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In this work, four monomers, M1, M2, M3, and M4, were designed and synthesized. M1 + M2 + M3 + M4 + Zn(OTf)2 could self-assemble into a sequence-controlled supramolecular copolymer through self-sorting at relatively high concentrations. The self-sorting assembly of the four monomers was verified by NMR spectroscopy, UV-Vis spectroscopy, viscosity measurements, dynamic light scattering, fluorescence spectroscopy, SEM, and TEM analyses. The experimental results showed that supramolecular polymerization depended on the initial concentrations of the monomers. The resulting supramolecular copolymer (SCP) showed K+ responsiveness, and adding-removing K+ could drive the disassembly-reassembly of SCP. Moreover, OH− could enhance the fluorescence emission of the SCP-based solution or film. The SCP could also be applied to prepare honeycomb-patterned films. With stimuli-responsive behavior and regulatable fluorescence properties, the SCP has potential application value in creating smart adaptive materials.

Contamination of aircraft cabin air can result from leakage of engine oils and hydraulic fluids into bleed air. This may cause adverse health effects in cabin crews and passengers. To realistically mimic inhalation exposure to aircraft cabin bleed-air contaminants, a mini bleed-air contaminants simulator (Mini-BACS) was constructed and connected to an air-liquid interface (ALI) aerosol exposure system (AES). This unique "Mini-BACS + AES" setup provides steady conditions to perform ALI exposure of the mono- and co-culture lung models to fumes from pyrolysis of aircraft engine oils and hydraulic fluids at respectively 200 °C and 350 °C. Meanwhile, physicochemical characteristics of test atmospheres were continuously monitored during the entire ALI exposure, including chemical composition, particle number concentration (PNC) and particles size distribution (PSD). Additional off-line chemical characterization was also performed for the generated fume. We started with submerged exposure to fumes generated from 4 types of engine oil (Fume A, B, C, and D) and 2 types of hydraulic fluid (Fume E and F). Following submerged exposures, Fume E and F as well as Fume A and B exerted the highest toxicity, which were therefore further tested under ALI exposure conditions. ALI exposures reveal that these selected engine oil (0-100 mg/m3) and hydraulic fluid (0-90 mg/m3) fumes at tested dose-ranges can impair epithelial barrier functions, induce cytotoxicity, produce pro-inflammatory responses, and reduce cell viability. Hydraulic fluid fumes are more toxic than engine oil fumes on the mass concentration basis. This may be related to higher abundance of organophosphates (OPs, ≈2800 µg/m3) and smaller particle size (≈50 nm) of hydraulic fluid fumes. Our results suggest that exposure to engine oil and hydraulic fluid fumes can induce considerable lung toxicity, clearly reflecting the potential health risks of contaminated aircraft cabin air.

Rare earth (RE

Inorganic scintillation materials have been widely used in several fields, such as high energy physics, nuclear medical imaging and industrial nondestructive inspection. In this work, a novel scintillation material, (CexLu1-x)3Al5O12/Al2O3 (Ce3+:LuAG/Al2O3) eutectic with different Ce3+-doping concentrations, was successfully grown by the micropulling down method at different pulling speeds. The effects of Ce3+-doping concentration and pulling speed on the microstructure and luminescent properties of the Ce3+:LuAG/Al2O3 eutectic were investigated. The eutectic has a typical garnet structure, and a “Chinese script” microstructure can be seen throughout the cross section. As the pulling speed increased, the grain size and the morphological appearance of the “Chinese script” microstructure decreases. The Ce3+:LuAG/Al2O3 eutectic shows a characteristic Ce3+ emission band centered at 508 nm, and the emission intensity increases with increasing Ce3+-doping concentration until the Ce3+-doping concentration reaches x = 0.01. The eutectic grown at a pulling speed of 1.7 mm/min shows maximum emission intensity, and the light yield of the (Ce0.01Lu0.99)3Al5O12/Al2O3 eutectic excited with X-ray at room temperature is approximately 64% of that of the (Ce0.01Lu0.99)3Al5O12 single crystal. The results reveal that the Ce3+:LuAG/Al2O3 eutectic has a potential application as an X-ray detector material.

A novel red phosphor LiAl4O6F:Mn4+ (in brief LAOF:Mn4+) is prepared by a solid-state reaction method. X-ray diffraction (XRD), scanning electron microscope (SEM), photoluminescence excitation and emission spectra and decay curves are used to characterize the properties of LAOF:Mn4+ phosphors. Under 450 nm excitation, it is observed an intense red emission peak around 662 nm, which corresponds to 2Eg-4A2g transition of Mn4+ in LAOF:Mn4+ phosphor. The optimum molar doping concentration of Mn4+ ions in LAOF host is 0.2%. On the basis of the temperature-dependence luminescence spectra, the activation energy is about 0.32 eV for the LAOF:Mn4+ phosphor. The crystal field strength (Dq) and the Racah parameters (B and C) are carefully calculated to evaluate the nephelauxetic effect of Mn4+ in the LAOF host. The excellent luminescent properties of LAOF:Mn4+ suggest this material could be a promising deep-red phosphor for solid-state lighting.

Relatively high concentrations of ultrafine particles (UFPs) have been observed around airports, in which aviation and road traffic emissions are the major sources. This raises concerns about the potential health impacts of airport UFPs, particularly in comparison to those emitted by road traffic. UFPs mainly derived from aviation or road traffic emissions were collected from a location near a major international airport, Amsterdam-Schiphol airport (AMS), depending on the wind direction, along with UFPs from an aircraft turbine engine at low and full thrust. Human bronchial epithelial cells (Calu-3) model in combination with an air-liquid interface (ALI) cloud system was used for the in vitro exposure to UFPs at low doses ranging from 0.09 to 2.07 μg/cm2. Particle size distribution was measured. Cell viability, cytotoxicity and inflammatory potential (interleukin (IL) 6 and 8 secretion) on Calu-3 cells were assessed after exposure for 24 h. The biological measurements on Calu-3 cells confirm that pro-inflammatory responses still can be activated at the high cell viability (> 80%) and low cytotoxicity. By the Benchmark Dose (BMD) analysis, Airport and Non-Airport (road traffic) UFPs as well as UFPs samples from a turbine engine have similar toxic properties. Our results suggest that UFPs from aviation and road traffic in airport surroundings may have similar adverse effects on public health.

A new far-red/green dual-emitting phosphor La2ZnTiO6:Mn4+/Er3+ (LZT:Mn4+/Er3+) was successfully synthesized by the sol-gel method. Under 381 ​nm excitation, LZT:Mn4+/Er3+ phosphor shows the strong far-red emission peak of 709 ​nm (Mn4+: 2Eg→4A2g) and weak green emission peak of 523/548 ​nm (Er3+: 2H11/2/4S3/2 ​→ ​4I15/2), which consistent with the requirement of plant growth for far-red and green light. A 1.5-fold enhancement of far-red emission intensity is found in LZT:Mn4+/Er3+ phosphor compared with the Mn4+ singly-doped counterparts. Moreover, the relative emission intensity of far-red and green can be easily controlled by changing temperature. Utilizing the optimal LZT:0.2%Mn4+/2%Er3+ phosphor as plant lighting, a prototype near-UV-pumped LED device was fabricated. Upon 120 ​mA driving current, it demonstrated far-red/green dual emission. All the results indicated that the LZT:Mn4+/Er3+ phosphor is a potential material for plant growth illumination with far-red/green light.

A variety of diketopyrrolopyrrole (DPP)-based linear or branched π-conjugated oligomers, with a core of phenyl, phenyl-DPP, tetraphenylethene, pyrene and spirobifluorene, containing sequentially bis-, tris-, and tetra-DPP with various geometries and molecular weights of several thousands has been effectively accessed by one-step C–H activated coupling followed by a single column chromatographic separation. A further optical property study of all eight synthesized oligomers reveals the correlation between light absorption and the variation of geometries and π-conjugation lengths. This atom- and step-economical, and versatile synthetic strategy will be a powerful tool for accessing π-functional large oligomers, which enriches the library of π-materials and thus facilitates the fundamental structure–property study.

Metallo-organic molecules showing reversible structural phase transitions accompanied with ferroelectric and dielectric properties have seldom been reported. By making use of the “driving/controlling force” from the rotating motion of cyclopentadienyl rings for a reversible structural transition and then carrying out structural modifications on their local parts to create remnant polarization through this molecular system, we designed and constructed a new ferroelectric, which is the adduct of hexamethylenetetramine ferrocene carboxylic acid, (C6H12N4)[Fe(C5H5)(C6H5O2)] (1). Compound 1 undergoes a reversible structural phase transition at around 187 K, which is confirmed by remarkable dielectric and heat anomalies. The synergistic interactions of the twisting motions of the adduct molecules and the inner cyclopentadienyl rings lead to the reversible phase transition. A dipole moment from amine group to carboxylic acid at low temperature produces a net spontaneous polarization, which results in the ferroelectricity of 1-LTP. On further investigation, it is observed that compound 1 has a perfect ferroelectric hysteresis loop with a spontaneous polarization of 3.95 μC cm−2.

Diketopyrrolopyrrole (DPP) is an important type of &pi, conjugated building block for high-performance organic electronic materials. DPP-based conjugated materials are usually synthesized via Suzuki, Stille, or Negishi cross-coupling reactions, which require organometallic precursors. In this paper, a series of novel phenyl-cored DPP molecules, including five meta-phenyl-cored molecules and four para-phenyl-cored molecules, have been synthesized in moderate to good yields, in a facile manner, through the Pd-catalyzed direct arylation of C&ndash, H bonds, and their optoelectrical properties have been investigated in detail. All new molecules have been fully characterized by NMR, MALDI-TOF MS, elemental analysis, UV&ndash, visible spectroscopy, and cyclic voltammetry. This synthetic strategy has evident advantages of atom- and step-economy and low cost, compared with traditional cross-coupling reactions.

NaGd(WO4)2:Yb3+/Er3+ (NGW:Yb3+/Er3+) phosphors co-doped with Yb3+ (12–24 at%, at% i.e. atomic percent) and Er3+ ions (1–10 at%) were synthesized by a facile hydrothermal process. Under 980 nm excitation, NGW:Yb3+/Er3+ phosphors exhibited strong green upconversion (UC) emission bands centered at 532 nm (2H11/2 → 4I15/2) and 554 nm (4S3/2 → 4I15/2) and weak red emissions near 658 and 671 nm (4F9/2 → 4I15/2). The optimum doping concentrations of Er3+ and Yb3+ for the highest emission intensity were determined by using X-ray diffraction (XRD) and photoluminescence (PL) analyses. Concentration dependent studies revealed that the optimal composition was realized for the 20 at% Yb3+ and 6.0 at% Er3+-doping concentration with a strong green emission. A possible UC mechanism for NGW:Yb3+/Er3+ depends on the pump power is discussed. The temperature dependence of the fluorescence intensity ratios (FIR) for the two green UC emission bands peaking at 532 and 554 nm was studied in the range of 293–573 K under excitation by a 980 diode laser and the maximum sensitivity was approximately 114.96 × 10−4 K−1 at 453 K. This indicates that NGW:Yb3+/Er3+ phosphors are potential candidates for optical temperature sensors with high sensitivity.

Hydrothermal reaction of CuSO4·7H2O and NaN3 with 2-cyanothiophene in aqueous ethanol yielded a novel tetranuclear copper(I) polymer, {[Cu4(tptz)4]·0.5(C2H6O)}n (1) (Htptz = 5-(thiophen-2-yl)-1H-tetrazole). The tptz ligand in the complex was generated through an in situ [2 + 3] cycloaddition reaction involving the cyano groups of the precursor 2-cyanothiophene. In a rare example, three different geometries of Cu(I) cations, namely the linear, triangle, and tetrahedron geometries of Cu(I) centers, are created and linked by Htptz ligands into a 1-D ladder structure. Additionally, 1 exhibits strong blue fluorescence (with λ = 467 nm) at room temperature in the solid state.

Hydro(solvo)thermal reactions between a new flexible multicarboxylate ligand, 2,2′-azanediyldibenzoic acid (H2L), and M(OH)2 (M = Cd, Zn) in the presence of different N-donor ancillary ligands, 4,4′-bipyridine (bpy) and pyridine (py), afford three novel coordination polymers: [Cd2(L)2(bpy)1.5(H2O)]n (1), [Cd2(L)(Py)2]n (2), and [Zn2(L)2]n (3). These polymers show great differences in regard to their structures and properties due to the variation in the ancillary ligands and in the coordination geometry of the metal ions. Compound 1 exhibits a 3D supramolecular network assembled from 2D layered architecture composed of dinucelar cadmium subunits via intermolecular π⋯π and C–H⋯π interactions. The supramolecular structure of compound 2 is built from the packing of two homochiral helical chain. Compound 3 possesses two crystallographically nonequivalent metal atoms with Zn1 in a four-coordinated tetrahedron geometry and Zn2 in a five-coordinated trigonal bipyramid geometry. Five different coordination modes, ranging from μ2, μ3 and μ4, have been observed in the H2L ligands. The solid-state fluorescence spectra show that complexes 1 and 2 exhibit small shifts to the blue, while 3 is red shifted with respect to the free ligand.

A new family of homochiral lanthanide dinuclear complexes based on a chiral carboxylate, namely [Ln(R-pba)(3)(phen)](2) (Ln = La (1), Ce (2), Pr (3), Nd (4), Sm (5), Eu (6), Gd (7), Tb (8), Dy (9) and Ho (10), R-pba = (R)-2-phenylbutyric acid, phen = 1,10-phenanthroline), have been synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analyses and IR spectra. Complexes 1-10 are isostructural and crystallize in the chiral space group P2(1). Their optical activity and enantiomeric nature were confirmed by the circular dichroism spectra. Complexes 6, 8 and 9 exhibit strong fluorescent emissions with typical narrow emission bands of lanthanide ions and 6 and 8 display relatively high quantum yields. Magnetic investigations revealed that the weak antiferromagnetic exchange and/or the depopulation of the Ln(III) excited Stark sub-levels which exist in 7-10.

Pyrochlore Y2Sn2O7 nanophosphors codoped with Er3+ (fixed 2 at.%) and Yb3+ ions (2–16 at.%) were synthesized via hydrothermal process followed by heat treatment. We investigate the infrared-to-visible upconversion (UC) luminescence properties of Er–Yb codoped Y2Sn2O7. Upon 980 nm excitation at room temperature, green (at ~522 and 544 nm) and red (at ~661 nm) UC emissions were observed, which are ascribed to the (2H11/2, 4S3/2) → 4I15/2 and 4F9/2 → 4I15/2 transitions, respectively. It has been found that the Yb3+-doping concentrations have greatly influenced on the UC luminescence intensity and the emission ratio of the red and green in Y2Sn2O7:Yb3+/Er3+ nanophosphors. The tunable emission is due to the energy back transfer from Er3+ to Yb3+ and the cross relaxation between the two neighboring Er3+ ions. It is expected that the achieved single and intense red emission band may have potential application for in vivo bioimaging.

Air traffic is rapidly growing, raising concerns about the air pollution in the surroundings of airports and its impact on public health. However, little is known about the impact of air pollution sources on air quality and health in the vicinity of airports. In this study, the sources and adverse health effects of airport-related particulate matter (PM) were investigated and compared to those of urban traffic emissions. Ambient PM0.25 were collected at the Los Angeles International Airport (LAX) and at a central Los Angeles site (USC campus), along with PM2.5 collected directly from turbine and diesel engines. The particle chemical composition, oxidative potential (OP) (ascorbic acid (AA), and electron spin resonance (ESR) assay) as well as their reactive oxygen species (ROS) activity, inflammatory potential (interleukin (IL) 6 and 8 and tumor necrosis factor (TNF)-α) and cytotoxicity on human bronchial epithelial (16HBE) cells were assessed. Chemical composition measurements confirmed that aircraft emissions were the major source to LAX PM0.25, while the sources of the USC samples were more complex, including traffic emissions, suspended road and soil dust, and secondary aerosols. The traffic-related transition metals (Fe and Cu) in LAX and USC samples mainly affected OP values of particles, while multiple factors such as composition, size distribution and internalized amount of particles contributed to the promotion of ROS generation in 16HBE cells during 4 h exposure. Internalized particles in cells might also play an important role in activating inflammatory responses during cell recovery period, with LAX particles being more potent. Our results demonstrated considerable toxicity of airport-related particles, even at low exposure concentrations, suggesting that airport emission as source of PM0.25 may also contribute to the adverse effects on public health attributable to PM. The potency of such particles is in the same range as those collected at a site in urban area impacted heavily by traffic emissions.

Moreover, in most of reported copper tetra-zole complexes, the central copper atoms often adopt eitherfour or five or six coordination modes, three coordinationmodes of copper complexes have not been reported before.Fortunately, when we perform pure inorganic complex bis-(4-cyanopyrdine)copper(II) azide replacing the organic cyanogroup and NaN

Monodispersed spheres (1–4 μm in diameter) of BaWO4:Eu3+ (hereafter BWO:Eu) red-phosphor exhibiting intense emission at 615 nm were synthesized via a mild hydrothermal method. X-ray diffraction, scanning electron microscope, photoluminescence excitation and emission spectra, and decay curve were used to characterize the properties of BWO:Eu phosphors. An intense red emission was obtained by exciting either into the 5L6 state with 394 nm or the 5D2 state with 465 nm, that correspond to two popular emission lines from near-UV and blue LED chips, respectively. The values of Ω 2,4 experimental intensity parameters (13.8 × 10−20 and 8.2 × 10−20 cm2) are determined. The high-emission quantum efficiency of the BWO:Eu phosphor suggests this material could be promising red phosphors for generating white light in phosphor-converted white light-emitting diodes.

AWO 4 :Tm 3+ (A = Ca, Sr and Ba) blue phosphors were prepared via a mild and facile hydrothermal route. X-ray diffraction (XRD), scanning electron microscope (SEM), photoluminescence excitation and emission spectra and decay curve were used to characterize the AWO 4 :Tm 3+ phosphors. By analyzing the excitation and emission spectra of AWO 4 :Tm and undoped AWO 4 samples, the result indicates that there exists the energy transfer from the WO 4 2− group to the Tm 3+ ion only in CaWO 4 :Tm phosphor. The luminescence decay curves from the 1 D 2 state of Tm 3+ in AWO 4 phosphors show bi-exponential characteristics when excited directly to the 1 D 2 state, implying that there exist two luminescence centers in AWO 4 :Tm phosphors. Because AWO 4 :Tm 3+ phosphors exhibit intensive blue emission and high color purity under UV excitation, it is considered to be a new promising blue phosphor for field emission display application.

Both title compounds, {[Ag2(C10H8N2)2](C6H5O6PS)·3H2O}n, (I), and {[Co(C10H8N2)2(H2O)4](C6H5O6PS)}n, (II), respectively, contain similar novel symmetric dimeric [O3S–C6H4–PO3H]2− anions formed via two shared (O⋯H⋯O) H atoms on twofold positions between two –PO3H− groups. The two-coordinate AgI structure features one-dimensional polymeric chains of {[Ag(4,4′-bipy)]22+}n (4,4′-bipy is 4,4′-bipyridine), weakly linked by π–π inter­actions, separated by the anionic dimers which are stabilized into layers by hydrogen bonding to three water mol­ecules. In (II), a twofold crystallographic axis runs through the one-dimensional {[Co(4,4′-bipy)(H2O)4]2+}n chains containing six-coordinate CoII; three-dimensional packing is provided by hydrogen bonding using all sulfonate and –PO3H− O atoms as acceptors and the Co-bound water H atoms as donors. In this latter case, the benzenesulfonate aromatic rings are also constrained to a mirror plane. This report illustrates how a previously unreported dianion can affect the crystallization of polymeric metal complex cations.

A new series of mononuclear copper(I) halide complexes possessing 5-tert-butyl-3-(pyrimidine-2-yl)-1H-1,2,4-triazole (bpmtzH) and PPh3, Cu(bpmtzH)(PPh3)X (X = I (1); Br (2); Cl (3)), have been synthesized and characterized. As revealed via X-ray crystallography, 1–3 show a chiral, distorted tetrahedral N2PX arrangement, in which bpmtzH is a neutral bidentate chelating ligand using the 4-N of the 1,2,4-triazolyl ring and one N donor from the 2-pyrimidyl ring, consistent with the computational results. A comparatively weak low-energy absorption tail is observed between 320 and 450 nm for CH2Cl2 solutions of 1–3 at room temperature, ascribing to charge-transfer transitions with appreciable metal-to-ligand charge transfer (MLCT) character. Complexes 1–3 in the solid state have good luminescence at ambient temperature, although they are non-emissive in solution. The solid-state emission, most likely originating from both 3MLCT and 3XLCT transitions, can be modulated via alteration of the halide bound to {Cu(bpmtzH)(PPh3)} motif.

The title polymer, [Cu(C6H5O6PS)(C10H8N2)(H2O)] n , was synthesized by a hydrothermal method. The CuII ion is five-coordinated by one phosphonate O atom, one sulfonate O atom, two N atoms of the bipyridyl ligand and one water molecule. The coordination geometry around the metal centre can be described as slightly distorted square-pyramidal. The CuII ions are connected by bidentate bridging phosphonato-benzenesulfonate ligands, forming one-dimensional helical chains along [010], which are further bridged by bidentate 4,4′-bipyridyl ligands, generating a two-dimensional layered crystal structure. The layered structure features an eight-membered ring including four CuII ions, two [O3S–C6H4–PO3H]2− anions and two 4,4′-bipyridyl ligands. Hydrogen bonds involving aqua ligands, phosphonate O and sulfonate O atoms are observed between the layers

The title complex, [Co(C12H8N2)(H2O)4](C10H6O6S2)·2H2O, was synthesized hydro­thermally. The Co2+ cation, which lies on a twofold rotation axis, is six-coordinate. The anion is located on a centre of inversion. An extensive network of O—H⋯O hydrogen bonds links the components into a three-dimensional network.

In the title compound, C6H7N3O2·H2O, all atoms of 2-ureidopyridine N-oxide mol­ecule are approximately coplanar and adjacent mol­ecules are connected by strong hydrogen bonds, resulting in a three-dimensional network.

The title complex, [Cu(C7H2N2O7)(C4H8N2O2)(H2O)], is a mononuclear copper(II) compound. The CuII ion is five-coordinated in a distorted pyramidal geometry by two N atoms from one dimethyl­glyoxime mol­ecule, two O atoms from one 3,5-dinitro-2-oxidobenzoate ligand and one O atom from a water mol­ecule. Strong hydrogen bonds connect adjacent mol­ecules into a three-dimensional network.