Enhanced coherence by coupling spins through a delocalized π-system: Vanadyl porphyrin dimers

Journal article

Vanadium(IV) magnetic centers are prime candidates for molecular quantum units. One long-standing question is how to obtain a scaffold that connects multiple centers and allows two communication modalities: magnetic and electronic. We have synthesized and studied a selection of vanadyl porphyrin dimers as models of the most synthetically accessible linear porphyrin arrays. We show that a strongly π-conjugated backbone places the magnetic system in an intermediate regime dominated by exchange coupling (J) and protects the quantum coherence against electron pair flip-flop processes at low temperatures (<10 K). This result is a fundamental step toward the design of molecular materials for single-molecule devices controlled by microwaves with electrical readout.

Authors: Pozo, I; Huang, Z; Alexandropoulos, DI; Slota, M; Tkach, I

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Cell Press
• Journal: Chem
• Volume: 10
• Issue: 1
• Pages: 299-316
• Publication date: 2024-10-11
• Acceptance date: 2023-09-18
• DOI: 10.1016/j.chempr.2023.09.013
• EISSN: 2451-9294
• ISSN: 1925-6981
• Language: English
• Keywords: molecular electronics; pi-conjugation; electron pair flip-flop; quantum coherence; electron paramagnetic resonance; magnetism; vanadyl porphyrins; spin; exchange coupling