Singlet fission can generate an exchange-coupled quintet triplet pair state

Abstract A series of ferrocene(Fc)‐bridged pentacene(Pc)‐dimers [Fc−Ph(2, n )−(Pc) 2 : =number phenylene spacers] were synthesized to examine the tortional motion effect Fc‐terminated linkers on strongly coupled quintet multiexciton ( 5 TT) formation through intramolecular singlet fission (ISF). Fc−Ph(2,4)−(Pc) has a relatively small electronic coupling and large conformational flexibility according spectroscopic theoretical analyses. exhibits high‐yield TT together with quantitative 1...

We developed organocatalyst systems to promote the cleavage of stable C–H bonds, such as formyl, α-hydroxy, and benzylic through a hydrogen atom transfer (HAT) process without use exogenous photosensitizers. An electronically tuned thiophosphoric acid, 7,7'-OMe-TPA, was assembled with substrate or co-catalyst N-heteroaromatics bonding π–π interactions form electron donor–acceptor (EDA) complexes. Photoirradiation EDA complex induced stepwise, sequential single-electron (SET) processes...

Importance of vibronic effects has been highlighted for the singlet-fission (SF) that converts one high-energy singlet exciton into doubled triplet excitons, as strongly coupled multiexcitons. However, molecular mechanisms spin conversion processes and ultimate decouplings in multiexcitons are poorly understood. We have analyzed geometries exchange couplings (singlet–quintet energy gaps: 6J) photoinduced pentacene dimers bridged by a phenylene at ortho meta positions [denoted o-(Pc)2...

Singlet fission (SF) is a promising approach in quantum information science because it can generate spin-entangled quintet triplet pairs by photoexcitation independent of temperature. However, still challenging to rationally achieve coherence at room temperature, which requires precise control the orientation and dynamics pairs. Here we show that multiexcitons be achieved temperature arranging two pentacene chromophores parallel close proximity within macrocycle. By making dynamic covalent...

Light-driven spin hyperpolarization of organic molecules is a crucial technique for spin-based applications such as quantum information science (QIS) and dynamic nuclear polarization (DNP). Synthetic chemistry provides the design spins with atomic precision enables scale-up individual to hierarchical structures. The high designability extended pore structure metal–organic frameworks (MOFs) can control interactions between guest molecules. However, effective polarizing radical electron by...

Light-energy conversion processes causing alternations in spin multiplicity are attracting attention, but the development of quantum sensing technology applicable to fluid environment such as inside cells has been unexploited. How achieve efficient energy with controlling coherence a noisy condensed system is challenging. In this study, we investigate effect molecular motion on electron polarization control information three-spin qubits by using steric effects organic molecules at room...

Despite significant recent advances in the development of organic photosensitizers (PSs), designing a PS with both long-wavelength absorption and high reducing ability remains challenging. In this study, we introduce carbazol-3-olates...

We present a novel design concept of molecular dimers for quantitative individual triplet yield (ΦΤ) through intramolecular singlet fission. synthesized series tetracene (Tc) bridged by different phenylene-based linkers, focusing on the conformational flexibility in addition to electronic coupling. In transient absorption measurements, 4,4′-biphenyl-bridged Tc dimer with weaker coupling and larger exhibited ΦΤ: 196 ± 12% at high excitation energy. Moreover, decoupled spins associated change...

Abstract We newly synthesized a series of homo‐ and hetero‐tetracene (Tc) oligomers to propose molecular design strategy for the efficient exciton transport in linear by promoting correlated triplet pair (TT) dissociation controlling sequential trapping process individual doubled excitons (T+T) intramolecular singlet fission. First, entropic gain effects on number Tc units are examined comparing Tc‐homo‐oligomers [(Tc) n : =2, 4, 6]. Then, comparison Tc‐hetero‐oligomer [TcF 3 ‐(Tc) 4 ‐TcF ]...

We present a theoretical model of analysis the time-resolved electron paramagnetic resonance (TREPR) spectrum charge-separated (CS) state generated by photoinduced transfer (ET) reaction via locally excited triplet in an donor-acceptor (D-A) system with fixed molecular orientation. show, stochastic-Liouville equation, that chemically induced dynamic polarization (CIDEP) mechanism is explained lack quantum coherence terms primary spin state, resulting net emissive or absorptive (ESP) which...

A series of DNA hairpins (AqGn) possessing a tethered anthraquinone (Aq) end-capping group were synthesized in which the distance between Aq and guanine-cytosine (G-C) base pair was systematically varied by changing number (n - 1) adenine-thymine (A-T) pairs them. The photophysics photochemistry these investigated using nanosecond transient absorption time-resolved electron paramagnetic resonance (TREPR) spectroscopy. Upon photoexcitation, (1*)Aq undergoes rapid intersystem crossing to yield...

Hexacene (Hc) is highly promising for singlet fission (SF). However, the number of SFs in Hc extremely limited. As far as dimers solution are concerned, there no report on observation dissociation process from a correlated triplet pair (TT) to an individual one. The emphasis this study first quantitative TT generation together with orientation-dependent photophysical discussions using para- and meta-phenyl-bridged dimers. Moreover, activation enthalpies smaller than those pentacene (Pc)...

Abstract Photostimulated luminescence allows energy or data to be stored and released using electromagnetic waves as both the input output, has attracted considerable interest in fields of biomedical information technologies. However, this phenomenon is mostly limited solid inorganic materials. Here, we report photostimulated from purely organic blend films, composed electron donor, acceptor, trap/emitter molecules. Charges films are accumulated radical ions by ultraviolet light irradiation...

To elucidate how the protein–ligand docking structure affects electronic interactions in electron-transfer process, we have analyzed time-resolved electron paramagnetic resonance spectra of photoinduced charge-separated (CS) states generated by light excitation 9,10-anthraquinone-1-sulfonate (AQ1S–) bound to human serum albumin at a hydrophobic drug-binding region. The been explained terms triplet–triplet spin polarization transfer model determine both geometries and exchange couplings CS...

The use of renewable solar energy for the photochemical CO2 reduction reaction (CO2RR) has garnered significant interest owing to its dual benefits: reducing greenhouse effect and producing high-energy alternatives fossil fuels. Transition metals play a crucial role in catalyzing CO2RR; however, their scarcity high cost pose challenges achieving sustainable chemistry. In this study, we developed metal-free CO2RR catalytic system using triazolium, small structurally simple compound, as key...

In the biological magnetic compass, blue-light photoreceptor protein of cryptochrome is thought to conduct sensing Earth's field by photoinduced sequential long-range charge-separation (CS) through a cascade tryptophan residues, WA(H), WB(H) and WC(H). Mechanism generating weak-field sensitive radical pair (RP) poorly understood because geometries, electronic couplings their modulations molecular motion have not been investigated in secondary CS states generated prior terminal RP states....

Singlet fission (SF) can generate an exchange-coupled quintet triplet pair state 5TT, which could lead to the realization of quantum computing and sensing using entangled multiple qubits even at room temperature. However, observation coherence 5TT has been limited cryogenic temperatures, fundamental question is what kind material design will enable its room-temperature coherence. Here we show that SF-derived in a chromophore-integrated metal-organic framework (MOF) be over hundred...

To elucidate how local molecular conformations play a role on electronic couplings for the long-range photoinduced charge-separated (CS) states in protein systems, we have analyzed time-resolved electron paramagnetic resonance (TREPR) spectra by polarized laser irradiations of 9,10-anthraquinone-1-sulfonate (AQ1S–) bound to human serum albumin (HSA). Analyses magnetophotoselection effects EPR and docking simulation clarified geometry coupling CS AQ1S•2–-tryptophan214 radical cation (W214•+)...

2,2,5,5-Tetramethyl-3,6-diphenyl-2,5-dihydropentalene-1,4-dione (PD-H) and its dimethoxy (PD-OCH3) bis(trifluoromethyl) derivatives (PD-CF3) were developed as a new class of compounds possessing wide excited singlet-triplet energy gap. The PD would also have high level the triplet-excited state (ET) due to planarity fused-diene subunit. results photophysical studies revealed that singlet-excited (ES) ET PD-H are 2.88 1.43 eV, respectively. These values indicate has relationship, ES > 2ET,...

Abstract A series of ferrocene(Fc)‐bridged pentacene(Pc)‐dimers [Fc−Ph(2, n )−(Pc) 2 : =number phenylene spacers] were synthesized to examine the tortional motion effect Fc‐terminated linkers on strongly coupled quintet multiexciton ( 5 TT) formation through intramolecular singlet fission (ISF). Fc−Ph(2,4)−(Pc) has a relatively small electronic coupling and large conformational flexibility according spectroscopic theoretical analyses. exhibits high‐yield TT together with quantitative 1...

Singlet fission (SF) is a promising approach in quantum information science because it can generate spin-entangled quintet triplet pairs by photoexcitation independent of temperature. However, still challenging to rationally achieve coherence at room temperature, which requires precise control the orientation and dynamics pairs. Here we show that multiexcitons be achieved temperature arranging two pentacene chromophores parallel close proximity within macrocycle. By making dynamic covalent...