| Clusters,which have a defined atomic composition and chemical structure,are ideal models for correlating macroscopic properties and microstructure of matter,also,multinuclear aggregates between atoms,molecules,and macroscopic substances.As an important branch of cluster science,superatoms are of great significance in the fields of simulating the physical and chemical properties of individual atoms to construct a three-dimensional periodic table and designing novel multifunctional nanomaterials.Traditionally,the superatoms are mainly achieved by electron-counting rules(ECR),such as the Jellium model,octet shell closure rule,the 18-electron rule,the Wade-Mingos rule,Hückel’s rules of aromaticity,the isocovalent electron rule,and multiple electron-counting rules,etc.However,there exists obvious limitations in these conventional methodologies because of the necessity for altering cluster intrinsic properties,which is relatively difficult and inconvenient to be controlled experimentally.To overcome such a drawback,external-field strategies for designing superatoms have been developed,recently,such as ligand field,oriented external electric field(OEEF)as well as dual external field.Based on density functional theory(DFT),this paper uses the solvent field to regulate different clusters.We proposed an effective strategy for obtaining external-field-regulated superatom(EFRS),and systematically analyzed the effects of external field on the geometric structure,electronic properties,and catalytic properties of cluster molecules.The major contents and innovations are as follows:(1)By exploring the influence of several different solvents on the properties of pure gold clusters and doped gold clusters,a novel external field,namely the solvent field,is proposed.It is proved that the solvent field can stabilize the cluster and adjust its electronic properties to form a superhalogen,which realizes the rapid regulation of electronic properties while maintaining the geometric configuration of the metal cluster.This rule was first demonstrated in the bare clusters without ligands,and then confirmed in the experimentally synthesized clusters.Considering that the solvent has a certain ability to stabilize electrons,we use the explicit model of water solvent with the highest polarity to carry out static and dynamic calculations in order to prove that the existence of the solvent improves the ability of clusters to gain electrons,rather than the solvent stabilizes extra electrons.The results show that the extra electrons are localized on the clusters in all situations,which indicates that the solvent is an important external field for improving the ability of clusters to obtain electrons.It proposed a noninvasive methodology different from the conventional methods of superatoms based on electron-counting rules and also provides a convenient way to design superhalogens.(2)The solvent environment is indispensable in the synthesis of liquid phase clusters,which is conducive to the stability of clusters,however,our understanding of the mechanism by which solvents affect the structure and electronic properties of different metal clusters is not comprehensive.Herein,Taking the Au13 cluster as typical representative,eight doping elements were selected to explore the effects of aqueous solvents on their geometric structure,electronic properties and oxygen adsorption and activation.The results show that the aqueous solvent can change the electronic properties of the doped M@Au12 clusters without breaking their geometric structure.Interestingly,we used the implicit solvent model to prove that the presence of water has a strong promoting effect on the adsorption of O2 molecules on clusters,and the participation of explicit water molecule makes it easy for hydrogenation reaction of O2 molecules with very low energy barrier.This study reveals the property effect of solvents on different doped gold clusters and their specific role in O2 activation,and provides a new way to understand the interaction between solvent and metal clusters. |
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