A Theoretical Exploration Of The Interaction Of Small Molecules With The (ZnS)_n Clusters

The nature of the interaction of small molecules with (ZnS)_n clusters with n=9-26, 50, 60 have been studied by density functional theory. All density functional theory (DFT) calculations were performed with the GGA-BLYP function using the Dmol³ code. All-electron double numerical plus polarization (DNP) basis sets, which are of the highest quality among all the available basis sets within the Dmol³ code, were employed for all atoms. Geometry optimizations were performed with the BFGS algorithm at the GGA-BLYP/DNP level of theory and the frequency calculations have been performed at the same level of theory and it confirmed that the structures are at their energy minima. The structure, the binding energy, hirshfeld charge, MOs and Mulliken population analysis were investigated.Main results and conclusions were summarized as follow:1. Interaction of (ZnS)_n (n=9-26, 32, 44, 50 and 60) clusters with neutral molecule(ZnS)_n clusters have been studied and compared the changes in their structures and properties due to the presence of water. The dominant reaction sites between cluster and water molecule are Zn ions. The H atoms toward to the S atoms. The charges transfer was also observed as guest molecule to S atom in cluster. The calculated results illustrate the geometry changes in ZnS while the guest molecule interacts with cluster. All of the (ZnS)_n (n=9-26,32,44,50 and 60) clusters have the same tendency interact with H₂O molecule. Note that this study provides the atomic-scale mechanisms to reveal the changes in the surface environment of cause the structural changes.2. Interaction of (ZnS)_n clusters with Lewis baseThe dominant reaction sites between cluster and ammonia molecule are Zn ions. Three H atoms toward to the S atoms. The charges transfer was also observed as guest molecule to S atom in cluster. The calculated results illustrate the geometry changes in ZnS while the guest molecule interacts with cluster. All of the (ZnS)_n (n=9-26,32,44,50 and 60) clusters have the same tendency interact with NH3 molecule Density functional theory (DFT) methods have been used to study the interaction of (ZnS)_n (n=12,26 and 60) clusters with water, ammonia, sodium hydroxide, lithium hydroxide, sodium amide and lithium amide molecules. (ZnS)_n (n=12, 26 and 60) clusters have the same tendency in interacting with these molecules. The study of the correlation between the binding energy, and bond lengths revealed that the change of structure depends on the choice of molecules with (ZnS)_n clusters. Control of structures of (ZnS)_n clusters was achieved by chemical modification. In these molecules, the binding energy increased with the increase of alkalescency of small molecules.The advantage of using cluster model to describe the interactions between guest molecule and ZnS nanomaterials will provide helpful information to understand the experimental phenomenon.