Modulating Spontaneous Symmetry Breaking and Spin‐Dependent Transport in Supramolecular Assemblies of Achiral Porphyrins

Spin-selective electron transport, mediated by the chiral-induced spin selectivity (CISS) effect, has traditionally been associated with systems that either possess inherently chiral molecular frameworks or incorporate chiral species. In this study, we explore the occurrence of spin-dependent electron transport in mesoscale helical supramolecular assemblies formed entirely from an achiral porphyrin derivative. The supramolecular chirality in these assemblies is induced by a macroscopic chiral factor, specifically through vortex motion, resulting in distinct spin selectivity. Additionally, the generation of spin-polarized currents further substantiates the role of the CISS mechanism in directing electron spin, even in the absence of traditional chiral centres. To deepen our understanding of the interplay between supramolecular helicity and spin transport, we performed comparative studies by introducing chiral species into the system. This allowed us to evaluate the extent to which extrinsic chirality influences or enhances spin-selective behavior in achiral porphyrin assemblies. To further corroborate the spin-dependent process, we developed a prototype device with a spin-valve configuration. Notably, the results obtained from this device align well with the findings from all spin-dependent measurements. Overall, the results reveal nuanced insights into how chirality at different hierarchical levels can affect spin polarization, offering insightful implications for the design of self-assembled organic spintronic materials.