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Developing highly sensitive optical thermometers is of great significance due to their capability to enable remote and non-contact temperature measurements, rendering them highly applicable in diverse and harsh environments. Herein we report a temperature-dependent phosphor of 0D metal halide hybrid by incorporating Bi3+ into the (MePPh3)2ZnCl4 matrix. Through Bi3+ doping, the initially non-luminescent (MePPh3)2ZnCl4 matrix exhibits a deep-blue emission centered at 453 nm, with a photoluminescence quantum yield (PLQY) of 5.71% and a Stokes shift of 75 nm at room temperature. Experimental characterization demonstrates that exciton-like luminescence of Bi3+ is mainly responsible for the blue emission. Single crystals of Bi3+-doped (MePPh3)2ZnCl4 show an unusual correlation between photoluminescence (PL) lifetime and temperature. Particularly, the dependence of luminescence lifetime on temperature is most remarkable in the temperature range of 80 to 100 K with an exceptional sensitivity up to 0.09 K−1, representing one of the best levels for thermometry based on PL decay lifetime. Our work not only provides a viable strategy for designing a novel, environmentally friendly, and stable blue emitter, but also paves the way for precise thermometric application at low temperature. [ABSTRACT FROM AUTHOR]

It is imminent to develop phosphors with multiple stimuli responses due to the increasing demand on anti‐counterfeiting and information encryption technologies. Here, a zero dimensional (0D) organic–inorganic hybrid (DPPE)2MnBr4·H2O (DPPE = 4,4‐Difluoropiperidine, 1), which emits green light and exhibits reversible thermo‐ and vapor‐luminescence responses to heat and organic solvents is reported. Specifically, when heated above 100 °C for 30 s, hybrid 1 transforms into yellow‐emitting hybrid 2. Upon exposure to dichloromethane (DCM), it transforms into a red‐emitting hybrid 3. Experimental analysis reveals that Mn2+‐Mn2+ magnetic coupling interactions and coordination configuration transformation are responsible for the obvious switching of photoluminescence. Owing to its extraordinary triple‐mode switching characteristics, enabling luminescence‐adjustable transformations such as green to yellow, green to red, and yellow to red emission, this metal‐halide hybrid is promising for the application in anti‐counterfeiting and information encryption. [ABSTRACT FROM AUTHOR]

Circularly polarized electroluminescence (CPEL) is an active area of research because of its wide application in 3D displays and anti‐counterfeiting. However, it is not trivial to obtain a high asymmetry factor for highly efficient CPELs. Herein, a highly efficient CPEL is demonstrated with a superior asymmetry factor by using a chiral phosphine‐oxide‐passivated perovskite film as an emitter. An in situ‐formed perovskite nanocrystalline (NC) film is obtained by passivation of the chiral phosphine oxide. The as‐formed film exhibits much‐enhanced photoluminescence compared with the pristine film. More importantly, the NC film exhibits excellent chiral photoluminescence with a luminescence dissymmetry factor glum as high as 5.6 × 10−3. Electrically driven light‐emitting diodes based on the NC film exhibited superior device performance with a maximum brightness of 18,783 cd m−2 and a peak external quantum efficiency of 3.6%. More encouragingly, an unprecedented electroluminescence asymmetry factor gEL of up to 0.18 is achieved because of the chiral lattice distortion of the perovskite, which is the state‐of‐the‐art among hybrid materials. [ABSTRACT FROM AUTHOR]

Metal halides are considered as an emerging class of X-ray scintillation materials with typical advantages of high-resolution scintillating imaging, low-cost and facile preparation. Here, we report ultra-high spatial resolution X-ray imaging by using a 2D copper(I)-based cluster (CISDM)4[Cu4I8]·2H2O (CISDM = cis-2,6-dimethylmorpholine) as a scintillator material. Thin single crystals were grown by slowly evaporating a solution containing CuI and CISDMI, and determined as a 2D layered structure with the [Cu4I8]4− cluster polyhedrons connected to each other and surrounded by CISDM cations. 2D (CISDM)4[Cu4I8]·2H2O exhibits bright yellow luminescence at 588 nm and a photoluminescence quantum yield as high as 87.2%. X-ray scintillation investigation shows that this 2D hybrid displays a good linear response to X-ray dose rates and a light yield of about 41 042 photons MeV−1 as well as a low detection limit of 86.8 nGy s−1. Most encouragingly, it gives an exceptional spatial resolution of 108 lp mm−1, representing the state of the art value among those of the reported lead-free metal halide hybrids. Our work provides a design concept of copper(I)-based single crystals for the application in high spatial resolution scintillators. [ABSTRACT FROM AUTHOR]

Low‐dimensional (low‐D) organic metal halide hybrids (OMHHs) have emerged as fascinating candidates for optoelectronics due to their integrated properties from both organic and inorganic components. However, for most of low‐D OMHHs, especially the zero‐D (0D) compounds, the inferior electronic coupling between organic ligands and inorganic metal halides prevents efficient charge transfer at the hybrid interfaces and thus limits their further tunability of optical and electronic properties. Here, using pressure to regulate the interfacial interactions, efficient charge transfer from organic ligands to metal halides is achieved, which leads to a near‐unity photoluminescence quantum yield (PLQY) at around 6.0 GPa in a 0D OMHH, [(C6H5)4P]2SbCl5. In situ experimental characterizations and theoretical simulations reveal that the pressure‐induced electronic coupling between the lone‐pair electrons of Sb3+ and the π electrons of benzene ring (lp‐π interaction) serves as an unexpected "bridge" for the charge transfer. Our work opens a versatile strategy for the new materials design by manipulating the lp‐π interactions in organic–inorganic hybrid systems. [ABSTRACT FROM AUTHOR]

Ultra‐long room temperature phosphorescence (ULRTP) materials show valuable applications in encryption, biological imaging, and many other fields. Amazingly, the concomitant impurities from raw materials that are normally ignored contribute dramatically to the ULRTP. In this study, CzPMB [9‐(4‐bromo‐3‐methylphenyl)‐9H‐carbazole] with phosphorescent quantum efficiency of 64% is prepared from commercial carbazole, but the phosphorescent efficiency is drastically reduced to < 2% once trace impurity (5‐(4‐bromo‐3‐methylphenyl)‐5H‐benzo[b]carbazole) is separated. HPLC studies demonstrated the separated impurity is a byproduct derived from trace benzocarbazole in commercial carbazole. Subsequently, the ULRTP for the CzPMB synthesized from lab‐made carbazole is totally unobserved, strongly confirming the dramatic impact of impurity. A defect trapping mechanism in multicomponent system rather than heavy atom effect is proposed for highly efficient ULRTP after carefully analyzing the crystal packings and molecular energy levels. Inspired by this discovery, a series of effective ULRTP bi‐component systems with the highest phosphorescence efficiency of 64.1% are reproduced by directed host‐guest doping. This strategy paves a viable path for the design of organic materials with highly efficient ULRTP. [ABSTRACT FROM AUTHOR]

Sb3+ doping strategy has proved to be an effective way to regulate the band gap and improve the photophysical properties of metal halides. Herein, Sb3+‐doped lead‐free indium halide hybrid InCl6(C4H12N2)2Cl·H2O:xSb3+ (0 ≤ x ≤ 1) is reported. Upon Sb3+‐doping, the weak emission of InCl6(C4H12N2)2Cl experiences a significant enhancement in emission intensity with near‐unity photoluminescence quantum yield (PLQY). The photophysical data fitted by the power‐law equation verifies self‐trapped exciton emission for the broadband emission. Interestingly, the emission experiences a gradual red‐shift with emission color changing from green to yellow and finally to orange as the Sb3+‐doped concentration increases. The single crystal X‐ray diffraction, excitation wavelengths‐dependent emission spectra, and the distortion degree calculation of InCl6(C4H12N2)2Cl·H2O:xSb3+ (0 ≤ x ≤ 1) indicate that the Sb3+ concentration dependent luminescence results from the synergistic effect of crystal phase transition, change of luminescence center, and the distortion of crystal structure. This achievement represents a successful strategy to achieve the photophysical properties modulation of metal halides for versatile optical applications. [ABSTRACT FROM AUTHOR]

The emerging lead halide perovskites show great potential for their use as emitters in electrically driven light-emitting diodes (LEDs) with external quantum efficiency (EQE) over 25%. While the toxicity of lead and inferior device stability are the main obstacles for their commercialization, replacing Pb2+ with low- or non-toxic metal ions to form low- or zero-dimensional structures provides an alternative approach to effectively tackle these issues. Recently, luminescent lead-free metal halides have been increasingly developed toward eco-friendly and highly efficient electroluminescence. In this feature article, we give a brief overview of recent advances in luminescent lead-free metal halides and their applications in electrically driven LEDs. The challenges and prospects in this field are outlined at the end. [ABSTRACT FROM AUTHOR]

A highly sensitive and specific acetic acid probe is desirable to distinguish acetic acid from other fatty acids. Herein, we designed and synthesized two zinc complexes, H2tBuCarPyZn2Br4(AcO)2·AcOH (1) and H2tBuCarPyZn2Br4(AcO)2 (2). Both complexes exhibit fluorescence with emission peaks at 500 nm for complex 1 and 550 nm for complex 2, respectively. The DFT calculation shows that the transition from Br to the H2tBuCarPy ligand is mainly responsible for the yellow emission of complex 2, while for complex 1 the valence band consists of Br and acetic acid solvent, and the participation of acetic acid in complex 1 could result in the blue-shift of emission compared with that of complex 2. Interestingly, an obvious blue-shift of emission was observed when complex 2 was exposed to an acetic acid atmosphere. Besides, the as-exposed complex 2 could recover to the initial state once the acetic acid atmosphere was removed. PXRD results demonstrate that the phase change from complex 2 to complex 1 after absorbing the acetic acid vapor accounts for the vapor-chromism. Then complex 2 was developed as an acetic acid probe, exhibiting high sensitivity and selectivity and excellent fatigue resistance. [ABSTRACT FROM AUTHOR]

It is desirable to develop semiconductors with simultaneously multiple responses to single stimuli. Herein, a thermally responsive hybrid semiconductor (AEV)[Pb2Br8] (AEV4+ = 1,1′‐bis(2‐ammonioethyl)‐[4,4′‐ bipyridine]‐1,1′‐diium) is successfully prepared by introducing functionalized organic cations into 1D lead(II) chains. The lead(II) chain contains an edge‐sharing PbBr6 octahedron with highly electron‐deficient cations distributed in the interspace of the inorganic framework. Interestingly, the as‐formed hybrid exhibits extraordinary thermochromic behavior along with intriguing temperature‐dependent conductivity and thermal conductivity due to the thermal motion of the electrons in the hybrid. Specifically, the color of the pristine hybrid changes from yellow to brown when the temperature rises to 70 °C, and gradually deepens as the temperature continues to rise, accompanied by the continuous decline in electric conductivity and thermal conductivity. Once heating is stopped, the color and conductivity recover to the original state in a few minutes. As demonstrated by electron paramagnetic resonance and X‐ray photoelectron spectroscopy studies, the thermal‐induced electron transfer is likely responsible for the intriguing thermally responsive behaviors. This work provides a paradigm for the modular and functional design of hybrid materials that manifest potential applications in semiconductor refrigeration, thermal power generation, intelligent circuit, and other opt‐electronic devices. [ABSTRACT FROM AUTHOR]

Circular polarized luminescence (CPL)‐active materials attract great attentions owing to their widely applications in 3D optical displays and encrypted transmission. Inspired by the strategies adopted in perovskite based CPL materials, herein, CPL‐active hybrids (D)‐ and (L)‐(tert‐butyl prolinate)MnCl3 were successfully prepared by assembling chiral D/L tert‐butyl prolinate with manganese (II) chloride. Single crystal structures show the as‐formed hybrids possess one‐dimensional (1D) structure containing linear chains of face‐sharing MnCl6 octahedral surrounded by prolinate cations. The 1D Mn(II) hybrids display strong red emission peaked at 646 nm with PLQY of 67.1 % and 57.2 % for d‐type and l‐type, respectively, representing the highest PLQY for 1D MnII hybrids. Interestingly, the 1D Mn(II) hybrids exhibit prominent circular dichroism (CD) signals and remarkable CPL activity with the dissymmetry factor g of 6.1*10−3 and −6.3*10−3 from 550 to 800 nm for (D)‐ and (L)‐(tert‐butyl prolinate)MnCl3, respectively, owing to the existence of chiral cations. It is worthy noted the obtained g represents the highest value for non‐lead organic–inorganic hybrids. [ABSTRACT FROM AUTHOR]

Chiral materials with circularly polarized luminescence (CPL) are currently attracting great attention for their wide applications in bioresponsive imaging, 3D displays, and storage of information. Herein, CPL‐active enantiomorphic hybrids (R)‐ and (S)‐C6H15Cl2NO⋅SbCl5 are obtained by self‐assembling chiral R/S‐(3‐chloro‐2‐hydroxypropyl)trimethylammonium chloride with antimony(III) chloride, giving a 0D structure with SbCl5 pyramids isolated by (3‐chloro‐2‐hydroxypropyl)trimethylammonium chloride cations. The formed enantiomers exhibit brilliant orange emission peaked at 604 nm with photoluminescence quantum yield as high as 71.2%, originating from the self‐trapped exciton emission demonstrated by photophysical characterization. Due to the existence of chiral organic cations, the enantiomers exhibit strong chiral‐optical properties with mirror‐image circular dichroism signals in ground state and obvious CPL activity with the dissymmetry factor glum of 2.5 × 10−4 and −1.6 × 10−4 for R‐type and S‐type, respectively. It should be mentioned that these are the first reported 0D hybrids with CPL‐activity. This work paves an avenue for developing eco‐friendly CPL materials with highly ‐efficient luminescence. [ABSTRACT FROM AUTHOR]

As low‐dimensional lead‐free hybrids with higher stability and lower toxicity than those of three‐dimensional lead perovskites, organic antimony(III) halides show great application potential in opt‐electronic field owing to diverse topologies along with exceptional optical properties. We report herein an antimony(III) hybrid (MePPh3)2SbCl5 with a zero‐dimensional (0D) structure, which exhibits brilliant orange emission peaked at 593 nm with near‐unity photoluminescent quantum yield (99.4 %). The characterization of photophysical properties demonstrates that the broadband emission with a microsecond lifetime (3.24 μs) arises from self‐trapped emission (STE). Electrically driven organic light‐emitting diodes (OLEDs) based on neat and doped films of (MePPh3)2SbCl5 were fabricated. The doped devices show significant improvement in comparison to non‐doped OLEDs. Owing to the much improved surface morphology and balanced carrier transport in light‐emitting layers of doped devices, the peak luminance, current efficiency (CE) and external quantum efficiency (EQE) are boosted from 82 cd m−2 to 3500 cd m−2, 1.1 cd A−1 to 6.8 cd A−1, and 0.7 % to 3.1 % relative to non‐doped devices, respectively. [ABSTRACT FROM AUTHOR]

Organic metal halide hybrids (OMHHs) have attracted great research attention owing to their exceptional structure and property tunability. Using appropriate organic and inorganic metal halide components, OMHHs with controlled dimensionalities at the molecular level, from 3D to 2D, 1D, and 0D structures, can be obtained. In 0D OMHHs, anionic metal halide polyhedrons are surrounded and completely isolated by organic cations to form single crystalline "host–guest" structures. These ionically bonded organic–inorganic hybrid systems often exhibit the intrinsic properties of individual metal halide species, for instance, highly efficient Stokes‐shifted broadband emissions. In this progress report, the recent advances in the development and study of luminescent 0D OMHHs are discussed: from synthetic structural control to fundamental understanding of the structure–property relationship and device integration. [ABSTRACT FROM AUTHOR]

High color purity with narrow-band emission is a key factor for full-color displays. However, phosphorescent metal complexes typically exhibit broad emission with a full width at half maxima (FWHM) in the range of 80–100 nm. Here, we demonstrate a facile approach to achieve narrow-band emission by introducing electron-deficient moieties with electron-transport character into PtAg2 heteronuclear complexes. The as-synthesized PtAg2 complex 3 with dibenzo[b,d]thiophene 5,5-dioxide-3-acetylide shows extremely narrow emission with an FWHM of 25 nm in CH2Cl2 solution. The narrow-band emission is further verified by another two PtAg2 complexes containing electron-transport units such as oxadiazole (complex 4) and triphenyl-triazine (complex 5), in which the FWHM values are 26 nm for 4 and 28 nm for 5 in CH2Cl2 solution. TD-DFT studies suggest that the involvement of intra-ligand transition within an electron-deficient acetylide ligand is likely responsible for the narrow-band emission. Solution-processed OLEDs based on complex 4 exhibit excellent device performance with an FWHM of 37 nm in the electroluminescent spectrum and the highest current efficiency (CE) of 69.5 cd A−1, power efficiency (PE) of 50.5 lm W−1 and external quantum efficiency (EQE) of 18.2%. The narrow-band electroluminescence is also attained in complexes 3 and 5 with the FWHM values of 31 and 40 nm, respectively, which represent the narrowest electroluminescence for multinuclear metal complexes. This strategy of introducing electron-transport moieties not only improves the device performance but also narrows the emission width and thus enhances the color purity. [ABSTRACT FROM AUTHOR]

The photophysical tuning is reported for a series of tetraphenylphosphonium (TPP) metal halide hybrids containing distinct metal halides, TPP2MXn (MXn=SbCl5, MnCl4, ZnCl4, ZnCl2Br2, ZnBr4), from efficient phosphorescence to ultralong afterglow. The afterglow properties of TPP+ cations could be suspended for the hybrids containing low band gap emissive metal halide species, such as SbCl52− and MnCl42−, but significantly enhanced for the hybrids containing wide band gap non‐emissive ZnCl42−. Structural and photophysical studies reveal that the enhanced afterglow is attributed to stronger π–π stacking and intermolecular electronic coupling between TPP+ cations in TPP2ZnCl4 than in the pristine organic ionic compound TPPCl. Moreover, the afterglow in TPP2ZnX4 can be tuned by controlling the halide composition, with the change from Cl to Br resulting in a shorter afterglow due to the heavy atom effect. [ABSTRACT FROM AUTHOR]

Zero‐dimensional (0D) organic metal halide hybrids, in which organic and metal halide ions cocrystallize to form neutral species, are a promising platform for the development of multifunctional crystalline materials. Herein we report the design, synthesis, and characterization of a ternary 0D organic metal halide hybrid, (HMTA)4PbMn0.69Sn0.31Br8, in which the organic cation N‐benzylhexamethylenetetrammonium (HMTA+, C13H19N4+) cocrystallizes with PbBr42−, MnBr42−, and SnBr42−. The wide band gap of the organic cation and distinct optical characteristics of the three metal bromide anions enabled the single‐crystalline "host–guest" system to exhibit emissions from multiple "guest" metal halide species simultaneously. The combination of these emissions led to near‐perfect white emission with a photoluminescence quantum efficiency of around 73 %. Owing to distinct excitations of the three metal halide species, warm‐ to cool‐white emissions could be generated by controlling the excitation wavelength. [ABSTRACT FROM AUTHOR]

Optically pumped white light-emitting diodes (WLEDs), consisting of blue/ultraviolet LED chips and down conversion phosphors, have a wide range of applications in our daily life, such as full color display and solid-state lighting. While remarkable progress in light quality, device efficiency, and lifetime has been achieved during the last two decades, many challenges remain in optically pumped WLEDs, and searching for low cost high performance down conversion phosphors is still of great interest. Recently, metal halide perovskites have emerged as a highly promising new generation of light emitters for their exceptional optical properties with high quantum efficiencies and color tunability, which have also inspired researchers to investigate their derivatives. In this perspective, we briefly review the progress during the last few years in the development of metal halide perovskites and perovskite-related materials as down conversion phosphors for optically pumped WLEDs. We also highlight some major issues and challenges that need to be addressed to enable perovskite-based light emitters to possibly replace currently used rare-earth doped inorganic phosphors and quantum dots. [ABSTRACT FROM AUTHOR]

Two new Diels–Alder type adducts, macrourins I and J ( 1–2 ), along with seven known analogues ( 3–9) were isolated from the stems of Morus macroura Miq. The structures of the two new compounds were elucidated by extensive analysis of spectroscopic data. Compounds 1–9 all showed highly potent in vitro α-glucosidase inhibitory activities, and the IC 50 values of compounds 1 and 2 were 1.70 and 1.58 μM, respectively, approximately 800 times stronger than the positive control, acarbose. [ABSTRACT FROM AUTHOR]

A novel dihydroflavonol unprecedentedly with a prenyl group at C-2, nigragenon A ( 1 ), four new sanggenon-type flavonones, nigragenons B–E ( 2 – 5 ), along with six known isoprenylated flavonoids ( 6 – 11 ) were isolated from the twigs of Morus nigra . Their structures were elucidated through extensive analysis of spectroscopic data. Interestingly, compound 1 was the first reported biogenetic precursor of sanggenon-type flavanones and the biogenetic pathway from 1 to sanggenol F was proposed. The PPAR γ agonistic activity was investigated in HEK293 cells using dual luciferase reporter assay. Compounds 2 , 4 , 7 , and 9 showed obvious agonistic activities on PPAR γ, and compound 2 was a potential PPAR γ partial agonist. Moreover, the preliminary structure-activity relationships for the tested compounds were discussed. [ABSTRACT FROM AUTHOR]

The syntheses and luminescent properties of two new visible light excitable lanthanide complexes (NBu4[LnL4]) [L = 1-(4-(9H-carbazol-9-yl)phenyl)-4,4,4-trifluorobutane-1,3-dione; (Ln = Sm3+, Eu3+)] are described. The (NBu4[LnL4]) complexes exhibit bright photoluminescence at room temperature in solid state with characteristic red and orange emissions of Eu3+ and Sm3+ ions, respectively. Photoluminescent overall quantum yield (Φov) and lifetime (τobs) values obtained for the complexes are 80 ± 8%, 780 ± 6 μs for (NBu4[EuL4]) and 10% ± 1%, 97 ± 2 μs for (NBu4[SmL4]) (λex = 410 nm) in solid state. RM1 calculations were employed for predicting the ground-state geometry of NBu4[EuL4], which shows that the central Eu3+ is 8-fold coordinated. Theoretical Judd–Ofelt and photoluminescence parameters predicted for NBu4[EuL4] from this model are in close agreement with the experimental values, proving the efficiency of this theoretical approach implemented in the LUMPAC software (URL URL="HTTP://LUMPAC.PRO.BR/THEORY"http://lumpac.pro.br/theory/URL). LEDs with the general structure ITO/PEDOT:PSS (50 nm)/(NBu4[LnL4]) (5%):CBP (66.5%)–OXD7 (28.5%) (50 nm)/BCP (50 nm)/LiF (1.5 nm)/Al (120 nm), using the two complexes as emitters were fabricated via a simple spin coating technique. The device based on (NBu4[EuL4]) exhibits the maximum brightness of 1234 cd m−2, current efficiency of 3.5 cd A−1, power efficiency of 1.3 lm W−1 and external quantum efficiency of 2.3% with a pure red emission. Whereas, its Sm3+ analogue shows bright orange emission with a maximum brightness of 831 cd m−2, current efficiency of 1.4 cd A−1, power efficiency of 0.5 lm W−1, and external quantum efficiency of 1.1%. [ABSTRACT FROM AUTHOR]

Cationic PtAu2 heterotrinuclear complexes [PtAu2(dpmp)2(C≡CR)2]2+ (dpmp = bis(diphenylphosphinomethyl)phenylphosphine, R = aryl) of aromatic acetylides were prepared. The PtAu2 structures are supported through doubly bridging dpmp and stabilized by a significant Pt–Au interaction. They are highly phosphorescent in fluid CH2Cl2 solution (Φem = 23.5%–78.9%), the solid state (Φem = 15.4%–70.2%), the PMMA film (Φem = 39.9%–71.7%) and the doping film of 61% TCTA : 31% OXD-7 : 8% PtAu2 complex (Φem = 16.9%–67.9%). The phosphorescence arises mainly from 3[π (C≡CR) →π* (dpmp)] 3LLCT and 3[π (C≡CR) → s/p (PtAu2)] 3LMCT triplet excited states for carbazole-acetylide complexes, whereas other complexes display a 3LLCT character mixed with noticeable PtAu2 centered 3[d → s/p] parentage. Utilizing a mixed host composed of hole-transporting TCTA and electron-transporting OXD-7 doped with 8% PtAu2 species as a light-emitting layer and CuSCN as a hole-transporting layer through an orthogonal solution process, the devices exhibit highly efficient electrophosphorescence with the highest current efficiency (CEmax) of 51.7 cd A−1 and external quantum efficiency (EQEmax) of 14.5%. The efficiency roll-off is small in the practical brightness range of 500–5000 cd m−2. The PtAu2 complexes with carbazole-acetylides display a higher electroluminescence efficiency ascribed to their better hole-transporting character as well as more facile energy transfer from mixed host materials. [ABSTRACT FROM AUTHOR]

Two triphosphine-participated PtAu2 heterotrinuclear complexes with phenothiazine functionalized acetylides were prepared. The crystal structural determination indicates that because of a short Pt–Au distance of 2.9549(4) Å, the PtAu2 heterotrinuclear array supported by double triphosphine ligands exhibits substantial Pt–Au intermetallic contact. The PtAu2 complexes show moderate phosphorescent emission in fluid solution and the powder state, but intense orange and yellow phosphorescence in doped poly(methyl methacrylate) films with quantum yields of 73.7% and 48.9%, respectively. The phosphorescence arises from an admixture of 3[π(phenothiazine–acetylide) →π*(triphosphine)] 3LLCT and 3[π(phenothiazine–acetylide) → p/s(PtAu2)] 3LMCT triplet excited states. Utilizing blended host materials composed of both hole-transport TAPC and electron-transport OXD-7 doping with 8% phosphorescent PtAu2 complex as emitting layer, solution-processed organic light-emitting diodes (OLEDs) gave orange electroluminescence with the highest current efficiency of 35.4 cd A−1 and external quantum efficiency of 18.7%. [ABSTRACT FROM AUTHOR]

A series of new dinuclear copper complexes with a tetraphosphane bridging ligand, [{(pz4B)Cu}2(µ-tpbz)] ( 1), [{(pz2BH2)Cu}2(µ-tpbz)] ( 2), and [{(tz2BH2)Cu}2(µ-tpbz)] ( 3) [tpbz = 1,2,4,5-tetrakis(diphenylphosphanyl)benzene, pz4B = tetrakis(pyrazol-1-yl)borate, pz2BH2 = bis(pyrazol-1-yl)borohydrate, and tz2BH2 = bis(1,2,4-triazol-1-yl)borohydrate], have been synthesized and structurally characterized. The CuI atoms in these complexes are four-coordinate and adopt a tetrahedral coordination geometry. In each complex, the copper centers are bridged by a tpbz ligand and each CuI is further terminally chelated by a borate diimine anion. The central phenylene ring and the phosphine atoms of the tpbz ligand are essentially planar. The two CuI atoms in each molecule are located above and below the (P2C6H2P2) mean plane, respectively, leading to a chair-like conformation for the [Cu](P2C6H2P2)[Cu] fragment. The distances between the CuI atoms in each complex are about 8.7 Å. In the solid state, these complexes are emissive and exhibit yellow-orange photoluminescence [emission peaks, λmax = 580 nm ( 1), 569 nm ( 2), 540 nm ( 3)] with lifetimes of 7.4-20.5 µs and quantum yields Φ = 0.07-0.45 at room temperature. Theoretical and experimental results indicate that these complexes have the lowest singlet (S1) state and the lowest triplet (T1) state with very close energy levels, and display thermally activated delayed fluorescence (TADF) at ambient temperature. [ABSTRACT FROM AUTHOR]

We report, herein, the use of phosphorescent copper(i)–silver(i) heterometallic complexes to achieve highly efficient electroluminescence. The trigonal prism arranged Ag6Cu heteroheptanuclear alkynyl cluster complexes show intense phosphorescence in a fluid solution, powder and thin film with quantum yields as high as 0.78. Complex 1 with 1-(tert-butyl)-4-ethynylbenzene (HC≡CC6H4But-4) shows reversible phosphorescence vaporchromism in respose to THF or CHCl3. The phosphorescent emission exhibits an obvious blue-shift from 580 nm to 530 nm for THF and to 538 nm for CHCl3 with a remarkable luminescence change from bright yellow to green. As demonstrated experimentally and theoretically, the phosphorescence originates from 3[π(aromatic acetylide) → s/p(Ag6Cu)]3LMCT and Ag6Cu cluster centered 3[d → s/p] triplet states. Taking advantage of the doped light-emitting layer of 57% TCTA:28% OXD-7:15% Ag6Cu complex with hole-transporting TCTA and electron-transporting OXD-7 as a blended host, solution-processed OLEDs gave highly efficient electroluminescence with a current efficiency (CE) of 42.5 cd A−1 and external quantum efficiency (EQE) of 13.9% at low voltage (4.5 V) with a practical brightness of 184 cd m−2. [ABSTRACT FROM AUTHOR]

Color tunable electroluminescence is obtained from devices having a spin-coated single emitting layer with a novel EuIII-tetrakis-β-diketonate complex NBu4[EuL4] (L− = 4-(4′-carbazol-9-yl-biphenyl-4-yl)-1,1,1-trifluoro-4-oxo-but-2-en-2-ol anion) doped with CBP (4,4′-N,N′-dicarbazolebiphenyl)–OXD7 (1,3-bis[2-(4-tert-butylphenyl)-1,3,4-oxadiazo-5-yl]benzene) blend. An external quantum efficiency (EQE) as high as 2.8%, maximum brightness (L) of 1547 cd m−2, current efficiency (ηc) of 5.14 cd A−1 and power efficiency (ηp) of 2.53 lm W−1 were shown by a device having the structure ITO/PEDOT:PSS (50 nm)/CBP (56%):OXD7 (24%):NBu4[EuL4] (20%) (50 nm)/TPBI (50 nm)/LiF (1.5 nm)/Al (120 nm). The newly designed β-diketonate ligand containing hole-transporting carbazole group and π-spacer extends the excitation window of the EuIII-complex to 450 nm and also improves the carrier transport properties. The modification in the ligands results in a low turn-on voltage of the devices (＜5 V). Furthermore, the devices containing 10–20% NBu4[EuL4] in the emitting layers show white emission in a wide voltage range (8–13 V) with sizable efficiencies. [ABSTRACT FROM AUTHOR]

Cationic Au4Ag2 heterohexanuclear aromatic acetylides cluster complexes supported by bis(2-diphenylphosphinoethyl)phenylphosphine (dpep) are prepared. The Au4Ag2 cluster structure originating from the combination of one anionic [Au(C≡CR)2]− with one cationic [Au3Ag2(dpep)2(C≡CR)2]3+ through the formation of Ag−acetylide η2-bonds is highly stabilized by Au-Ag and Au-Au contacts. The Au4Ag2 alkynyl cluster complexes are moderately phosphorescent in the fluid CH2Cl2 solution, but exhibit highly intense phosphorescent emission in solid state and film. As revealed by theoretical computational studies, the phosphorescence is ascribable to significant 3[π (aromatic acetylide) → s/p (Au)] 3LMCT parentage with a noticeable Au4Ag2 cluster centered 3[d → s/p] triplet state. Taking advantage of mCP and OXD-7 as a mixed host with 20 wt% dopant of phosphorescent Au4Ag2 cluster complex in the emitting layer, solution-processed organic light-emitting diodes (OLEDs) exhibit highly efficient electrophosphorescence with the maximum current, power, and external quantum efficiencies of 24.1 cd A−1, 11.6 lm W−1, and 7.0%, respectively. Introducing copper(I) thiocyanate (CuSCN) as a hole-transporting layer onto the PEDOT:PSS hole-injecting layer through the orthogonal solution process induces an obvious improvement of the device performance with lower turn-on voltage and higher electroluminescent efficiency. [ABSTRACT FROM AUTHOR]

The synthesis, structure, and phosphorescence properties of twofamilies of triphosphine-supported Au(I)–Ag(I) heteronuclearalkynyl cluster complexes with unprecedented Au2Ag2and Au8Ag4cluster structures are described.The phosphorescence emission over the whole visible light region wassystematically tuned through modification of the electronic effectsin aromatic acetylide ligands to attain bright phosphorescence withdifferent luminescent colors. Introduction of electron-withdrawingCF3to phenylacetylides results in the emission spectralblue-shift, while it shows progressive red-shift upon introducingelectron-donating But, OMe, or NMe2. As demonstratedfrom both experimental and theoretical studies, the phosphorescencearises primarily from 3LLCT/3IL and Au2Ag2/Au8Ag4cluster-centered 3[d→p] transitions. [ABSTRACT FROM AUTHOR]