Hypermolecular Reaction-Based Precise Twist Angle Engineering in Molecular Moiré Superlattices Exhibiting Chirality Induced Spin Selectivity

Molecular electronics has significantly influenced the fields of molecular intelligence and quantum devices that include spintronics. In this regard, many non-magnetic chiral molecular systems are being studied for their application as spin filter, which is an important aspect of spintronics. Herein, we firstly define hypermolecule as assembly of molecules where two-dimensional crystalline assemblies are stacked twisted in the third dimension. An example of such assemblies is molecular moiré superlattices. We further report spin-selective electron transport in zinc-complexed molecular moiré superlattices of tryptophan (trp) having precisely controlled twist angles. The complexation reaction between the as-synthesized molecular moiré superlattices of trp and Zn2+ ions led to the twisted stacking of the nanolattices at precise angles. The molecular moiré superlattices were formed from the hypermolecular interactions between two nanosheets of the trp while the addition of Zn2+ ions led to their transition into other hypermolecular structures through covalent bonding. The resulting moiré superlattices were chiral in nature and displayed high spin polarizability that was dependent on the externally applied magnetic field strength.