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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]

The aryl phosphine oxide (APO) groups have been widely studied as host materials in organic light-emitting diodes (OLEDs). However, their application as emissive materials has been rarely explored, especially in the preparation of nondoped devices. In this work, two hybridized local and charge-transfer (HLCT) molecules, 2 t BuCz-APO and 2TPA-APO , are developed by incorporating the donor groups tert -butylcarbazole (t Cz) and diphenylamine (DPA) into phosphafluorene oxide unit. The experimental results demonstrate that phosphafluorene oxide derivatives exhibit HLCT characteristics, marking the first time that HLCT characteristics have been realized based on APO. As a result, the nondoped OLED based on 2 t BuCz-APO exhibits the best performance with an excellent maximum external quantum efficiency (EQE max) of 7.3 % and Commission Internationale de l'Éclairage (CIE) coordinates of (0.14, 0.15). This molecular design strategy has demonstrated that phosphine oxide, as an acceptor unit, shows promising potential for the development of highly efficient nondoped OLEDs. [Display omitted] • The first fluorescent emitter with HLCT characteristics based on APO as the acceptor. • External quantum efficiency improvement is achieved by "hot exciton" channel. • The nondoped OLED based on 2 t BuCz-APO exhibits an excellent EQE max of 7.3 % and CIE coordinates of (0.14, 0.15). [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]