Identification of a Stable Ozonide Ion Bound to a Single Cadmium Site within the Zeolite Cavity
Identification of a Stable Ozonide Ion Bound to a Single Cadmium Site within the Zeolite Cavity
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DOI：
10.1021/acs.jpcc.1c09277
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发表时间：
2022-01
期刊：
影响因子：
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通讯作者：
Akira Oda;K. Sawabe;T. Ohkubo;Y. Kuroda
中科院分区：
文献类型：
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作者：
Akira Oda;K. Sawabe;T. Ohkubo;Y. Kuroda
分子金属氧化物是多种氧化反应的关键中间体。虽然原子氧配体和分子氧配体是众所周知的，但三原子氧配体（臭氧）由于其不稳定性而非常有限。在这里，我们报道了一种稳定的臭氧化镉物种的成功制备和表征。我们的方法使用了沸石孔内带负电荷的局部环境，这使得我们即使在室温下也能分离出单一的臭氧镉作为反阳离子。它的状态表现为与低温惰性元素基质系统相似的振动级数。密度泛函理论计算确定了最低能量的几何形状为侧对[CdII（O3 -•）]+，具有c2v对称性。该模型在300 K从头算分子动力学模拟中是稳定的，合理地解释了实验观察到的[CdII（O3 -•）]+的异常稳定性。O3-a1→cd -5s给能轨道相互作用是形成稳定的CdII - （O3 -•）键的驱动力。沸石晶格在提高镉离子的酸性和稳定供体相互作用方面起着关键作用，但限制了o3加合物作为假无臭氧离子。本工作的发现将适用于设计新的金属臭氧化合物。
Molecular metal oxides are invoked as the key intermediate in a variety of oxidative reactions. Although an atomic oxygen ligand and molecular O2ligands are well known, the triatomic oxygen ligand (ozonide) is very limited due to its instability. Here, we report a successful preparation and characterization of stable cadmium ozonide species. Our approach used the negatively charged local environments within the zeolite pore, which allowed us to isolate the single cadmium ozonide species as the counter cation even at room temperature. Its state was characterized by vibronic progressions closely similar to those observed in the cryogenic inert-element matrix system. Density functional theory calculations determined the lowest-energy geometry as the side-on [CdII(O3–•)]+havingC2vsymmetry. This model was stable within the ab initio molecular dynamics simulation at 300 K, rationalizing the abnormal stability of [CdII(O3–•)]+observed experimentally. The O3-a1→ Cd-5s-donation orbital interaction was the driving force for the formation of the stable CdII–(O3–•) bond. The zeolite lattice plays a pivotal role in the enhancement of the acidity of the cadmium ion and stabilizes the donation interaction but constrains the O3adduct as a pseudo-free ozonide ion. The findings in the present work will be applicable for designing new metal ozonide compounds.