Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

Very high photoluminescence intensity of a Eu(iii) complex is achieved using a host–guest system. The intensity is 400 times larger than that of the Eu(iii) complex itself.

DOI： 10.1039/D3SC01817B

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Singlet fission (SF), converting a singlet excited state into a spin-correlated triplet-pair state, is an effective way to generate a spin quintet state in organic materials. Although its application to photovoltaics as an exciton multiplier has been extensively studied, the use of its unique spin degree of freedom has been largely unexplored. Here, we demonstrate that the spin polarization of the quintet multiexcitons generated by SF improves the sensitivity of magnetic resonance of water molecules through dynamic nuclear polarization (DNP). We form supramolecular assemblies of a few pentacene chromophores and use SF-born quintet spins to achieve DNP of water-glycerol, the most basic biological matrix, as evidenced by the dependence of nuclear polarization enhancement on magnetic field and microwave power. Our demonstration opens a use of SF as a polarized spin generator in bio-quantum technology.

Repository Public URL： https://hdl.handle.net/2324/7234644

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/acs.jpcc.1c04283

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熱活性化遅延蛍光（TADF）の設計は、ESTを小さくするために遷移が関わる軌道の重なりを小さくしなければならないが、発光特性の観点からは重なりを大きくする必要があり本質的な矛盾が内在している。ドナー‐アクセプター型のTADF材料のDA二面角揺らぎを制御した分子に対する時間分解赤外分光と量子化学計算により励起状態での構造変化の比較検討を元に、二面角揺らぎがこの矛盾を解決する糸口になり得ると提案した。

DOI： 10.1063/5.0029608

Other Link： https://doi.org/10.1063/5.0029608

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DOI： 10.1021/acs.jpca.0c02224

Other Link： https://doi.org/10.1021/acs.jpca.0c02224

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DOI： 10.1063/1.5127993

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熱活性化遅延蛍光は高効率有機発光ダイオードを達成する新しい原理として注目を集めているが、微視的な原理はいまだに明らかになっていない。開発を促進するためにも、分子レベルでの発光メカニズムを解明することは急務である。本論文では、同様の構造を持つにもかかわらず異なる熱活性化遅延蛍光能を持つ分子群に注目し、本研究室で独自に開発してきた時間分解赤外分光を用いて励起状態の分子の立体構造変化を追跡した。結果として、励起状態で分子の立体構造変化が抑制されている場合に発光能が著しく高いことがわかった。この発見は熱活性遅延蛍光分子のデザイン指針の確立に大きく貢献するものである。

DOI： 10.1021/acs.jpclett.9b00810

Other Link： https://pubs.acs.org/doi/abs/10.1021/acs.jpclett.9b00810

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オプトエレクトロニクスで非常に重要な位置づけとなっている新規材料鉛ハライドペロブスカイトについて、その特異な電子物性を理解する鍵として強誘電材料としても側面を議論した論文。印加された電場に対して非常に大きく応答できる高誘電率といった性質から、注入されたキャリアが周囲に微視的な強誘電相転移を誘起する可能性について言及し、Ferroelectric polaronという全く新しい概念を提唱した。

DOI： 10.1038/s41563-018-0068-7

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DOI： 10.1126/sciadv.1701469

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DOI： 10.1038/NCHEM.2784

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DOI： 10.1126/sciadv.1701217

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DOI： 10.1126/science.aaf9570

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DOI： 10.1103/PhysRevB.91.195306

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DOI： 10.1039/d6cc00558f

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Journal of Materials Chemistry C  

This study explores the mechanochromic behavior of dinuclear aluminum-based triple-stranded helicates with various halogenated substituents. Mechanical grinding induces distinct color changes, with powder X-ray diffraction confirming phase transitions between crystalline and amorphous states. In the crystalline phase, the helicates adopt a more twisted conformation that limits π-conjugation, producing monomeric yellow emission. In contrast, in the amorphous phase, this twist relaxes and the π-conjugated system is extended, yielding orange emission. The original emission properties can be restored through solvent treatment, demonstrating the reversible nature of this mechanochromic behavior. These results demonstrate a mechanochromic mechanism governed by reversible torsion-angle changes and highlight aluminum-based helicates as promising responsive luminescent materials.

DOI： 10.1039/d5tc04488j

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Chemphotochem  

The successive photosubstitution reaction from cis-[Ru(bpy)<inf>2</inf>(MeCN)<inf>2</inf>]²⁺ to cis-[Ru(bpy)<inf>2</inf>(pz)(pzH)]⁺ was investigated under various conditions (bpy = 2,2′-bipyridine, pzH = pyrazole). Temperature-dependent studies revealed that distinct mechanistic features: the first step, conversion from cis-[Ru(bpy)<inf>2</inf>(MeCN)<inf>2</inf>]²⁺ to cis-[Ru(bpy)<inf>2</inf>(pzH)(MeCN)]²⁺, proceed in a temperature-independent manner, whereas the second step, yielding cis-[Ru(bpy)<inf>2</inf>(pz)(pzH)]⁺, is strongly temperature-dependent with an activation energy of 12.8 ± 1.4 kJ/mol. Transient absorption spectroscopy of the intermediate, cis-[Ru(bpy)<inf>2</inf>(pzH)(MeCN)]²⁺, determined an activation energy of 18.6 ± 0.3 kJ/mol for the transition from the ³MLCT to ³MC states, consistent with the activation energy observed for second photosubstitution reactions (MLCT: metal-to-ligand charge–transfer, MC: metal-centered). The first photosubstitution was unaffected by the nature of incoming imine ligands, indicating that the photodissociation of acetonitrile occurs rapidly. In contrast, the second photosubstitution step was influenced by the σ-donating ability of the pyrazole ligand and the basicity of the base, which facilitates deprotonation and promotes intramolecular hydrogen bonding between pyrazole ligands. The photosubstitution product, cis-[Ru(bpy)<inf>2</inf>(pz)(pzH)]⁺, exhibited ³MLCT-state lifetimes that were much shorter by nearly an order of magnitude compared to the intermediate, as determined from the transient absorption spectra.

DOI： 10.1002/cptc.202500392

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Journal of the American Chemical Society  

The synthesis and characterization of a fused rubrene derivative with two embedded seven-membered rings are described. Owing to the incorporation of heptagons, fused rubrene was obtained as two isolable conformers in the C<inf>2h</inf>-symmetric saddle and D<inf>2</inf>-symmetric twisted structures. The isomers were both highly curved, as judged from the mean plane deviation of 1.10 Å (saddle) and 1.15 Å (twist). Kinetic studies using NMR spectroscopy and DFT calculations revealed that the saddle isomer was 11.0 kJ·mol^–1 more stable at 25 °C than the twisted isomer. The isomers were kinetically stable under ambient conditions but interconverted at high temperatures with an isomerization barrier of 136.2 kJ·mol^–1 at 25 °C from the twist to the saddle isomer. Both isomers displayed narrower optical band gaps than the nonfused rubrene. The two isomers exhibited optical properties that depended on their different molecular curvatures, which are thoroughly addressed in this work. The fused structure also enhanced the photostability compared with that of rubrene. Transient absorption studies suggested fast (τ = 7.2 ps) singlet fission of the twisted isomer in a thin film upon photoirradiation. Single-crystal OFET measurements demonstrated that the hole mobility of the crystalline saddle isomer is comparable to that of representative PAHs employed as organic semiconductors.

DOI： 10.1021/jacs.5c22771

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

Two-dimensional electronic spectroscopy (2DES) has been widely employed to probe the dynamics of electronic excitations. However, conventional 2DES often encounters challenges in spectral assignment due to the intrinsic limitations of transient absorption detection. To overcome these issues, fluorescence-detected 2DES has been anticipated, and broadband excitation sources can enhance its performance. In this study, we have developed a two-dimensional fluorescence excitation (2DFLEX) spectroscopy by combining white-light excitation with Kerr-gate detection. This approach exploits the white light generated from a high-repetition-rate Yb-amplifier laser, providing both broad spectral coverage and excellent stability. Importantly, 2DFLEX exhibits intrinsic selectivity for stimulated emission, enabling the isolation of excited-state dynamics. This technique represents a significant advancement in fluorescence-detected 2DES and opens new opportunities for elucidating complex electronic processes. 2DFLEX is a spectroscopic technique that integrates excitation-spectrum measurements with time-resolved photoluminescence and has the potential to become a novel standard analytical method for photofunctional materials.

DOI： 10.1021/acs.jpclett.5c03373

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Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

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Aggregation‐induced emission luminogens (AIEgens) are typically large π‐conjugated molecules, but their low affinity and noninvasiveness toward analytes limit practical applications. To address this, smaller, more planar AIEgens are needed. Stilbene, though structurally suitable, lacks visible luminescence. Here, we report a minimally modified stilbene‐based AIEgen—4‐dipropylamino‐4’‐cyano‐bridged stilbene ( DpCBS[7] )—that exhibits fluorescence solvatochromism and efficient AIE across a broad polarity range in the visible region. DpCBS[7] exhibits low quantum yields ( Φ _fl = 0.01–0.04) in solvents from nonpolar n ‐hexane to polar dimethyl sulfoxide, with large Stokes shifts, viscosity‐sensitive luminescence, and highly efficient solid‐state luminescence ( Φ _fl = 0.70). To elucidate its dual solvatochromic and AIE behavior, femtosecond transient absorption spectroscopy was conducted. In solution, DpCBS[7] displays transient absorption with lifetimes of 21 ps (toluene) and 56 ps (acetonitrile) at 293 K, indicating ultrafast nonradiative decay leading to low Φ _fl . Arrhenius analysis over the temperature range of 263–313 K revealed activation energies (Δ E _a ) of 9.90 kJ/mol in toluene and 12.8 kJ/mol in acetonitrile for the S ₁ → S ₀ decay of DpCBS[7] . The Δ E _a values show no clear systematic dependence on solvent polarity. In contrast, pre‐exponential factor A remains consistently high regardless of solvent polarity, indicating that the striking photophysical response is governed primarily by the pre‐exponential factor rather than by modulation of the activation energy. These findings highlight the fundamental importance of tailoring the distribution function through structural modification as a robust strategy to control AIE characteristics.

DOI： 10.1002/agt2.70295

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/agt2.70295

Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

Luminescent organic radicals often exhibit a red-shifted, broad, and structureless emission band when assembled in a host matrix. This emission has been attributed to pairs of neighboring photoexcited and ground-state radicals forming an excimer. However, the electronic character of this “excimer-like” (EX) state has not been definitively clarified through experiments. Here we present an experimental characterization of this EX state using a spatially confined luminescent diradical as a model for radical dimers. Comprehensive spectroscopic investigations revealed that the EX state of the diradical is a zwitterionic (ZI) state with a closed-shell singlet electronic configuration generated by intramolecular symmetry-breaking radical-to-radical charge transfer. In combination with previous magnetoluminescence studies, we experimentally show that the formation of the ZI state is specific to the singlet spin state. Our results enable a detailed understanding of the photophysics and photochemistry of radical multichromophoric systems for future spin photonics applications.

DOI： 10.1021/jacs.5c17112

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Elongation of the triplet metal-to-ligand charge transfer excited state (MLCT) lifetimes in Fe(II) complexes is particularly important because of their 3d⁶ electronic configuration that is analogous to that of the well-studied photoactive Ru polypyridyl complexes. Toward extending ³MLCT state lifetimes, the use of strongly σ-donating NHC ligands is known to suppress unwanted deactivations through d-d states. Hexa-NHC coordination environments seem highly promising to provide strong ligand fields; however, Fe(II) hexa-NHC complexes are unstable in air and are oxidized to Fe(III) oxidation states under ambient conditions. In this study, we sought an air-stable Fe(II) hexa-NHC complex with a slightly weaker σ-donor from a triazole-based NHC ligand, and its photoexcited state dynamics were determined by femtosecond transient absorption spectroscopy. The obtained Fe(II) state is stable under ambient conditions (E(Fe^3+/2+) = 0.33 V vs Fc^+/0), and its photoexcited state characteristics are similar to those of reported electrochemically reduced Fe(II) hexa-NHC complexes. Our findings revealed that Fe(II) oxidation states can be stabilized while keeping a strong ligand field nature of NHCs. Although the ³MLCT lifetime remains short-lived (1.4 ps), air-stable Fe(II) hexa-NHC complexes are amenable to further exploration of the long-lived ³MLCT states in Fe(II) complexes.

DOI： 10.1021/acs.inorgchem.5c05069

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Chemistry A European Journal  

μ-Oxo dimers of octaaryl-substituted silicon porphyrazines (SiPzs) were synthesized for the first time. The steric congestion due to the peripheral aryl groups attenuated the rotation of the SiPz units around the Si–O–Si axis, resulting in the fixed D<inf>4</inf> symmetric conformations with the torsion angle of ∼23° at room temperature or lower, which were unambiguously elucidated by the single-crystal X-ray diffraction analysis and variable-temperature NMR studies. The interlayer molecular orbital interactions between the stacked SiPz units perturbed UV/vis absorption spectra and electrochemical properties of the dimers. In addition, the hetero-type dimer, bearing electron-donating and electron-withdrawing aryl-substituents on each SiPz unit, showed a large two-photon absorption cross-section based on the reverse saturable absorption mechanism mediated by the intramolecular charge transfer interactions.

DOI： 10.1002/chem.202502913

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Organic room-temperature phosphorescence (RTP) materials have garnered significant interest in various crucial applications. While RTP emissions typically exhibit a water-induced quenching propensity, the impact of genuine water accommodation into porous materials on RTP properties remains unclear and confusing due to the lack of structural evidence and ambiguous mechanism of water-regulated RTP properties. Herein, we demonstrate the manipulation of RTP properties through water-accommodation-induced structural dynamics in a flexible hydrogen-bonded organic framework (FHOF) system. Through water accommodation in voids, a reversible structural transformation between the closed- and open-pore phases occurs, integrated with a counterintuitive turn-on RTP feature. Comprehensive photophysical, structural, and theoretical analyses reveal that the water-promoted RTP behavior is correlated with the structural transition, which results from the water-induced effective regulations of both the intersystem crossing process and the triplet nonradiative decays. Furthermore, the water adsorption events can be converted into direct, naked-eye-visible feedback, demonstrating great potential in time-resolved information delivery and encoding applications. This work elucidates the role of water accommodation in the manipulation of RTP properties, which not only establishes the correlation between water-regulated triplet exciton behaviors and structural dynamics but also opens new opportunities for the development of future multifunctional and intelligent flexible porous materials.

DOI： 10.1021/jacs.5c15000

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Transient absorption spectroscopy of azulene dimers with various bridge structures revealed that the anti-Kasha emission of azulene is highly sensitive to electronic interactions between chromophores.

DOI： 10.1039/d5cp02571k

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Solvent-free molecular liquids exhibiting highly efficient room-temperature phosphorescence are reported.

DOI： 10.1039/d5sc03768a

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Language：English   Publisher：American Chemical Society (ACS)  

DOI： 10.26434/chemrxiv-2025-18fwh

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Boron nitride nanotubes (BNNTs) are used for the self-assembly of tetracene (Tc) molecules without chemical modification in their one-dimensional nanocavities. The Tc aggregated state can be changed depending on the encapsulated Tc amount that is controlled by the sublimation conditions of Tc molecules for the complexation (Tc@BNNTs). As a result, the photophysical processes, including singlet fission in the Tc assemblies, are varied, which enables the emission mode switching of the aggregation-based fluorescence and the excimer emission for Tc@BNNTs. Consequently, the host–guest complexation using BNNTs allows not only the fabrication and evaluation of optically functionalized molecular assemblies in the nanocavity but also the modulation of their photophysical processes, by which the emission colors of Tc@BNNTs are also tuned.

DOI： 10.1021/acs.jpclett.5c01618

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Molecular symmetry is a central design element in functional materials, yet its dynamic modulation in the excited state and its consequences for optoelectronic properties remain largely unexplored, particularly in main-group p-block element complexes. We address this knowledge gap by investigating unique Al(III) dinuclear triple-helical complexes that combine high symmetry with twisted π-conjugated systems and achieve exceptional optical properties of unusually large Stokes shifts and high photoluminescence quantum yields. Using transient absorption spectroscopy with a 10 fs pump pulse, we detected coherent vibrational oscillations overlapped with transient absorption/stimulated emission signals. Analysis of the dephasing times of oscillatory signals revealed photoexcitation-triggered Jahn–Teller distortions in these high-symmetry p-block complexes, evidenced by a specifically short dephasing time constant of 410 fs associated with intraligand twisting vibrations. Our findings demonstrate that excited-state symmetry breaking, strongly coupled with intraligand twisting vibrations, is crucial in determining the remarkable photofunctional properties of large Stokes shifts and high photoluminescence quantum yields. This work elucidates the fundamental mechanisms underlying the performance of these Al(III) complexes and provides a conceptual framework for designing next-generation photofunctional materials by harnessing dynamic symmetry changes.

DOI： 10.1021/jacs.5c06020

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Using picosecond photoluminescence spectroscopy, we found the emission mechanism common for the linearly-linked donor–acceptor-type thermally activated delayed fluorescence molecules, which is attributed to two conformers in the ground state.

DOI： 10.1039/d5cp01226k

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Nature Communications  

In recent years, thermally activated delayed fluorescence (TADF) has attracted intense attention owing to its straightforward application to high-efficiency organic light-emitting diodes. Further, to develop high-performance TADF materials, many researchers have designed novel molecules that have a small energy gap between the lowest excited singlet and triplet states (ΔEST), and detailed analysis suggests a significant contribution of higher-lying excited states for spin flipping processes. In this study, we demonstrate a peculiar thermal behaviour of emission decay of a donor–acceptor type TADF molecule, TMCz-BO, which seems like thermal deactivation of delayed fluorescence that can be explained without a negative ΔEST by comprehensive kinetic analysis across various temperatures and solvents. While the activation energy has previously been treated as being temperature-independent, we stress that it should be a dynamic parameter affected by changing the solvent-solute interaction with the environmental temperature, especially in the case of a small energy gap.

DOI： 10.1038/s41467-025-59910-z

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Organic lasers hold great promise for enabling a new class of future optoelectronics. Consequently, the development of new organic semiconductors as gain media has recently been the subject of significant interest. The molecular design principle based on Einstein coefficients has been validated for achieving high gain, with para‐phenylene‐vinylene scaffolds recognized as one of the most crucial frameworks. In this study, we develop a stilbene tetramer derivative, QSBCz, which has significantly increased conjugation compared to the highly efficient laser material, BSBCz, resulting in a remarkably high radiative decay rate and a large gain cross‐section. However, we find that the optical losses play a significant role in the light amplification of QSBCz. Indeed, a comprehensive understanding and suppression of detrimental optical loss pathways throughout the lasing process are essential, whereas the losses intrinsically associated with molecules have not been well considered. Although host–guest systems are helpful in preventing concentration quenching in aggregated states, this study reveals notable losses when using common host molecules such as 4,4′‐bis(9H‐carbazol‐9‐yl)biphenyl (CBP) and mCBP. In contrast, a BSBCz derivative is successfully employed as the host, leading to improved stimulated emission amplification. These findings indicate the importance of host–emitter interactions in lasing properties and highlight the necessity to optimize host materials for developing new laser dyes.

DOI： 10.1002/agt2.70030

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Development of near‐infrared (NIR)‐light‐driven photocatalytic hydrogen (H₂) production is indispensable for an efficient use of solar energy in a sustainable society. Herein, a strategy is reported for achieving higher quantum yields of NIR‐light‐driven photocatalytic H₂ production using salts of diprotonated dodecaphenylporphyrin (H₄DPP²⁺(X⁻)₂), showing large saddle distortion as organic photosensitizers and platinum nanoparticles as catalysts. When a perchlorate ion (ClO₄⁻) is employed as a counter ion (X⁻) of H₄DPP²⁺(X⁻)₂, the quantum yield of the photocatalytic H₂ production reaches to 36% by excitation at 750 nm, which is the highest value among those of NIR‐light‐driven H₂ production reported so far. Such a drastic enhancement of the quantum yield is achieved by selection of X⁻ as an appropriate counter anion of H₄DPP²⁺, judging from second‐order rate constants of photoinduced electron transfer (ET) from electron donors to ³(H₄DPP²⁺(X⁻)₂)* and the reorganization energy of ET for H₄DPP²⁺(X⁻)₂.

DOI： 10.1002/cptc.202500009

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AIP Publishing  

Introducing heavy atoms, or replacing atoms with heavier ones, is a routine approach for accelerating spin-flipping photophysical processes. However, predicting its impact on phosphorescence efficiency is not straightforward. Herein, we report an unexpected consequence of bromine-to-iodine substitution in a bromothienyl diketone derivative, TIPS-BrTn, that exhibits outstanding room-temperature phosphorescence (RTP) in cyclohexane solution. Contrary to our expectation, the iodo-congener TIPS-ITn exhibited feeble photoluminescence, which we confirmed as RTP by ultrafast spectroscopy. Further experimental and theoretical studies revealed that, in the T1 state, an excited-state symmetry breaking occurred on TIPS-ITn while TIPS-BrTn preserved the centrosymmetric geometry. We identified the driving force for the symmetry breaking as an intramolecular two-center three-electron bonding interaction between iodine and carbonyl oxygen in the (n,π*) excited state. Consequently, while the direct T1–S0 spin–orbit coupling (SOC) in TIPS-BrTn is symmetry-forbidden and zero, that of TIPS-ITn is non-zero due to the loss of centrosymmetry, thereby accelerating nonradiative T1–S0 decay to diminish the RTP. Importantly, the phosphorescence rate constant is not solely dictated by the direct T1–S0 SOC; instead, it can be rationalized by the intensity borrowing from higher singlet states. Thus, our work highlights the importance of controlling molecular symmetry, which could suppress the direct T1–S0 SOC and lead to a preferential acceleration of radiative decay over nonradiative decay for achieving efficient RTP.

DOI： 10.1063/5.0255535

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Language：English   Publisher：Communications Chemistry  

Photoinduced metal-to-ligand (or ligand-to-metal) charge-transfer (CT) states in metal complexes have been extensively studied toward the development of luminescent materials. However, previous studies have mainly focused on CT transitions between d- and π-orbitals. Herein, we report the demonstration of CT emission from 4f- to π-orbitals using a trivalent europium (Eu(III)) complex, supported by both experimental and theoretical analyses. The Eu(III) complex exhibits an eight-coordination structure, comprising three anionic nitrates and two neutral electron-donating ligands containing a carbazole unit. The diffuse reflectance spectrum of the complex displays an absorption band at 440 nm and time-resolved emission analyses reveal a characteristic emission band at 550 nm. Comparative studies employing a trivalent gadolinium (Gd(III)) complex, alongside quantum chemical analyses, confirm that the observed absorption and emission bands are associated with CT transitions between π- and 4f-orbitals. The observation of CT emission based on the 4f-orbital offers novel insights into the field of molecular luminescence science and technology.

DOI： 10.1038/s42004-025-01420-6

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Although a widely used and important industrial chemical, carbon disulfide (CS2) also poses a number of hazards due to its volatility and toxicity. As such, the development of multifunctional materials for the selective capture and easy recognition of CS2 is one of the crucial issues. Herein, we demonstrate completely selective CS2 adsorption among trials involving H2O, alcohols, volatile organic compounds (including thiol derivatives), N2, H2, O2, CH4, CO, NO, and CO2. We also showcase its fine detection using remarkable luminescent response in an Au(I)‐based metal−organic framework (MOF) of {ZnII(pz)[AuI(CN)2]2} (pz = pyrazine; 1) with a two‐fold interpenetration network. Ex situ single crystal X‐ray diffraction for 1 and CS2 accommodated 1 suggested that the Au···Au atoms are not only luminescent centers but also act as interaction sites for CS2 modulating the Au···Au contacts. These experiments revealed the specificity of CS2 and how changes in the CS2‐induced structure. Based on the obtained structural formation, 1 exhibited a sensitive detecting ability for CS2 with an ultrafast response time of less than 10 s. Ex situ time‐resolved photoluminescence analyses developed in this work implied that CS2 varied the energetic relaxation at the excited states related to the luminescent efficiency of the resultant MOF system.

DOI： 10.1002/anie.202413830

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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 of spins with atomic precision and enables the scale-up of individual spins to hierarchical structures. The high designability and extended pore structure of metal-organic frameworks (MOFs) can control interactions between spins and guest molecules. However, the effective design of polarizing radical electron spins by photoexcitation in MOFs has been unexplored. Here, we show that it is possible to effectively hyperpolarize radical electron spins by harvesting mobile excitons in MOFs. As a proof of concept, we introduce 4-carboxy TEMPO molecules as electron spins into MOF-525, which contains an array of porphyrin chromophores, and demonstrate that this light-harvesting MOF system generates a spin-polarized excited quartet state and doublet ground state even by doping a small amount of electron spins. The current material design leads to the creation of highly spin-polarized nanospaces that can be used for quantum sensing and DNP by efficiently generating high-spin polarization in MOFs doped with small amounts of electron spins to prevent spin relaxation.

DOI： 10.1021/jacs.4c14916

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Peripherally unsubstituted dioxadiaza[8]circulene, as the first example of structurally identified pristine hetero[8]circulene, was synthesized by the substituent detachment reactions. The solid-state structures and photophysical properties were analysed to elucidate intermolecular...

DOI： 10.1039/d4cc05539j

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

Abstract

Two‐dimensional perovskites containing an organic fluorophore can be a unique emitter for light‐emitting diodes (LEDs). However, external quantum efficiencies (EQEs) of fluorophore‐containing perovskite LEDs reported thus far are still very low. In this study, these are able to boost the EQE to ≈10% by choosing an organic fluorophore with appropriate energy levels for the perovskite structure organization. In the fluorophore‐containing perovskite LEDs, carrier transport and exciton formation take place in the perovskite's metal halide framework, thereby avoiding the direct formation of nonradiative triplet excitons on the organic fluorophores. Subsequently, the bright triplet excitons formed in the metal halide framework are transferred to form the radiative singlet states of the organic fluorophores, leading to efficient electroluminescence (EL) from the organic fluorophores regularly dispersed inside the perovskite structure. Unexpectedly higher light‐outcoupling efficiency, which is caused by the light scattering in the polycrystalline perovskite layer, will be another reason for efficient EL. These findings will contribute toward the fabrication of LED‐based products with high performance at a low cost.

DOI： 10.1002/adma.202408775

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Publisher：Advanced Functional Materials  

Photomechanical crystals have applications in light-fueled actuators and soft robots. Herein, light-responsive, versatile, anthraquinone dye crystal oscillators actuated via natural vibrations that are resonated by a photothermal effect are described. A black needle-shaped crystal cantilever oscillates at 70 Hz in the first mode of natural vibration upon irradiation by broad-wavelength light ranging from the ultraviolet through the visible to the near-infrared, and also under continuous-wavelength light (400–2000 nm). The second and third natural vibration modes are induced at higher frequencies (530 and 1350 Hz) and evidence complex flagellum-like motions. The frequency can be readily tuned by moving the support of a crystal piece; this is analogous to playing a guitar. The crystal exhibits high durability (more than 10 000 cycles): the high elasticity prevents deterioration. Oscillatory motions can be designed via simulations using finite element analysis. This work will facilitate the use of photomechanical crystals in light-fueled soft robots.

DOI： 10.1002/adfm.202410671

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

Abstract

The singlet fission characteristics of aqueous nanoparticles, self‐assembled from ion pairs of tetracene dicarboxylic acid and various amines with or without chirality, are thoroughly investigated. The structure of the ammonium molecule, the counterion, is found to play a decisive role in determining the molecular orientation of the ion pairs and its regularity, spectroscopic properties, the strength of the intermolecular coupling between the tetracene chromophores, and the consequent singlet fission process. Using chiral amines has led to the formation of crystalline nanosheets and efficient singlet fission with a triplet quantum yield as high as 133% ±20% and a rate constant of 6.99 × 10⁹ s⁻¹. The chiral ion pairs also provide a separation channel to free triplets with yields as high as 33% ±10%. In contrast, nanoparticles with achiral counterions do not show singlet fission, which gave low or high fluorescence quantum yields depending on the size of the counterions. The racemic ion pair produces a correlated triplet pair intermediate by singlet fission, but no decorrelation into two free triplets is observed, as triplet‐triplet annihilation dominates. The introduction of chirality enables higher control over orientation and singlet fission in self‐assembled chromophores. It provides new design guidelines for singlet fission materials.

DOI： 10.1002/advs.202405864

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

Fast room-temperature phosphorescence with high quantum yields up to 38% in solution from metal-free organic 1,2-diketones is reported, along with the mechanism and molecular design principles governing the fast phosphorescence.

DOI： 10.1039/d4sc02841d

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DOI： 10.26434/chemrxiv-2024-n0pd7

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Research Square Platform LLC  

Abstract<p>Photomechanical crystals have applications in light-fuelled actuators and soft robots. Herein, we describe light-responsive, versatile, anthraquinone dye crystal oscillators actuated via natural vibrations that are resonated by a photothermal effect. A black needle-shaped crystal cantilever oscillates at 70 Hz in the first mode of natural vibration upon irradiation by broad-wavelength light ranging from the ultraviolet through the visible to the near infrared, and also under continuous-wavelength light (400–2000 nm). The second and third natural vibration modes are induced at higher frequencies (530 and 1350 Hz) and evidence complex flagellum-like motions. The frequency can be readily tuned by moving the support of a crystal piece; this is analogous to playing a guitar. The crystal exhibits high durability (more than 10,000 cycles): the high elasticity prevents deterioration. Oscillatory motions can be designed via simulations using finite element analysis. This work will facilitate the use of photomechanical crystals in light-fuelled soft robots.</p>

DOI： 10.21203/rs.3.rs-4302535/v1

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Other Link： https://www.researchsquare.com/article/rs-4302535/v1.html

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japanese Photochemistry Association  

<p>Trivalent lanthanide complexes are attractive candidates for light sources due to their exceptionally pure color emission. Enhancing the photoluminescence intensity through sensitization using ligands with high absorption efficiency is a powerful strategy. However, the microscopic energy transfer mechanisms from organic chromophores to lanthanide ions remain elusive. In this study, we investigated the energy transfer processes in luminescent trivalent europium (Eu³⁺) complexes using time-resolved photoluminescence spectroscopy and transient absorption spectroscopy. Our results successfully elucidated the energy transfer processes from two different ligands, revealing that both energy transfers occur via the triplet excited states of each ligand. Based on these findings, we proposed efficient sensitization using host-to-guest energy transfer in a host-guest film composed of aromatic organic molecules and Eu³⁺ complexes. Our approach resulted in a more than 400-fold enhancement of photoluminescence intensity compared to the intrinsic Eu³⁺ complex.</p>

DOI： 10.60391/koukagaku.55.1_34

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

9-[1,4]Benzoxaborino[2,3,4-kl]phenoxaborine-7-yl-1,3,6,8-tetramethyl-9H-carbazole, a donor–acceptor linked TADF molecule with a very short delay lifetime of 750 ns, exhibits a peculiar thermal behavior similar to that of negative gap materials.

DOI： 10.1039/d3fd00151b

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

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Fluorescence imaging, a key technique in biological research, frequently utilizes fluorogenic probes for precise imaging in living systems. Tetrazine is an effective emission quencher in fluorogenic probe designs, which can be selectively damaged upon bioorthogonal click reactions, leading to considerable emission enhancement. Despite significant efforts to increase the emission enhancement ratio (I_AC/I_BC) of tetrazine‐functionalized fluorogenic probes, the influence of molecular aggregation on the emission properties has been largely overlooked in these probe designs. In this study, we reveal that an ultrahigh I_AC/I_BC can be realized in the aggregate system when tetrazine is paired with aggregation‐induced emission (AIE) luminogens. Tetrazine amplifies its quenching efficiency upon aggregation and drastically reduce background emissions. Subsequent click reactions damage tetrazine and trigger significant AIE, leading to considerably enhanced I_AC/I_BC. We further showcase the capability of these ultra‐fluorogenic systems in selective imaging of multiple organelles in living cells. We term this unique fluorogenicity of AIE luminogen‐quencher complexes with amplified dark‐bright states as “Matthew effect” in aggregate emission, potentially providing a universal approach to attain ultrahigh I_AC/I_BC in diverse fluorogenic systems.

DOI： 10.1002/agt2.499

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DOI： 10.1002/adom.202470007

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It is well known that triplet–triplet annihilation upconversion (TTU) can enhance electroluminescence (EL) efficiency by converting two low‐energy triplet excitons into one high‐energy singlet exciton. However, conventional intermolecular TTU requires high doping concentration to activate, limiting device architecture. Here, six dimer molecules comprised of two anthracene units connected by a spacer unit are investigated, which have a possibility of the intramolecular TTU process. As a result, two dimer molecules show high TTU efficiencies close to the theoretical maximum even in dispersed, diluted conditions. By comparing these molecular conformations, a correlation is found between the dimer structures of two anthracene units and the TTU activity in the diluted condition, i.e., the 3D molecular structure with the exciton utilizing efficiency.

DOI： 10.1002/adom.202301924

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Other Link： https://onlinelibrary.wiley.com/doi/pdf/10.1002/adom.202301924

DOI： 10.1002/anie.202307093

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACS Catalysis  

Supramolecular photocatalysts, wherein redox photosensitizer (PS) and catalyst (CAT) molecules are connected to each other, have been extensively studied because of their high photocatalytic activity in both homogeneous and heterogeneous environments compared with the corresponding mixed systems of separated PS and CAT. A supramolecular photocatalyst RuC2PhC2Re, wherein [Ru(diimine)<inf>3</inf>]²⁺ redox PS and fac-[Re(diimine)(CO)<inf>3</inf>{OC(O)OCH<inf>2</inf>CH<inf>2</inf>N(CH<inf>2</inf>CH<inf>2</inf>OH)<inf>2</inf>}] CAT units were spatially separated by a bridging ligand p(-C<inf>2</inf>H<inf>4</inf>)<inf>2</inf>Ph consisting of 8 C-C bonds including a p-phenylene ring, was developed. Although the rate of intramolecular electron transfer of RuC2PhC2Re from one-electron-reduced Ru unit to the Re unit, which is a critical process of photocatalysis proceeding through the bond mechanism, was slower than that of RuC2Re having shorter bridging ligand with an ethylene chain, it could reduce CO<inf>2</inf> to CO with higher durability (TON = 3880) than RuC2Re (TON = 2800). These results clearly suggest that the PS and CAT units can be separated further without lowering photocatalysis of supramolecular photocatalysts because the rate of intramolecular electron transfer is much faster, even in RuC2PhC2Re, than that of the subsequent processes in photocatalytic CO<inf>2</inf> reduction.

DOI： 10.1021/acscatal.3c01407

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Angewandte Chemie International Edition  

We synthesized a (1-propylpyridinium)<inf>2</inf>[ReN(CN)<inf>4</inf>]-type organic–inorganic hybrid exhibiting water-vapor-induced drastic structural changes of the [ReN(CN)<inf>4</inf>]²⁻ assemblies. Specifically, upon exposure to water vapor, dehydrated nitrido-bridged chains were converted to hydrated cyanido-bridged tetranuclear clusters via rearrangements of large molecular building units in the crystals. These switchable assembly forms display substantially different photo-physical properties, although in both cases the emission is caused by a metal-centered d–d transition. The nitrido-bridged chain exhibited a near-infrared (749 nm) emission, which blue-shifted as the temperature increased, while a visible (561 nm) emission and its red shift was demonstrated by the cyanido-bridged cluster.

DOI： 10.1002/anie.202306853

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

A novel Ag-based coordination polymer with a bright phosphorescence originating from metal–metal to ligand charge transfer was synthesized. The Ag⋯Ag-related emission path and structural rigidity resulted in outstanding luminescence efficiency.

DOI： 10.1039/d3cc00179b

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

Singlet fission (SF), converting a singlet excited state into a spin-correlated triplet-pair state, is an effective way to generate a spin quintet state in organic materials. Although its application to photovoltaics as an exciton multiplier has been extensively studied, the use of its unique spin degree of freedom has been largely unexplored. Here, we demonstrate that the spin polarization of the quintet multiexcitons generated by SF improves the sensitivity of magnetic resonance of water molecules through dynamic nuclear polarization (DNP). We form supramolecular assemblies of a few pentacene chromophores and use SF-born quintet spins to achieve DNP of water-glycerol, the most basic biological matrix, as evidenced by the dependence of nuclear polarization enhancement on magnetic field and microwave power. Our demonstration opens a use of SF as a polarized spin generator in bio-quantum technology.

DOI： 10.1038/s41467-023-36698-4

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Other Link： https://www.nature.com/articles/s41467-023-36698-4

Language：English   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publisher：Japan Society for Molecular Science  

<p>As the demands for diverse and complex functionality, the development of photo-functional molecular materials is advanced. In molecules without heavy metals<b>,</b>the electronic excited states can be largely classified into luminescent singlet excited states and non-luminescent triplet excited states. The ability to transition between these two states with vastly different properties through intra/intermolecular electron spin conversion,coupled with the diversity of molecular design, provides a unique advantage in designing photo-functions. Thus, understanding electron spin conversion in molecular systems is fundamentally important from both fundamental science and application perspectives. However, electronic functions are heavily modulated by vibrational degrees of freedom inherent in molecules. Also, study of their photo-functions requires extensive use of time-resolved spectroscopy using ultrafast lasers for capturing the short-lived excited states. Here, several attempts to disentangle the complex molecular excited state dynamics based on ultrafast spectroscopy were introduced. In particular, reverse intersystem crossing and singlet fission are the main topics.</p>

DOI： 10.3175/molsci.17.a0127

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

The solvent effects were studied on charge-transfer excited states in a donor–acceptor-type luminescent material, phenothiazine-triphenyltriazine, which has two distinct conformers: quasi-coplanar and perpendicular conformers. The solvent dielectric permittivity dependence of the steady-state photoluminescence spectra using solvent mixtures of toluene and tetrahydrofuran (THF) indicated that the two conformers have nearly identical excited-state dipole moments. The time-resolved photoluminescence and transient absorption spectra in toluene and THF showed different solvent dependences for the two conformers. A detailed analysis of these time-resolved spectra revealed solvent-dependent emission processes in the two conformers.

DOI： 10.1016/j.cplett.2022.140155

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

Chemical responsivity in materials is essential to build systems with switchable functionalities. However, polarity-switchable materials are still rare because inducing a symmetry breaking of the crystal structure by adsorbing chemical species is difficult. In this study, we demonstrate that a molecular organic-inorganic hybrid crystal of (NEt<inf>4</inf>)<inf>2</inf>[MnN(CN)<inf>4</inf>] (1) undergoes polarity switching induced by water vapor and transforms into a rare example of proton-conducting second-harmonic-generation-active material. Centrosymmetric 1 transforms into noncentrosymmetric polar 1·3H<inf>2</inf>O and 1·MeOH by accommodating water and methanol molecules, respectively. However, only water vapor causes a spontaneous single-crystal-to-single-crystal transition. Moreover, 1·3H<inf>2</inf>O shows proton conduction with 2.3 × 10^-6S/cm at 298 K and a relative humidity of 80%.

DOI： 10.1021/acs.inorgchem.2c02555

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/adom.202101048

Language：English   Publisher：Chemistry A European Journal  

A complex comprising one [Re(CO)<inf>3</inf>]⁺ unit and a phthalocyanine (Pc) ligand (Re<inf>1</inf>Pc) is shown to function as a photo-induced CO-releasing molecule (photoCORM) in the presence of O<inf>2</inf> and a coordinative solvent under irradiation with red light, which can deeply penetrate living tissues. Transient absorption spectroscopic measurements indicate very short excited-state lifetimes and ultrafast intersystem crossing for Re<inf>1</inf>Pc and Re<inf>2</inf>Pc, which contains two [Re(CO)<inf>3</inf>]⁺ units. The excited-state properties are ascribed to efficient spin–orbit coupling and large Franck–Condon factors originating from the complexes’ distorted structures, that is, unsymmetric coordination of [Re(CO)<inf>3</inf>]⁺ unit(s), one of which was confirmed by single-crystal X-ray analysis of a symmetrically substituted Pc with two [Re(CO)<inf>3</inf>]⁺ units. Re<inf>1</inf>Pc represents a promising red-light-driven photoCORM that can be applied in biological environments or therapeutic applications.

DOI： 10.1002/chem.202200716

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/chem.202202281

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/chem.202202281

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

The electronic structure and photophysics of the recently designed organic direct singlet harvesting (DSH) molecule are explored, in which donor (D) and acceptor (A) are held at distance by two bridges. One of the bridges is functionalized with fluorene. This structure leads to an ultrasmall singlet–triplet energy gap of ∆E (S<inf>1</inf>−T<inf>1</inf>) ≈ 10 cm⁻¹ (≈1 meV) between the charge transfer states ^1,3CT and shows an energetically close-lying ³ππ* state localized on fluorene. Dielectric constant variation of the environment leads to state crossing of ³ππ* and ^1,3CT near ε = 2.38 (toluene), as confirmed through time-dependent density functional theory (DFT) and state-specific DFT/polarizable continuum model excited-state calculations. Transient absorption (TA) and time-resolved luminescence in the femtosecond to microsecond regimes show rates of intersystem crossing (ISC) and reverse ISC (rISC) of >10⁹ s^–1. Thus, a strictly mono-exponential short-lived photo-luminescence decay (431 ns) is observed, revealing that rISC is no longer the bottleneck responsible for long thermally activated delayed fluorescence. Ultrafast TA displays a time constant of ≈700 fs, representing the relaxation time of DSH and its solvent environment to the relaxed ¹CT state with a molecular dipole moment of ≈40 D. Importantly, OLED devices, emitting sky-blue light and showing high external quantum efficiency of 19%, confirm that singlet and triplet excitons are harvested efficiently.

DOI： 10.1002/adfm.202201772

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This study reports the facile syntheses of tetra-boron difluoride (tetra-BF2 ) complexes, flag-hinge-like molecules that exhibit intense green-to-orange luminescence in solution and yellow-to-red emission in the solid states. Single-crystal structure analysis and density functional theory calculations suggested a bent structure of this series of compounds. The complexes also exhibited excellent optical properties, with quantum yields reaching 100 % and a large Stokes shift. These properties were attributed to the altered bending angle of the molecule in the S1 excited state. As the rotational motion was suppressed around the 2,2'-bipyrrole axis, atropisomers with axial chirality were formed, which are optically resolvable into (R) and (S)-enantiomers through a chiral column. The atropisomers thus function as circularly polarized luminescent (CPL) materials, in which the color (green, green-yellow, and yellow) can be varied by controlling the aggregation state. This rational design of multi-BF2 complexes can potentially realize novel photofunctional materials.

DOI： 10.1002/anie.202204358

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry ({RSC})  

<jats:p>Novel thermally-activated delayed fluorescence (TADF) materials 2Cz2SB and 2Mi2SB, possessing N-heterocycle and arylsulfonyl groups, were synthesized and their photophysical properties in solution and the solid state were characterized.</jats:p>

DOI： 10.1039/d1tc05196b

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Chemical Society of Japan  

We investigated the correlation between the photophysical properties and detailed excited-state characteristics of a multiple-resonance-type thermally activated delayed fluorescence (TADF) molecule, DABNA-1, using time-resolved infrared vibrational spectroscopy. By comparing the distinctive vibrational spectra in the fingerprint region (10001700 cm¹¹) to the simulated spectra, we found the optimal calculation conditions for density functional theory calculations to retrieve the vibrational spectra. Based on the calculations, the excited-state geometries and molecular orbitals in the lowest excited singlet (S<inf>1</inf>) and triplet (T<inf>1</inf>) states, as well as the ground state (S<inf>0</inf>), were determined. Consequently, we revealed that the similarity between the potential surfaces of T<inf>1</inf> and S<inf>0</inf> suppressed non-radiative decay and improved the high fluorescence quantum yield via TADF. Furthermore, we calculated the spin-orbit coupling matrix elements (SOCMEs) considering the experimentally confirmed geometries, and revealed that twisting of the main skeleton increases the SOCMEs.

DOI： 10.1246/bcsj.20210403

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry ({RSC})  

<jats:p>The highest efficiency of heavy metal-free visible-to-UV photon upconversion is achieved by employing a ketocoumarin sensitizer with strong visible absorption, weak UV absorption, and high intersystem crossing efficiency.</jats:p>

DOI： 10.1039/D1TC05526G

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Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Advanced Optical Materials  

In organic microcavities, a macroscopic condensate of exciton-polaritons can be formed at high-exciton polariton densities. The threshold for forming this condensate is proportional to the relaxation rate from initially excited excitons to these polaritons and the lifetime of the lowest energy polariton states. Although the influence of the lower polariton (LP) lifetime on the threshold has been studied, the relationship between the polariton relaxation rate and the threshold has not been fully explored. In this study, a room-temperature polariton condensate is demonstrated at a threshold pump fluence of 9.7 ± 0.1 µJ cm⁻², in a microcavity containing 4,4″-bis((E)-4-(3,6-bis(2-ethylhexyl)-(9H-carbazol-9-yl))styryl)-1,1″-biphenyl (BSBCz-EH). By using a semiclassical model to describe the polariton kinetics, it is revealed that this low threshold results from the rapid relaxation rate from the dark exciton reservoir to the set of the LP states forming the condensate, with an effective rate W<inf>ep</inf> ≈ 2.0 × 10⁻⁵ cm³ s⁻¹. These results show that accelerating polariton relaxation is possible and is an important factor for realizing low-threshold polariton condensates.

DOI： 10.1002/adom.202102034

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Other Link： https://doi.org/10.1002/adom.202102034

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DOI： 10.1021/acs.inorgchem.1c00146

Other Link： https://doi.org/10.1021/acs.inorgchem.1c00146

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DOI： 10.1039/D1SC02213J

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1039/d1sc02213j

Other Link： https://doi.org/10.1039/d1sc02213j

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DOI： 10.1021/acs.inorgchem.1c00702

Other Link： https://doi.org/10.1021/acs.inorgchem.1c00702

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DOI： 10.1021/acs.jpca.0c09337

Other Link： https://doi.org/10.1021/acs.jpca.0c09337

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DOI： 10.1039/d0cc05462c

Other Link： http://dx.doi.org/10.1039/d0cc05462c

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DOI： 10.1039/C9CC09062B

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DOI： 10.1021/acsnano.9b03060

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1038/s41467-018-07972-7 |

Other Link： https://www.nature.com/articles/s41467-018-07972-7

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/adma.201707312

Other Link： https://onlinelibrary.wiley.com/doi/full/10.1002/adma.201707312

Language：Japanese   Publishing type：Research paper (scientific journal)  

Other Link： https://www.jove.com/video/57612/novel-techniques-for-observing-structural-dynamics-photoresponsive

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/acs.jpcc.8b00476

Other Link： https://pubs.acs.org/doi/abs/10.1021/acs.jpcc.8b00476

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DOI： 10.1021/acsenergylett.7b00717

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DOI： 10.1126/sciadv.1602388

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DOI： 10.1021/jacs.6b13089

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DOI： 10.1002/adma.201603072

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DOI： 10.1021/acscentsci.6b00063

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DOI： 10.1021/acs.jpcc.5b12686

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DOI： 10.7567/JJAP.52.062401

Other Link： https://iopscience.iop.org/article/10.7567/JJAP.52.062401

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DOI： 10.1039/c3cp54157f

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/978-3-319-13242-6_52

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Country：Japan  

Event date： 2023.3

Language：English   Presentation type：Oral presentation (general)  

Venue：online   Country：Japan  

Event date： 2022.12

Language：Japanese  

Venue：オンライン   Country：Japan  

Event date： 2022.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Fukuoka   Country：Japan  

Event date： 2022.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Fukuoka   Country：Japan  

Event date： 2022.7

Language：English   Presentation type：Oral presentation (general)  

Venue：Glasgow   Country：United Kingdom  

Event date： 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.6

Language：Japanese  

Country：Japan  

Event date： 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2020.1

Language：English   Presentation type：Oral presentation (general)  

Venue：Shanghai, China   Country：Japan  

Other Link： http://acup2020.htcis.net/

Event date： 2019.12

Language：Japanese   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：東京   Country：Japan  

Event date： 2019.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：札幌   Country：Japan  

新しい社会的ニーズにこたえるため、分子性材料の開発。有効利用重要性はますます増しているが、それらを支える基盤研究が必ずしも十分でない。特に光が絡んだ現象は超高速分光を駆使した実時間解析が強力である。ここでは、発表者が過去に携わってきた最先端の知見を応用物理学会の聴衆に向けて発信した。

Event date： 2019.7

Language：English   Presentation type：Oral presentation (general)  

Venue：Wako, Saitama   Country：Japan  

Other Link： https://cems.riken.jp/topicalmeeting/orgphotoelec2019/

Event date： 2019.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Ritsumeikan University   Country：Japan  

Event date： 2019.1

Language：English   Presentation type：Oral presentation (general)  

Venue：Brisbane   Country：Australia  

Event date： 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋   Country：Japan  

Event date： 2018.7

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：福岡   Country：Japan  

Event date： 2018.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：札幌   Country：Japan  

オプトエレクトロニクスで重要となっている新規材料鉛ハライドペロブスカイト半導体について、独自に開発した時間分解で構造ダイナミクスに関する情報を得ることができる時間分解カー効果分光を適用することで物性の理解を提案した発表。特に誘電関数の特異性に注目して物性を整理した点が特徴である。

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Event date： 2025.1

Event date： 2024.12

Event date： 2024.10

Event date： 2024.9

Event date： 2024.7

Event date： 2024.7

Event date： 2024.6

Event date： 2024.3

Presentation type：Oral presentation (invited, special)  

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Event date： 2024.1

Presentation type：Oral presentation (invited, special)  

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Event date： 2023.12

Presentation type：Oral presentation (invited, special)  

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Event date： 2023.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都   Country：Japan  

Event date： 2023.10

Presentation type：Oral presentation (invited, special)  

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Event date： 2023.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2023.9

Presentation type：Poster presentation  

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Event date： 2023.9

Language：Japanese  

Venue：広島   Country：Japan  

Event date： 2023.8 - 2023.9

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Event date： 2023.8

Presentation type：Oral presentation (general)  

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Event date： 2023.8 - 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Fukuoka   Country：Japan  

Event date： 2023.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：山梨大学   Country：Japan  

Event date： 2023.7

Presentation type：Oral presentation (general)  

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Event date： 2023.7

Language：English   Presentation type：Oral presentation (general)  

Venue：Sapporo   Country：Japan  

Event date： 2023.5

Language：English  

Venue：福岡   Country：Japan  

Event date： 2023.5

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2023.3

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2023.1

Presentation type：Oral presentation (invited, special)  

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Event date： 2023.1

Language：Japanese  

Venue：福岡   Country：Japan  

Event date： 2022.12

Language：Japanese  

Venue：東京   Country：Japan  

Event date： 2022.12

Language：English  

Venue：online   Country：Japan  

Event date： 2022.11

Language：English   Presentation type：Oral presentation (general)  

Venue：online   Country：Japan  

Event date： 2022.9

Language：Japanese  

Venue：横浜   Country：Japan  

Event date： 2022.9

Language：Japanese  

Country：Japan  

Event date： 2022.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.7

Language：English   Presentation type：Oral presentation (general)  

Venue：online   Country：Japan  

Event date： 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2020.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2020.12

Language：Japanese  

Venue：オンライン   Country：Japan  

Event date： 2020.11

Language：Japanese  

Venue：オンライン   Country：Japan  

Event date： 2020.9

Language：English   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2020.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2020.1

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学   Country：Japan  

Event date： 2019.12

Language：Japanese  

Venue：和光市   Country：Japan  

Event date： 2019.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山   Country：Japan  

Event date： 2019.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九重、大分県   Country：Japan  

Other Link： http://www.scc.kyushu-u.ac.jp/Kouzou/kuju2019/index.html

Event date： 2019.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Qiandao Lake   Country：China  

Event date： 2019.3

Language：Japanese  

Venue：九州大学   Country：Japan  

Event date： 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：千葉大学   Country：Japan  

Event date： 2019.2 - 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪大学　産業科学研究所   Country：Japan  

Event date： 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Event date： 2018.9

Language：Japanese  

Venue：関西学院大学   Country：Japan  

Event date： 2018.6

Language：Japanese  

Country：Japan  

Event date： 2018.6

Language：Japanese  

Country：Japan  

Event date： 2017.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Boston, MA   Country：United States  

Event date： 2017.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：San Diego, CA   Country：United States  

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Photofunctional materials based on rare earth ions have attracted much attention because they demonstrate unique properties that cannot be achieved by other materials. However, the microscopic mechanisms that lead to the unique functions have not necessarily been clarified, which is a challenge for further material design. Although it is important to understand the excited state/carrier dynamics that occur in the material after light absorption, it is not easy to capture the elementary processes experimentally because the processes after photoexcitation proceed on very fast time scales such as pico- or nano-seconds. We are tackling these challenges by successfully applying ultrafast time-resolved spectroscopy with a home-built instrument constructed using a femtosecond ultrashort pulsed laser (time duration ~100 fs). In this talk, we will introduce some of the issues we have been working on in our laboratory, such as (1) ultrafast photocarrier trapping processes in inorganic materials containing Eu(II) ions that exhibit mechano-luminescence properties, and (2) ultrafast spectroscopic approaches to the intramolecular energy transfer of lanthanide trivalent complexes for highly luminescent materials.

Language：English  

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Type：Competition, symposium, etc. 

Number of participants：2,500

Type：Competition, symposium, etc. 

Number of participants：2,700

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：7

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：3

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：2

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：2

Audience：General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Seminar, workshop

Audience：Infants,　Schoolchildren,　Junior students,　High school students

Type：Seminar, workshop

Audience：Infants,　Schoolchildren,　Junior students,　High school students

Type：Seminar, workshop

Audience：Infants,　Schoolchildren,　Junior students,　High school students

Type：Seminar, workshop

Audience：Infants,　Schoolchildren,　Junior students,　High school students

Type：Seminar, workshop

Audience：Infants,　Schoolchildren,　Junior students,　High school students

Type：Seminar, workshop

Audience：Infants,　Schoolchildren,　Junior students,　High school students

Type：Seminar, workshop

Audience：General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Lecture

Audience：Infants,　Schoolchildren,　Junior students,　High school students

Type：Other

Audience：General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Lecture

Audience：General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Lecture

Audience：General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Lecture

Audience：General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Lecture

Audience：General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Lecture

Audience：General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Lecture

Audience：General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Lecture

バーチャルシンポジウム形式で最先端の科学を誰でmおいつでも聞ける形で発信し、緊急事態下での新たな学びの場を提供した。企画うから担当し、二週間の準備期間で日程・プログラムの確定と当日のファシリテータまで遂行した。

Audience：General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Lecture

Audience：General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Seminar, workshop

Audience：Infants,　Schoolchildren,　Junior students,　High school students

Type：Seminar, workshop

Audience：General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Seminar, workshop

Audience：General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Lecture

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