Enantiopurity-Controlled Magnetism in a Two-Dimensional Organic-Inorganic Material

TL;DR

This study demonstrates that enantiomeric excess (ee) in 2D chiral organic-inorganic materials controls their magnetic properties, revealing new tuning strategies for magnetic behavior in hybrid materials.

Contribution

It introduces a method to control magnetism in 2D hybrid materials through enantiomeric excess, highlighting effects beyond absolute chirality.

Findings

Magnetism is determined by intercalant ee, not absolute chirality.

Low-ee materials exhibit thermally activated dynamic magnetism.

Local Mn vacancy ordering explains ee-dependent magnetic behaviors.

Abstract

Extended solids that combine unpaired electron spin and structural chirality can host unconventional magnetic behaviors with potential for electronic technologies. A versatile strategy for creating chiral solids is incorporation of chiral organic molecules into inorganic crystals. However, such hybrid organic-inorganic materials have so far been examined through the lens of absolute chirality, leaving enantiomeric excess (ee) underexplored as a tuning parameter. Here, we report two-dimensional (2D) intercalation compounds with controllable ee produced by cation exchange of MnPS$_3$ with chiral organic molecules. We show that these materials' magnetism is determined by intercalant ee rather than absolute chirality. Moreover, low-ee materials display thermally activated dynamic magnetism absent from enantiopure analogs. These ee-dependent magnetic behaviors are explained by local ordering of Mn vacancies, directed by correlated vacancy-intercalant electrostatics and confined molecular packing. Together, these results demonstrate a distinctive tuning strategy for molecule-material hybrids and establish design principles for 2D chiral and magnetically dynamic materials.