Rational Design of Electric Field-Responsive Building Blocks for All-Organic 2D Magnetoelectric Materials
Year: 2025
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Development of technologically promising magnetoelectric materials, where magnetic properties can be controlled by electric fields (E-fields), has focused on inorganic systems. Here, we propose a strategy for modulating magnetic exchange coupling ( J ) in purely organic systems through experimentally realizable E-fields. Our approach leverages two established concepts: (i) E-field-induced twisting of dipolar organic linkers and (ii) control of J via conformational changes in organic diradicals. Using density functional theory calculations, we investigated the effects of applied E-fields on diradicals with two coplanar spin-carrying trioxotriangulene (TOT) radicals connected by dipolar aryl linkers. We find that E-fields induce significant conformational changes in the linkers (twisting) that alters π-conjugation and, in turn, the magnetic J coupling between TOT radicals. In-plane E-fields twist the linkers toward the plane of the radicals, enhancing π-conjugation and increasing AFM coupling. Out-of-plane E-fields induce more orthogonal linker conformations and decrease the coupling strength. The magnetoelectric response depends on a combination of steric hindrance, π-conjugation, and polarization. Significant and measurable cumulative changes in J of up to 3.9 meV could be achieved by using in-plane and out-of-plane E-fields of up to 0.5 V/Å. In some cases, applied E-fields can also induce switching between paramagnetism and antiferromagnetism. Calculations on a 2D covalent organic framework (COF) based on a network of TOT radicals and dipolar linkers confirm that this approach is also viable for extended systems. Such COFS could also display E-field induced ferroelectric responses. Overall, our proof-of-principle study highlights the interplay between molecular structure, E-fields, and magnetism and establishes an innovative and chemically rational framework for developing all-organic magnetoelectric materials.
DOI: 10.1021/jacs.5c02910
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Awards: G1105844351, G1175115578, G1184413409, G145641598, G1510469474, G1903514128, G2064873908, G2262748287, G2280140124, G2932050808, G3005324705, G300979063, G3393565032, G34346518, G3480869486, G3546882995, G382187973, G4181574914, G425668148, G4499571919, G4526231891, G464105488, G491712853, G5080475149, G5338730000, G5404395142, G5635532810, G624877701, G6731524417, G69051668, G7084143925, G734693063, G7434936867, G7805626310, G7818408929, G782112339, G7863371703, G8497050386, G919199058
OpenAlex ID: W4411373678