Sol–Gel-Derived 2D Nanostructures of Aluminum Hydroxide Acetate: Toward the Understanding of Nanostructure Formation

Two-dimensional (2D) metal oxide nanostructures have generated a great deal of attention in material science for their prospective wide-ranging applications; therefore, a scalable and economical method for producing these structures is an asset. In this research, a simple procedure for the preparation of 2D aluminum hydroxide acetate macromolecules ([Al­(OH)­(OAc)₂]_m) has been developed via a nonaqueous sol–gel route at a mild reaction temperature and ambient pressure. To gain a greater understanding of the mechanism for how the self-assembly of these 2D structures occurs, a combination of in situ Fourier transform infrared (FTIR) measurements and density functional theory (DFT) calculations were utilized. It was found that the bridging OH^–1 and coordination modes of the organic ligands guide the assembly of the planar nanostructures. The theoretical calculation results show that the structures of the [Al­(OH)­(OAc)₂]₈ oligomer can be either a linear or a planar structure, and the latter is more thermodynamically favorable than its linear counterpart. The simple synthesis method described herein could possibly open a new avenue for designing 2D nanostructures via ligand-directed anisotropic condensation reactions.