Unique Dynamic Electron‐Spin Polarization and Spin Dynamics in the Photoexcited Quartet High‐Spin State of an Acceptor–Donor–Radical Triad

Excited‐State Dynamics of Non‐Luminescent and Luminescent π‐Radicals

“…This unusual DEP pattern could be rationalized as a selective population (polarization) within high‐field spin sublevels . Later, similar DEP patterns were also observed for other acceptor–bridge–chromophores linked to π‐radical systems as well as a chromophore linked to an σ‐bonded radical . Such unusual DEP patterns polarized in the high‐field spin sublevels ( aee / aae ) have been previously observed only in the case of systems in which a radical pair was formed and underwent RP‐ISC followed by charge recombination to the local triplet state in either a mutated photosynthetic reaction center or its model systems .…”

“…In the case of bodipy-bridge-chromophore molecules with an appended p-radicala si llustrated in Figure 7a (bodipy:f luorophore boron dipyrromethene), our group reported the first observation of photoexcited quartet high-spin states with an unusualD EP pattern (aee/aae pattern; a/e:a bsorption/emission of the microwave), as shown in Figure 8a.T his unusual DEP pattern couldb er ationalized as as elective population (polarization)w ithin high-field spin sublevels. [19][20] Later,s imilar DEP patterns were also observed for othera cceptor-bridgechromophores linked to p-radical systems [103] as well as ac hromophore linked to an s-bonded radical. [27] Such unusual DEP patterns polarized in the high-field spin sublevels( aee/aae) have been previously observed only in the case of systems in which ar adical pair was formed andu nderwent RP-ISC followed by charger ecombination to the local triplet state in either am utated photosynthetic reactionc enter [53] or its model systems.…”

Compactly Fused o‐Quinone‐Extended Tetrathiafulvalene‐o‐Quinone Triad – a Redox‐Amphoteric Ligand

“…These compounds are regarded as building blocks for materials with nonlinear optical activity and rectifying properties. They have potential applications in quantum computing,1–5 molecular spintronics,6–8 high‐density information storage, and magnetic materials 9…”

Design, synthesis, magnetic properties of a π-radical ligand with photo-excited high-spin state and its Fe(ii) complex. The first stage of a new strategy for LIESST materials

“…16 We have studied the transient photo-induced spin alignment in the photo-excited state using purely organic π-conjugated spin systems which are constructed from an anthracene and stable radicals. [17][18][19][20][21][22][23][24] These are ideal model systems to study the spin alignment on photo-excited states, because they have the following advantages for materials science: (1) A strongly exchangecoupled spin alignment [17][18][19][20][21][22][23][24] is achieved compared to other triplet-radical exchange coupled systems (σ-bonded systems [25][26][27] and coordination complexes [28][29][30][31][32] ); (2) The desired spin state can be designed well by taking the topology of the π-electron network (π-topology) into account; [17][18][19][20][21][22] (3) An enhanced intersystem crossing owing to the spin-orbit coupling via π-conjugation to the radical spin is available [17][18][19][20][21][22] to open a new pathway. These π-radicals with high-spin photo-excited states are interesting because of fast photo-switching of the spin state 1 and magnetic interactions and are also the prototypes of photomagnetic molecular devices.…”

“…These π-radicals with high-spin photo-excited states are interesting because of fast photo-switching of the spin state 1 and magnetic interactions and are also the prototypes of photomagnetic molecular devices. 33 Recently, both experimentally 23,24 and theoretically, 34,35 we have investigated the high-spin states of functionalized π-radicals with unique dynamic electron polarization, which are generated through quantum mixed photoexcited states. In these systems, the unique dynamic electron polarization is generated by a dynamic process such as energy transfer, charge-separation and/or population transfers from the quantum-mixed state.…”