Spin filtering in self-assembled bowl-shaped aromatics

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Molecular Spintronics

Background:

• Bowl-shaped aromatic molecules possess chirality, enabling the formation of homochiral self-assembled structures.
• Chirality-induced spin selectivity (CISS) is a phenomenon where chiral materials can selectively transmit electrons based on their spin.
• The application of chiral self-assembled materials in molecular spintronics remains underexplored.

Purpose of the Study:

• To demonstrate the spin-filtering capabilities of columnar arrays formed by chiral subphthalocyanine (SubPc) molecules.
• To investigate how molecular engineering of SubPcs influences their self-assembly and spin-filtering performance.
• To explore the potential of these materials in the field of molecular spintronics.

Main Methods:

• Synthesis of enantiopure subphthalocyanine (SubPc) derivatives with varying peripheral groups.
• Characterization of self-assembled structures (fibers and nanorings) using techniques like atomic force microscopy.
• Measurement of spin polarization using magnetic-conductive atomic force microscopy (mc-AFM).

Main Results:

• Columnar arrays of chiral SubPcs were successfully formed, exhibiting different morphologies (fibers and nanorings) based on molecular design.
• These supramolecular architectures demonstrated effective spin filtering via the CISS effect.
• Observed spin polarization values ranged from 35% to 45%, indicating significant spin selectivity.

Conclusions:

• Chiral SubPc-based columnar assemblies can function as efficient spin filters.
• The self-assembled structure and intermolecular interactions play a crucial role in the observed spin-filtering properties.
• These findings open new avenues for utilizing chiral π-conjugated materials in molecular spintronics.