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Two 2-substituted 8-hydroxyquinoline ligands ( HL 1 and HL 2 ) containing a cyano group were synthesized and characterized by ESI-MS, NMR spectroscopy and elemental analysis (EA). Solvothermal reactions of the two ligands with ZnX 2 and CdX 2 (X − : NO 3 − and OAc − ) salts afforded three luminescent complexes, i.e., monomeric Zn(II) complex [Zn(L 1 ) 2 ] ( 1 ), trimeric Zn(II) complex [Zn 3 (L 2 ) 6 ] ( 2 ) and tetrameric Cd(II) complex [Cd 4 (L 2 ) 8 ] ( 3 ). These three complexes were characterized by single crystal X-ray diffractions, powder X-ray diffractions (PXRD), thermogravimetry analyses (TGA) and EA, illustrating a lamellar structure facilitated by noncovalent interactions such as aromatic π⋯π stacking and C–H⋯N H-bonds. Further investigations by UV–Vis, photoluminescence (PL) and fluorescence lifetime reveal tunable luminescence from yellow to red among 1 – 3 in the solid state. [ABSTRACT FROM AUTHOR]

One novel tetranuclear Cd(II) complex with formula [Cd 4 L 6 (NO 3 ) 2 ] ( 1 ) is accessible by solvothermal reaction of Cd(NO 3 ) 2 with a ( E )-2-[2-(3-thienyl)ethenyl]-8-quinolinol ligand ( HL ), which was characterized by means of 1 H NMR, ESI-MS, elemental analysis, IR and TGA. X-ray structural analysis indicated that 1 exhibited a double open cubane-like core structure, which was bridged by six 8-hydroxyquinolinate-based ligand. Rich aromatic stacking interactions and non-classical C–H···O weak interactions sustain the packing structure. The coordination behavior of cadmium salt and HL in solutions was performed by UV–vis and photoluminescence (PL). The experimental results corroborate that emission spectrum of the title complex in the solid state at room temperature gives strong yellow-green luminescence. In addition, the thermal stability, fluorescent lifetime, electronic calculation and quenching behaviors of C 60 and EtBr-DNA interacted with the compound were also investigated. [ABSTRACT FROM AUTHOR]

Thermally activated delayed fluorescence (TADF) dyes are promising for applications like bioimaging, sensing, and optoelectronic devices due to their efficient exciton utilization without noble metals, making them ideal for organic light-emitting diodes (OLEDs). In this contribution, we introduce a new TADF emitter, 3-(9,9-dimethylacridin-10(9 H)-yl)-12 H -chromeno[2,3- b ]quinolin-12-one (CQLO-DMAC), which incorporates an intramolecular oxygen-locked azaryl ketone acceptor, CQLO. This design enhances molecular rigidity and electron-accepting strength. The CQLO-DMAC compound, featuring a bulky donor, shows significant intramolecular charge transfer and TADF emission. Comprehensive analyses, including spectroscopic studies and theoretical calculations, reveal high luminescence efficiency and reduced non-radiative losses. Utilizing CQLO-DMAC in OLEDs, we achieved a green-yellow emission peak at 548 nm and a maximum external quantum efficiency of 17.4 %. The findings highlight the potential of CQLQ as a highly effective acceptor in designing of TADF electroluminescent dyes. [Display omitted] • An oxygen-locked azaryl ketone acceptor CQLO is designed for constructing TADF emitter (CQLO-DMAC). • CQLO-DMAC exhibits notable TADF properties, facilitating efficient triplet-to-singlet spin conversion. • CQLO-DMAC demonstrates bright TADF emission with a decent PLQY of 72 %. • High electroluminescence efficiency with an EQE of up to 17.4 % are demonstrated. [ABSTRACT FROM AUTHOR]

A novel red thermally activated delayed fluorescence (TADF) emitter, 2-(4,4″-bis(diphenylamino)-[1,1':3′,1″-terphenyl]-4′-yl) quinoxaline-6,7-dicarbonitrile (QCN-2TPA), was developed by incorporating two trianiline units into the ortho- and para-positions of the quinoxalin-6,7-dinitrile core. The adjacent trianiline unit and quinoxalin-6,7-dinitrile core interact spatially for through-space charge transfer, while the quinoxalin-6,7-dinitrile core and the para-positioned trianiline unit enable through-bond charge transfer. QCN-2TPA demonstrated high photoluminescence quantum efficiency and a small Δ E ST. Organic light-emitting diodes using QCN-2TPA as the emitter achieved a maximum external quantum efficiency of 21.4 % with red emission peaking at 596 nm. [Display omitted] • The novel emitter simultaneously demonstrates both TSCT and TBCT characteristics. • The emitter shows red emission with distinct TADF property. • The QCN-2TPA -based OLED achieves a higher EQE of 21.4 % compared to its counterparts. [ABSTRACT FROM AUTHOR]

The study presents the design, synthesis, and characterization of DCNP-2TPA, a novel "hot exciton" fluorophore featuring a donor-acceptor structure combining dicyanophenanthrene and triphenylamine. Through a comprehensive analysis including structural examination, theoretical modeling, and optical assessments, the suitability of DCNP-2TPA for integration into organic light-emitting diodes (OLEDs) is evaluated. Comparative to existing dicyanophenanthrene-based emitters, DCNP-2TPA demonstrates significantly enhanced luminescence efficiency, by virtue of the incorporation of two triphenylamine moieties with moderate electron-donating strength. Furthermore, DCNP-2TPA exhibits aggregation-induced emission (AIE) properties and showcases hybridized local and charge-transfer (HLCT) excited states, offering an efficient "hot exciton" channel for triplet harvesting. Employing DCNP-2TPA as the emissive core, OLED devices achieve a noteworthy external quantum efficiency of 8.42 %, highlighting the promise of DCNP-2TPA as an efficient candidate for OLED applications. [Display omitted] • A new "hot exciton" fluorophore, DCNP-2TPA, based on dicyanophenanthrene is developed. • DCNP-2TPA demonstrates superior luminescence efficiency with a quantum yield of 98 %. • DCNP-2TPA exhibits aggregation-induced emission and hybridized local and charge-transfer excited states. • DCNP-2TPA OLED exhibits efficient electroluminescence with external quantum efficiency of 8.42 %. [ABSTRACT FROM AUTHOR]

Polyethylene oxide (PEO) electrolytes have been extensively researched in solid-state batteries due to their excellent interface compatibility, high flexibility, and ease of machining. However, its practical application is still hindered by low ionic conductivity (∼10−6 S cm−1 at room temperature) and a narrow electrochemical stability window. To settle these shortcomings, a PEO-based composite electrolyte enabled by active LiGaO 2 filler and 1-allyl-3-methylimidazolium bis(trifluoromethyl sulfonyl)imide (AMIm-TFSI) ionic liquid is constructed for lithium metal batteries (LMBs). Benefiting from the synergistic effect of LiGaO 2 filler and AMIm-TFSI ionic liquid, this composite electrolyte not only enhances the ionic conductivity (2.08 × 10−3 S cm−1) and electrochemical window (5.2 V vs. Li+/Li) but also reduce the interfacial impedance. Furthermore, the Li//Li symmetric cells achieved an ultralong lithium deposition/stripping cycle over 1000 h at 0.1 mA cm−2. The assembled solid-state LiFePO 4 //Li cell exhibit superior rate capability (164.2, 158.5, 154.8, 148.6, 119.4 mAh g−1 at 0.1, 0.2, 0.5, 1, and 2 C, respectively) and excellent cycling stability (147.3 mAh g−1 after 300 cycles at 0.2C). The X-ray photoelectron spectroscopy (XPS) analysis reveals that the composite electrolytes in situ form an inorganic-rich solid electrolyte interface layer. This work provides guidance on designing superior organic-inorganic composite electrolytes for LMBs. [Display omitted] • PIL-CSE enabled by the synergistic effect of LiGaO 2 filler and IL for superior LMBs. • PIL-CSE achieved 2.08 × 10−3 S cm−1 at 60 °C and an electrochemical window >5.2 V. • XPS analysis reveals that PIL-CSE could in situ form an inorganic-rich SEI film. • The LiFePO 4 /PIL-CSE/Li exhibited a superior rate capability and cycling stability. [ABSTRACT FROM AUTHOR]

[Display omitted] Haloalkynes that could be accessed from diverse precursors, are versatile in synthetic chemistry as alkynylation and/or halogenation reagents, enabling concise and divergent delivery of functional molecules in selective manners. Recently, additional reactivity and substrate scope of haloalkynes, was also developed, facilitating expedient delivery of fused heterocycles. [ABSTRACT FROM AUTHOR]

The utilization of triplet state excitons is important for the efficiency of organic light-emitting diodes (OLEDs). In this work, two isomers ( p -PIAnPO and m -PIAnPO) of anthracene-based derivatives with triphenylphosphine oxide (PO) and phenanthroimidazole (PI) in different positions were designed and synthesized. In particular, PO provides large spatial hindrance and promotes hole transport, and PI has excellent bipolar transport ability, which helps to balance carrier transport. The para- linkage ( p -PIAnPO) favors conjugation expansion and achieves high luminescence efficiencies, whereas the meta- linkage ( m -PIAnPO) provides a highly twisted molecular conformation, thus effectively interrupting conjugation and leading to deep-blue emission. These molecules exhibit excellent thermal stability and efficient electroluminescence properties. Non-doped OLEDs using p -PIAnPO and m -PIAnPO as the light-emitting layers achieve maximum external quantum efficiencies of 6.0% and 4.2% with the λ EL at 466 nm and 448 nm, corresponding to high exciton utilization efficiency (EUE) of 59%–88% and 54%–81%. In addition, p -PIAnPO-based OLEDs achieve an ultra-low efficiency roll-off of 1.7% at 1000 cd m−2. Theoretical calculations and experimental results show that the high EUE is mainly attributed to the high-lying reverse intersystem crossing from T 3 to S 1 namely hot exciton channel. • Large steric hindrance group PO inhibits exciton quenching. • PO improves hole transport performance. • An promises high luminescence efficiency. • OLED of p -PIAnPO with 466 nm emission and extremely low efficiency roll-off of 1.7% at 1000 cd m−2. [ABSTRACT FROM AUTHOR]

Organic luminophores of narrowband emission are considered a filter-less light resource, promising for high-resolution organic light-emitting diode (OLED) display technology. It is essentially feasible to achieve narrowband emission by manipulating the intrinsic structural relaxation and vibronic coupling in the excited state. On this basis, by the introduction of single bond-linked peripheral moieties of 4-methoxyphenyl into the benzo[c]benzo [7,8]quinolino[1,2,3-fg]acridine-7,11-dione (BAO) core, the resulting BAO-PMO is observed to exhibit better performance, achieving a full width at half-maximum (FWHM) of down to 27 nm/0.14 eV in toluene for the narrowest band compared with that of BAO (35 nm/0.20 eV). An effective strategy is thus proposed by the significant enhancement of the low-frequency vibronic coupling strength with simultaneous mitigation of the high-frequency ones to realize the control of structural relaxation. In consequence, the BAO-PMO based OLED device exhibits a narrowband green emission with an FWHM of 37 nm/0.18 eV. • Organic narrowband luminophores based on carbonyl-bridged triarylamine were shown. • The emission narrowing was achieved via vibronic coupling regulation of the excited-state configuration. • Doped OLEDs exhibit narrowband green emission with a full width at half-maximum of down to 37 nm. [ABSTRACT FROM AUTHOR]

Blue fluorescent materials are an essential part of commercial OLED displays and lightings. However, the market lacks highly efficient, short-emission wavelength blue fluorescent materials. Herein, two new blue fluorescent materials, SAFPI-3 and SAFPI-2, are developed based on a phenanthroimidazole derivative and spiro fluorene triphenylamine by replacing the substitution sites, which tactfully utilize the spatial configuration of the molecules to achieve higher external quantum efficiency and a shorter emission wavelength at the same time. Furthermore, the versatility of SAFPI-3 and SAFPI-2 can be demonstrated as non-doped emitters for blue OLEDs and as the hosts of yellow phosphorescent OLEDs, which have achieved a high external quantum efficiency of 23.98% with extremely low-efficiency roll-off. [Display omitted] • Two novel blue fluorescent isomers are developed. • SAFPI-3 -based non-doped OLED achieves a high EQE of 4.99% with EL emission peak at 432 nm. • OLED using SAFPI-3 as host obtains high EQE of 23.98% with negligible efficiency roll-off. [ABSTRACT FROM AUTHOR]

Photoinduced polymerization with low-energy, longer wavelength light has attracted enormous attention in material/biological applications owing to its unique advantages of greener and deep curing compared to conventional harsh UV-triggered polymerization. However, the low-energy polymerization methods often rely on heavy atom-containing sensitizers or suffer from the slow solidification process, which restricts their applicability in several areas. Herein we construct a novel efficient photoinitiating system based on a single-atom substituted pure organic triplet photosensitizer, prepared from a common naphthalimide chromophore through a simple one-pot process, and exemplified its potential to enable the efficient and rapid polymerization (just a few tens of seconds) of acrylate upon low-intensity (0.36 W/cm2) red-light illumination. We show that the single atom replacement (oxygen with sulfur) can redshift the absorption profile of naphthalimide chromophore over 150 nm and also effectively promotes its intersystem crossing efficiency (from 0 to 86.4%). For the first time, the thionaphthalimide (NIS) was introduced in triplet-triplet annihilation upconversion, showing a high upconversion quantum yield of (4.4–12.9%) with a large anti-Stokes shift (0.65–0.80 eV) in various solvents. We successfully employed the upconverted annihilator's singlet to trigger the photoinitiator via Förster resonance energy transfer (FRET) for polymerization. Furthermore, this photoinitiating system is found to be effective enough to be operable under sunlight illumination and useful for the fabrication of high-quality flexible products via photolithography approach. Thus, our results are beneficial for the future design of eco-friendly, low-energy activated chemical conversion systems. A single-atom substituted pure organic photosensitizer was selected for the first time to combine with an annihilator perylene in triplet-triplet annihilation upconversion systems that efficiently derives polymerization of acrylate upon low-intensity red illumination. [Display omitted] • Select an easy to synthesis single-atom substituted naphthalimide to form polymer. • Develop a novel efficient TTA upconversion-based photoinitiating system. • Realization of efficient polymerization upon low-intensity red illumination. • Exploration of triplet-triplet annihilation (TTA)-induced polymerization mechanism. [ABSTRACT FROM AUTHOR]

Graphical abstract Two 8-hydroxyquinoline based ligands, (E)-2-[(4-tert-butylphenyl)ethenyl]-8-hydroxyquinoline (L 1) and (E)-2-[(2-chloro-3,4-dimethoxyphenyl)ethenyl]-8-hydroxyquinoline (L 2) as well as their zinc(II) and cadmium(II) complexes, namely Zn 2 (L 1) 4 , Cd 3 (L 1) 6 , Zn 3 (L 2) 6 and Cd 3 (L 2) 6 were designed and synthesized. Characterizations including X-ray crystallography, NMR spectra, UV–Vis and fluorescence spectroscopic titrations, thermogravimetric analysis as well as theoretical calculation were used to study their photophysical properties. Abstract Two novel C-2 position modified 8-hydroxyquinoline ligands, (E)-2-[(4-tert-butylphenyl)ethenyl]-8-hydroxyquinoline (L 1) and (E)-2-[(2-chloro-3,4-dimethoxyphenyl)ethenyl]-8-hydroxyquinoline (L 2) as well as their zinc(II) and cadmium(II) complexes, namely Zn 2 (L 1) 4 , Cd 3 (L 1) 6 , Zn 3 (L 2) 6 and Cd 3 (L 2) 6 were designed and synthesized. Thanks to the introduction of aromatic tert-butyl and methoxy, ligands L 1 and L 2 are highly soluble and complexes are having good solubility in dimethyl sulfoxide (DMSO) and chloroform. X-ray structural analysis indicate four complexes were in P 21/ c , P 2/ c , P 1 ¯ , C 2/ c space group, respectively, and exhibit a monoclinic crystal system except Zn 3 (L 2) 6 , which hold a triclinic crystal system. Structural formulea and coordinating behavior of these complexes were also investigated by NMR, UV–Vis and fluorescence spectroscopic titrations in solution, revealing four complexes were well coordinated. Solid state photoluminescence studies reveal they emit strong yellow-orange luminescence at 568–612 nm with 5.47–11.79 ns lifetime. Thermogravimetric and theoretical electronic structure analysis indicate that four complexes appear to be promising candidates for the application as yellow luminescent materials. [ABSTRACT FROM AUTHOR]