TY - JOUR

T1 - Control of electronic and exchange coupling by bridge substituents in donor acceptor triads with triptycene bridges

AU - Lambert, Christoph

AU - Roger, Chantal

AU - Schmiedel, Alexander

AU - Holzapfel, Marco

AU - Lukzen, Nikita

AU - Steiner, Ulrich E.

N1 - We acknowledge the funding from the Deutsche Forschungsgemeinschaft (La/991 20-1). N. L. is grateful to the Ministry of Science and Higher Education of the Russian Federation (project #AAAA-A21-121012290043-3).

PY - 2024/9/11

Y1 - 2024/9/11

N2 - A series of triads, consisting of a triarylamine electron donor and a perylene diimide electron acceptor which were attached to two different wings of a triptycene bridging unit, was investigated concerning the dynamics of photoinduced charge separation and charge recombination processes with a particular focus on the involved spin-chemical aspects. Attaching electron-donating or electron-withdrawing substituents to the third wing of the triptycene bridge allowed tuning the electron transfer processes. These processes were investigated via fs-transient absorption spectroscopy and ns-transient absorption spectroscopy in an external magnetic field. The resulting magnetic field-dependent decay dynamics were analysed and modelled using the stochastic Liouville equation which yielded rate constants for the charge recombination and the exchange energy. In combination with a diabatic rate theory and Anderson's perturbative treatment of the exchange energy, these data gave a complete set of rate constants for charge separation and charge recombination from which the diverse electronic couplings between the involved states were derived. These couplings depend linearly on the inverse energy of virtual triptycene bridge states which allows tuning the electron transfer dynamics by modifying the triptycene bridge.

AB - A series of triads, consisting of a triarylamine electron donor and a perylene diimide electron acceptor which were attached to two different wings of a triptycene bridging unit, was investigated concerning the dynamics of photoinduced charge separation and charge recombination processes with a particular focus on the involved spin-chemical aspects. Attaching electron-donating or electron-withdrawing substituents to the third wing of the triptycene bridge allowed tuning the electron transfer processes. These processes were investigated via fs-transient absorption spectroscopy and ns-transient absorption spectroscopy in an external magnetic field. The resulting magnetic field-dependent decay dynamics were analysed and modelled using the stochastic Liouville equation which yielded rate constants for the charge recombination and the exchange energy. In combination with a diabatic rate theory and Anderson's perturbative treatment of the exchange energy, these data gave a complete set of rate constants for charge separation and charge recombination from which the diverse electronic couplings between the involved states were derived. These couplings depend linearly on the inverse energy of virtual triptycene bridge states which allows tuning the electron transfer dynamics by modifying the triptycene bridge.

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85205134790&origin=inward&txGid=9cb1968eb3415e0e88626562829e6c8b

UR - https://www.mendeley.com/catalogue/5051a4a3-a8d0-3d96-aac3-75c9537dbb00/

U2 - 10.1039/d4cp03148b

DO - 10.1039/d4cp03148b

M3 - Article

C2 - 39297794

VL - 26

SP - 24983

EP - 24994

JO - Physical Chemistry Chemical Physics

JF - Physical Chemistry Chemical Physics

SN - 1463-9076

IS - 38

ER -