Fonseca Giovana V, Fernandes Gabriel F S, Machado Francisco B C, Ferrão Luiz F A
Instituto de Ciência e Tecnologia da UNIFESP, São José dos Campos, Brazil.
Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos, SP, 12228-900, Brazil.
J Mol Model. 2022 Sep 10;28(10):307. doi: 10.1007/s00894-022-05308-3.
Clusters are physical entities composed of a few to thousands of atoms with capabilities to develop novel materials, like cluster-assembled materials. In this sense, knowing the electronic structure and physicochemical properties of the isolated clusters can be useful to understand how they interact with other chemical species by intermolecular forces, as free, embedded, and saturated clusters, and by intramolecular forces, acting as support clusters. In this way, in the present work, the electronic structure and physicochemical properties of metal oxide nanoclusters (MgO, AlO, SiO, and TiO) were studied by highly correlated molecular quantum chemistry methods. Through the electronic state's characterization, a semiconductor aspect was found for the titania oxide nanocluster (T < 0.8 eV) while the other agglomerates showed a characteristic of insulating material (T > 3.3 eV). From the stability index, the following stability order can be characterized: (SiO) > (AlO) > (MgO) > (TiO). Initial information of intermolecular and intramolecular forces caused by the studied clusters was calculated through the relative electrophilicity index, which classified the (MgO) and (TiO) clusters as the more reactive ones, in which the (MgO) cluster was identified as a nucleophilic species, while the (TiO) cluster as an electrophilic molecule.
团簇是由几个到数千个原子组成的物理实体，具有开发新型材料的能力，如团簇组装材料。从这个意义上说，了解孤立团簇的电子结构和物理化学性质有助于理解它们如何通过分子间力（作为自由、嵌入和饱和团簇）以及分子内力（作为支撑团簇）与其他化学物种相互作用。因此，在本工作中，采用高度相关的分子量子化学方法研究了金属氧化物纳米团簇（MgO、AlO、SiO和TiO）的电子结构和物理化学性质。通过电子态的表征，发现二氧化钛纳米团簇具有半导体特性（T＜0.8 eV），而其他团聚体表现出绝缘材料的特性（T＞3.3 eV）。根据稳定性指数，可以确定以下稳定性顺序：(SiO)＞(AlO)＞(MgO)＞(TiO)。通过相对亲电指数计算了所研究团簇引起的分子间和分子内力的初始信息，该指数将(MgO)和(TiO)团簇归类为反应性更强的团簇，其中(MgO)团簇被确定为亲核物种，而(TiO)团簇为亲电分子。
