Chemically Reversible Translational Moiré Superlattice Formations in the 2D Films of Zinc-Phthalate Complex

Two-dimensional (2D) moiré materials formed due to angular or translational mismatch between the consecutive lattices are emerging as extraordinary quantum materials, owing to their intrinsic physical properties that are different from ordinary 2D crystals. The control over precision in moiré periodicity is a current challenge for the evolving field. While physical methods offer great precision in positioning atomic 2D crystals such as graphene and hexagonal boron nitride, chemical methods of generating such structures in the liquid medium – especially involving molecules – need to be developed. Herein, we report the reaction mediated synthesis of translational moiré superlattices of zinc phthalate complexes in the aqueous medium with considerably precise moiré periodicity. Collective translation of the covalent framework of the zinc phthalate complex, and additional zinc ions stabilized between the inter-layer aromatic rings through metal-pi interaction led to the moiré superlattice formations. Further, facile interaction of the pi-bonded zinc ions with an externally added chelating ligand 8-hydroxy-5-sulfonic acid, resulted in the disappearance of the moiré patterns. Again, the addition of zinc ions to the reaction mixture followed by storing the reaction mixture for 24 h led to the regeneration of the moiré patterns indicating the reversibility of the process.