TY - JOUR

T1 - Revealing the Impact of g-Tensor Anisotropy on the Charge Recombination in Donor-Acceptor Dyads Under High Magnetic Fields

AU - Mentzel, Paul

AU - Gerhards, Luca

AU - Koppenhöfer, Denise

AU - Schmiedel, Alexander

AU - Holzapfel, Marco

AU - Lukzen, Nikita N.

AU - Solov’yov, Ilia A.

AU - Steiner, Ulrich E.

AU - Lambert, Christoph

N1 - We thank Prof. Martin Kaupp and Dr. Artur Wodyn\u0301ski from FU Berlin for the calculation of the TAA radical cation g-tensor. We also thank the Deutsche Forschungsgemeinschaft for supporting the experimental work in Wu\u0308rzburg (La991/20-1 and INST 93/1014-1 FUGG). The authors would also like to thank the Volkswagen Foundation (Lichtenberg professorship awarded to I.A.S.), the Deutsche Forschungsgemeinschaft (GRK1885 Molecular Basis of Sensory Biology; SFB 1372 Magnetoreception and Navigation in Vertebrates, no. 395940726 to I.A.S.; and TRR386-HYP*MOL, no. 514664767 to I. A. S. and L. G.), and the Ministry of Science and Culture of Lower Saxony Simulations Meet Experiments on the Nanoscale: Opening up the Quantum World to Artificial Intelligence (SMART) and Dynamik auf der Nanoskala: Von koha\u0308renten Elementarprozessen zur Funktionalita\u0308t (DyNano). N.N.L. thanks the Ministry of Science and Education of the Russian Federation for financial support.

PY - 2025/6/18

Y1 - 2025/6/18

N2 - Four new donor-acceptor dyads, featuring triarylamine donors and perylene diimide acceptors, were synthesized to investigate the influence of the g-tensor on the magnetic field-dependent spin dynamics of the resulting radical pairs. These pairs are characterized by the exchange interaction 2J being larger than the effective isotropic hyperfine coupling aeff. To control the isotropic g-factor and g-tensor anisotropy of the radical anion generated via photoinduced electron transfer, the perylene diimides were functionalized with phenyl chalcogen ethers. In dyads containing oxygen, sulfur, and selenium ether substituents, not only was the characteristic 2J-resonance observed but also a pronounced high-field effect in the charge recombination kinetics, extending up to B = 10 T. Quantum dynamics simulations based on the stochastic Liouville equation revealed that this effect is primarily driven by g-tensor anisotropy-induced relaxation, which increases along the chalcogen ether series. Additionally, we derived an exact analytical solution describing the impact of g-factor differences and g-tensor anisotropy on spin relaxation in the high-field limit. These findings highlight the critical role of g-tensor-induced relaxation in radical pairs at high magnetic fields, offering new insights for the molecular design of materials with potential applications in quantum information science, where incoherent relaxation processes should be avoided.

AB - Four new donor-acceptor dyads, featuring triarylamine donors and perylene diimide acceptors, were synthesized to investigate the influence of the g-tensor on the magnetic field-dependent spin dynamics of the resulting radical pairs. These pairs are characterized by the exchange interaction 2J being larger than the effective isotropic hyperfine coupling aeff. To control the isotropic g-factor and g-tensor anisotropy of the radical anion generated via photoinduced electron transfer, the perylene diimides were functionalized with phenyl chalcogen ethers. In dyads containing oxygen, sulfur, and selenium ether substituents, not only was the characteristic 2J-resonance observed but also a pronounced high-field effect in the charge recombination kinetics, extending up to B = 10 T. Quantum dynamics simulations based on the stochastic Liouville equation revealed that this effect is primarily driven by g-tensor anisotropy-induced relaxation, which increases along the chalcogen ether series. Additionally, we derived an exact analytical solution describing the impact of g-factor differences and g-tensor anisotropy on spin relaxation in the high-field limit. These findings highlight the critical role of g-tensor-induced relaxation in radical pairs at high magnetic fields, offering new insights for the molecular design of materials with potential applications in quantum information science, where incoherent relaxation processes should be avoided.

UR - https://www.mendeley.com/catalogue/b22a59f8-5a66-32f6-81b4-d273e1d466a0/

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-105008400514&origin=inward&txGid=5de868dfa4b874846c742597ecc9beb8

U2 - 10.1021/jacs.5c06173

DO - 10.1021/jacs.5c06173

M3 - Article

C2 - 40532090

VL - 147

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

SN - 0002-7863

IS - 26

ER -