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Updated: Sep 17, 2025

Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser
Published on: June 28, 2018
Spin-Correlated Radical Pairs as Magnetic Switches for Controlling Emissive Triplet States via Triplet-Triplet Energy
Neo Lin1, Madalyn J Zagajowski2, Tatiana V Esipova2
1Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States.
Abstract:
Magnetic fields offer a powerful means to control molecular emission, enabling quantum sensing and spin-level control of chemical reactions. Here, we demonstrate a strategy to magnetically control red to near-infrared phosphorescence via triplet-triplet energy transfer (TTET) from donor-chiral bridge-acceptor (D-χ-A) molecules that generate spin-correlated radical pairs (SCRPs) upon photoexcitation. These SCRPs yield non-emissive triplet excited states whose formation is sensitive to magnetic fields. By transferring this energy to emissive Pt- and Pd-based π-extended porphyrins, we enable magnetic control over phosphorescence that would otherwise be unresponsive to weak magnetic fields (<1 T). This approach establishes a platform for quantifying magnetic field effects on silent triplet states while extending magnetically responsive emission into the near-infrared. Coupling SCRP-based molecular magnetic switches to long-wavelength emissive acceptors offers a new way for probing and modulating spin-dependent processes and triplet-state populations in molecular systems.
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