A', (6)A' and (6)A'' states exhibit N(2)O activation reaction paths yielding N(2,) NO and O atoms as end products when N(2)O approaches Au excited states side-on. Cations both ground and excited states, capture N(2)O although only the Au(+) ((5)A') + N(2)O ((1)Σ(+)) → NAuNO(+) ((5)A') reaction (for the end-on and side-on approaches) shows N(2)O activation with N-N bond breaking. In the case of Au anions, the ground state and most of the excited states capture N(2)O and activation takes place according to Au(-) ((3)A', (5)A', (5)A'') + N(2)O ((1)Σ(+)) → AuO(-) ((3)A', (5)A', (5)A'') + N(2)(g) for the N(2)O end-on approach by the oxygen atom. The reaction paths show a metal-gas dative covalent bonding character. Mulliken charge population analysis obtained for the active states shows that the binding is done through charge donation and retro-donation between the metal and the N(2)O molecule.
一氧化二氮（N(2)O）是汽车排气管中催化作用形成的中间化合物。基态的原子 Au 不能与 N(2)O 反应，但有几个 Au 激发态与 N(2)O 结合，但不是所有这些激发态都能激活 N(2)O 键。在这项工作中，研究了基态和激发态的单个 Au 原子对 N(2)O 的捕获和激活，考虑了多重性 = 2、4 和 6 的 Au。使用 C(s) 对称，在多参考二级微扰理论水平上研究了 Au + N(2)O 反应。AuN(2)O((4)A'、(4)A''、(6)A'和(6)A'')加合物是从 Au 激发态自发形成的。在这些复合物中，只有 (4)A'、(6)A'和 (6)A''状态表现出 N(2)O 激活反应路径，当 N(2)O 侧向接近 Au 激发态时，产生 N(2,)NO 和 O 原子作为终产物。无论是基态还是激发态的阳离子，都能捕获 N(2)O，尽管只有 Au(+)((5)A')+N(2)O((1)Σ(+))→NAuNO(+)((5)A')反应（对于端对和侧对方法）显示出 N(2)O 激活与 N-N 键断裂。对于 Au 阴离子，基态和大多数激发态都能捕获 N(2)O，并根据 Au(-)((3)A'、(5)A'、(5)A'')+N(2)O((1)Σ(+))→AuO(-)((3)A'、(5)A'、(5)A'')+N(2)(g)进行反应，其中 N(2)O 通过氧原子进行端对。反应路径显示出金属-气体 dative 共价键的特征。对于活性态，Mulliken 电荷分布分析表明，结合是通过金属和 N(2)O 分子之间的电荷供体和回供体实现的。
