TY - JOUR

T1 - Simulation of electron and nuclear spin dynamics in many-spin charge-separated states

AU - Zhukov, Ivan

AU - Fishman, Natalya

AU - Lukzen, Nikita

AU - Klein, Johannes

AU - Steiner, Ulrich e.

AU - Lambert, Christoph

AU - Yurkovskaya, Alexandra

PY - 2025/2/5

Y1 - 2025/2/5

N2 - This study presents a numerical simulation approach to investigate singlet-triplet interconversion effects in organic materials with rigid molecular structures that facilitate the photogeneration of charge-separated (CS) states, such as zwitterions resulting from intramolecular electron transfer. Our approach enables the detailed modeling of electron and nuclear spin-dependent observables, including magnetic field-affected reaction yields (MARY) and chemically induced dynamic nuclear polarization (CIDNP). The equilibrium solution of the stochastic Liouville equation can be obtained with simple algebraic manipulation by noting the relationship between the Laplace transform of the density operator and the time-domain representation of the same operator. Experimental MARY and CIDNP data are modeled as functions of key external and internal system parameters, such as magnetic field strength, hyperfine interactions, and exchange couplings. This allows for exploring processes that are otherwise experimentally inaccessible, providing deeper insights into the spin dynamics of the photoinduced CS state. Understanding these interconversion processes is not only essential for the fundamental photochemistry studies but also for the rational design and development of novel organic materials for photovoltaics and photocatalysis. Our results demonstrate the significant impact of singlet-triplet interconversion on the overall efficiency of charge separation and recombination processes, highlighting the importance of spin dynamics in the design of next-generation organic photovoltaic materials.

AB - This study presents a numerical simulation approach to investigate singlet-triplet interconversion effects in organic materials with rigid molecular structures that facilitate the photogeneration of charge-separated (CS) states, such as zwitterions resulting from intramolecular electron transfer. Our approach enables the detailed modeling of electron and nuclear spin-dependent observables, including magnetic field-affected reaction yields (MARY) and chemically induced dynamic nuclear polarization (CIDNP). The equilibrium solution of the stochastic Liouville equation can be obtained with simple algebraic manipulation by noting the relationship between the Laplace transform of the density operator and the time-domain representation of the same operator. Experimental MARY and CIDNP data are modeled as functions of key external and internal system parameters, such as magnetic field strength, hyperfine interactions, and exchange couplings. This allows for exploring processes that are otherwise experimentally inaccessible, providing deeper insights into the spin dynamics of the photoinduced CS state. Understanding these interconversion processes is not only essential for the fundamental photochemistry studies but also for the rational design and development of novel organic materials for photovoltaics and photocatalysis. Our results demonstrate the significant impact of singlet-triplet interconversion on the overall efficiency of charge separation and recombination processes, highlighting the importance of spin dynamics in the design of next-generation organic photovoltaic materials.

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85217283336&origin=inward&txGid=44b5443b5b7aa923fae9d7d0f7544f7f

U2 - 10.1063/5.0244106

DO - 10.1063/5.0244106

M3 - Article

C2 - 39907133

VL - 162

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 5

M1 - 054116

ER -