Recently, graphene-based materials have become well-known nonlinear optical materials for the potential application of laser protection. Two new graphene oxide–platinum  complex (GO–Pt) hybrid materials (GO–Pt-1, GO–Pt-2) have been fabricated through covalent modification and electrostatic adsorption of different Pt complexes with GO. The structural and photophysical properties of the resultant hybrid materials were studied. The nonlinear optical properties and optical power limiting (OPL) performance of Pt complexes, GO, and GO–Pt hybrid materials were investigated by using Z-scan measurements at 532 nm. At the same transmittance, the results illustrate that functionalization of GO makes GO–Pt hybrid materials possess better nonlinear optical properties and OPL performance than individual Pt complexes and GO due to a combination of nonlinear scattering, nonlinear absorption, and photoinduced electron and energy transfer between GO and Pt complex moieties. Furthermore, the nonlinear optics and OPL performance of GO–Pt-2 are better than those of GO–Pt-1, due to not only the excellent optical limiting of Pt-2 and more molecules per area of GO but also the way of combination of Pt-2 and GO.Keywords: graphene oxide; nonlinear optics; optical limiting; photophysics; Pt complex;

•Star-shaped 1,3,5-triazine bearing N-aryl chromophore were synthesized.•All compounds exhibit two-photon absorption and aggregation induced emission.•Their values of TPA cross sections are ranged from 3800 GM to 5000 GM.Three star-shaped D-π-A compounds with a 1,3,5-triazine core and N-aryl chromophore (3,6-di-tert-butylcarbazole, phenoxazine and phenothiazine) substituted fluorene arms were designed and synthesized. Their photophysical properties were investigated systematically via spectroscopic and theoretical methods. All compounds exhibit strong 1π–π* transitions in the UV region and intense 1π–π*/intramolecular charge transfer (1ICT) absorption bands in the UV–vis region. Bathochromic shifts of the 1ICT bands were caused by the electron-donating N-aryl chromophores. All compounds exhibit aggregation induced emission properties in a solvent, and relatively high quantum efficiency in solid-states (Φ = 10%–20%). Moreover, these compounds show two-photon absorption (TPA) properties due to their good planarity and large π-conjugation. The largest TPA cross section value reaches up to 5000 GM at 800 nm. The multifunctional properties make these compounds potential candidates for application in organic light-emitting materials and two-photon bioimaging.

An attractive and novel methodology involving Pd/Cu-catalyzed tandem head-to-tail dimerization/cycloisomerization of terminal ynamides for the synthesis of 3,5-disubstituted oxazolones was developed. Under Pd(PPh3)2Cl2/CuI cooperative catalyzed reaction conditions, it provided efficient access to 5-vinyloxazolones with exceptional functional group tolerance and good chemoselectivity. The control experiments demonstrated that Pd(PPh3)2Cl2 serves a key role in the dimerization of terminal ynamides and shows low catalytic activity in the intramolecular cyclization. Moreover, the hetero-Diels–Alder reaction of product 5-vinyloxazolones was also described, which provided polycyclic oxazolones in good yield.

•A highly efficient green PHOLED was designed and fabricated.•Luminous efficiency of PHOLED has been greatly improved by using a double-host system.•The PHOLED exhibits a maximum external quantum efficiency of 19.05%.A highly efficient green phosphorescent organic light-emitting diode (PHOLED) was achieved from two co-evaporated materials, 2,4-diphenyl-6-bis(12-phenylindolo) [2,3-a]carbazole-11-yl)-1,3,5-triazine (DICT) and 9-phenyl-3,6-bis (9-phenylfluoren-9-yl)carbazole (PBFC), in the emitting layer. By utilizing DICT: PBFC = 1:1 as double-host combination and 12 wt% tris(2-phenylpyridine) iridium (Ir(ppy)3) as dopant, the PHOLED exhibits outstanding performance in terms of a maximum external quantum efficiency of 19.05%, a maximum current efficiency of 69.38 cd A−1 and a maximum power efficiency of 77.29 lm W−1, respectively. The device performance is significantly improved compared to those of the single-host material devices based on DICT (15.91%, 57.83 cd A−1 and 72.45 lm W−1) and PBFC (9.19%, 32.67 cd A−1 and 9.64 lm W−1). Furthermore, both host materials show relatively high glass transition temperatures (Tg) of 129.8 °C for DICT and 167.7 °C for PBFC, as well as excellent decomposition temperatures (Td) of 353.5 °C for DICT and 460.3 °C for PBFC respectively. The developed double-host system could be promising combination of host materials, especially for the application of high performance OLED and other organic electronic devices.Download high-res image (189KB)Download full-size image

A novel method was developed to produce 2-nitro-4-methylsulfonylbenzoic acid (NMSBA) from the oxidation of 2-nitro-4-methylsulfonyltoluene (NMST) by oxygen catalyzed by iron(II) phthalocyanine (FePc) and copper(II) phthalocyanine (CuPc). The order of activity for oxidation of NMST was found to be: FePc > CuPc. Meanwhile, major reaction parameters such as concentrations of catalyst and NaOH, reaction temperature and oxygen pressure have been investigated. Through optimization of the reaction parameters, the highest yield of NMSBA and conversion of NMST (up to 53%, 89.3%, respectively) were achieved with oxygen (2.0 MPa), FePc (\(1.0\times 10^{-4}\,\hbox {mol } \hbox {L}^{-1}\)), NaOH (\(0.6\,\hbox {mol } \hbox {L}^{-1}\)), in methanol at 55\(^{\circ }\hbox {C}\) for 8 h. A plausible mechanism for this catalytic process is proposed which involved deprotonation and radical pathways.

•80.1% conversion and 98.5% selectivity remain stable in 72 h continuous ammoximation.•TS-1 microspheres are prepared by spray forming process.•TS-1 microspheres have low membrane fouling and good catalyst stability.•High three-phase reaction efficiency is achieved using JLR.A highly efficient jet loop reactor with ceramic membrane as a separator for a continuous three-phase system was developed to enhance the mass and heat transfer of ammoximation via TS-1 microspheres. It was interesting to find that the jet loop reactor could increase the conversion and selectivity of 2-butanone ammoximation by about 8.1% and 4.5%, respectively, significantly reducing the residence time in comparison with traditional stirred tank reactor. At the same time, a spray forming process was adopted to increase the size of the catalysts from 100–200 nm to 50–200 μm, it can prohibit membrane fouling and improve the catalyst stability. This process had negligible effects on the catalyst’s specific surface area. Finally, the conversion and selectivity remained stable at about 80.1% and 98.5%, respectively, during 72 h of continuous operation of the ammoximation process.Download high-res image (79KB)Download full-size image

•A novel BODIPY-based fluorescent probe for Ca2+ was designed and synthesized.•Upon Ca2+ binding, the probe exhibits red fluorescence (λmax = 631 nm, ΦF = 0.18).•The probe shows a Ca2+ detection limit of 39 μM.A red-emitting Ca2+ probe based on difluoro-boron-dipyrromethene (BODIPY) fluorophore and 1,2-bis(o-aminophenoxy)ethane-N,N,-N′,N'-tetra acetic acid (BAPTA) moiety was designed and synthesized. Four electron-donating 4-methoxyphenyl groups were introduced on BODIPY to make the emission of probe more bathochromic-shifted. Upon Ca2+ binding, the probe exhibits a significant increase of red fluorescence intensity (λmax = 631 nm, ΦF = 0.18), an excellent luminescence ON/OFF ratio (43-fold) and a detection limit of 39 μM. Furthermore, this probe shows desirable sensitivity and selectivity for Ca2+ over other metal ions, which could be potentially applied for Ca2+ detection.A red-emitting Ca2+ probe based on BODIPY fluorophore was designed and synthesized. Upon Ca2+ binding, the probe exhibits a significant increase of red fluorescence intensity (λmax = 631 nm, ΦF = 0.18), an excellent luminescence ON/OFF ratio (43-fold) and a detection limit of 39 μM. Furthermore, this probe shows desirable sensitivity and selectivity for Ca2+ over other metal ions, which could be potentially applied for Ca2+ detection.Download high-res image (230KB)Download full-size image

•Six 4′-phenyl-2,2′:6′,2″-terpyridyl Pt(II) chloride complexes were synthesized.•Their photophysical and electrochemical properties were investigated.•Both ground and excited state absorptions are influenced by attached substituents.A series of 4′-phenyl-2,2′:6′,2″-terpyridyl Pt(II) chloride complexes bearing different aryl substituents (1a–1f) was designed and synthesized. The photophysical properties of these complexes have been systematically investigated. All complexes exhibit strong 1π,π* absorption bands in the UV region; and broad, structureless metal-to-ligand charge transfer (1MLCT) absorption bands in the visible region. When excited at the charge-transfer absorption band, the complexes exhibit room temperature luminescence (λem = 555–614 nm) in CH3CN. The emissions of complexes 1c–1f with electron-donating or extended π-conjugation substituents are assigned to the 3MLCT states. Meanwhile, the emitting state of 1a and 1b exhibits a significant intraligand 3π,π* character. Complexes 1a–1d exhibit moderate triplet transient absorptions from visible to NIR region, where reverse saturable absorption (RSA) occurs. Their photophysical properties have been investigated with the aim to provide a basis for elucidating the structure-property correlations and developing new nonlinear optical materials.A series of 4′-phenyl-2,2′:6′,2″-terpyridyl Pt(II) chloride complexes were synthesized and their photophysical and electrochemical properties were investigated. Their structure-property correlations and triplet transient absorptions properties could be potential utilized in rational design of optical functional materials.Download high-res image (156KB)Download full-size image

•Novel Fe(II) phthalocyanine modified SBA-15 heterogeneous catalysts were prepared.•Efficient catalytic performance for toluene aerobic oxidation.•The selectivity of product depends on the catalyst surface composition and porosity.•Catalyst recycled for three times without significant decrease in catalytic activity.Iron(II) tetracarboxyl phthalocyanine (tcFePc) grafted onto amino-functionalized SBA-15 catalysts for selective oxidation of toluene by oxygen and N-hydroxyphthalimide (NHPI) were studied under mild conditions. The catalysts were characterized by nitrogen adsorption measurements, X-ray diffraction, element analyses, transmission electron microscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Their catalytic performance depended on the isolated amino group and tcFePc contents, which induced the surface composition and porosity of the catalysts. Less isolated amino groups (2.4 μmol/m2) and more grafted tcFePc (20 wt%) facilitate the oxidation efficiency of toluene to benzoic acid. Meanwhile, more isolated amino groups (3.8 μmol/m2) and less grafted tcFePc (11 wt%) weaken the oxidation activity of toluene and tend to form benzaldehyde. Reaction parameters, reaction scope and catalyst reusability were also investigated over 20 wt% tcFePc@NH2-SBA-15-3. Moreover, a plausible pathway for this catalytic process was proposed to involve a radical mechanism.Iron(II) tetracarboxyl phthalocyanine (tcFePc) immobilized onto amino-functionalized SBA-15 catalysts for selective oxidation of toluene by oxygen and N-hydroxyphthalimide (NHPI) were studied under mild conditions. It is found that the surface composition and porosity of these catalysts could tune the selectivity of products in toluene aerobic oxidation.Download high-res image (57KB)Download full-size image

•Three Pt(II) complexes bearing BODIPY acetylide ligands were designed and synthesized.•All complexes exhibit significant AIE and OPL properties.•Emission intensity and triplet excited state lifetime increase when nanoparticles formed.A series of Pt(II) complexes bearing difluoro-boron-dipyrromethene (Bodipy) acetylide ligands and different alkyl/aryl substituted 2,2′-bipyridyl ligands (Pt-1 – Pt-3) were synthesized and characterized. Their photophysics, aggregation included emission (AIE) and optical power limiting properties were systematically investigated via UV−Vis absorption, emission, transient absorption, and nonlinear transmission spectroscopy/technique. These complexes exhibit 1π-π* transitions/metal-to-ligand charge transfer (1MLCT) absorption bands in UV-Vis spectral region and green fluorescence assigned to 1π-π* state mixed with 1MLCT character. All complexes exhibit obvious AIE in CH3CN-water solution system. When water fraction increased, nanoparticles of Pt(II) complexes were formed owing to the aggregation, and the emission intensity and triplet excited state lifetime both increased. In addition, complexes Pt-1 – Pt-3 all exhibit triplet transient absorption (TA) in visible region, where reverse saturable absorption (RSA) could occur. The strength of RSA at 532 nm follows the trend: Pt-2 > Pt-3 > Pt-1. The significant AIE, TA and OPL properties of these complexes would be useful for rational design of transition-metal complexes with high emission quantum yield, broadband excited-state absorption, long excited-state lifetime, and strong nonlinear absorption for multi-functional applications.Download high-res image (211KB)Download full-size image

A highly regio- and stereoselective trans-iodofluorination reaction of ynamides with NIS and Et3N·3HF has been achieved, affording (E)-α-fluoro-β-iodoenamides in moderate to good yields. The reaction proceeds under mild reaction conditions and exhibits good functional group compatibility.

Self-assembled fibrous films are expected to be an efficient approach for volatile organic amine (VOA) detection because of their fast response and high sensitivity and facile preparation of portable instruments. Herein, two D–π–A type salicylaldehyde derivatives functionalized naphthalimides (SFN) and tert-butyl carbazole (SFC) were synthesized, and their photophysical properties were investigated systematically. Both compounds display significant aggregation-induced emission behaviors originating from twisted intramolecular charge transfer (TICT) and restricted intramolecular rotation (RIR). Moreover, hydrogen bonding and π–π interactions with the assistance of dipole–dipole interactions enable the formation of self-assembled fibrous films from SFN and SFC, respectively. In particular, nanofibril-based films are introduced to detect VOA vapors with high performance through deprotonation and the Schiff base reaction. The fluorescence intensity of the films is quenched dramatically for SFN and enhanced significantly for SFC after exposure to the VOA vapors. These salicylaldehyde derivatives can be used for the design of efficient fluorescent chemosensors, and their self-assembled fibrous films are promising sensors for VOA detection.

Four heteroleptic cationic Ir(III) complexes [(X)2Ir(L2)]+PF6− were designed and synthesized, where L2 = 3,6-di-tert-butyl-9-(4-(4,5-dimethyl-2-(pyridin-2-yl)-1H-imidazol-1-yl)butyl)-9H-carbazole, X = difluorophenylpyridine (dfppy) (1), dimethylphenylpyridine (dmppy) (2), difluorophenylquinoline (dfpq) (3), dimethylphenylquinoline (dmpq) (4). Their photophysical properties have been systematically investigated via a series of spectroscopic methods. All complexes show fluorescence–phosphorescence dual-emission, aggregation-induced fluorescence emission (AIFE) and aggregation-induced phosphorescence emission (AIPE) in a solvent. Meanwhile, green to red emission colors are exhibited in the solid state. Noticeably, complex 2 shows evident piezochromic and vapochromic behaviors. The emission colors of complex 2 can be reversed from green to yellow upon grinding and CH2Cl2 fuming, which is further demonstrated using solid state and powder X-ray diffraction spectroscopy. Additionally, complex 2 is used in data security protection and provides a strategy to design smart luminescent materials.

With Et3N·3HF as the fluorinating reagent, a copper(I)- or silver(I)-catalyzed β/α-site-regiocontrolled trans-hydrofluorination of alkynamides has been achieved, affording the corresponding fluoro enamides in moderate to nearly quantitative yields with high regio- and stereoselectivity, respectively. The reaction proceeds under mild reaction conditions and exhibits good functional group tolerance. Further, the deuterium-labeling experiment confirmed the existence of the alkenylcopper intermediate.

A mild and efficient methodology involving the I2/TBHP-mediated intermolecular iodoamination of ynamides with amines for the synthesis of α-amino-β,β-diiodo-enamides was developed. This reaction provides the first intermolecular iodoamination of terminal alkynes to diiodo-enamines and can be easily applied to a wide range of substrates.

A novel chalcogen-mediated oxyfunctionalization mode of ynamides for the synthesis of α-chalcogenyl acrylamides has been developed. Independent of metal catalysts, external oxidants and additives, this mild process afforded a range of structurally diverse α-chalcogenyl acrylamides, including α-selanyl acrylamides and α-tellanyl acrylamides. Interestingly, diverse ynamides tolerated in this approach gave different stereoselectivities.

With Et3N·3HF as the fluorination reagent, (IPr)CuF-catalyzed α-site regiocontrolled trans-hydrofluorination of ynamides has been achieved, affording (Z)-α-fluoroenamides in moderate to excellent yields. It was interesting to note that the regioselectivity of the reaction is reversed to that observed in the (Ph3P)3CuF-catalyzed hydrofluorination of ynamides. Additionally, a variety of different ynamides including oxazolidinonyl-, imidazolyl-, and N-sulfonyl ynamides were suitable for the reaction system and the subsequent oxidation of the fluorinated products enables a convenient synthesis to α-fluoroimides.

•A series of terpyridyl Pt(II) complexes were synthesized and characterized.•The photophysics and nonlinear absorption of these complexes were investigated.•Three complexes exhibit RSA for the ns laser pulses at 532 nm.A series of 4-phenyl-2,2′; 6′,2″-terpyridyl Pt(II) complexes bearing different σ-alkynyl ancillary ligands (1a–1f) were synthesized and characterized. All complexes exhibit strong 1π,π* absorption bands in the UV region; and broad, structureless metal-to-ligand charge transfer (1MLCT)/ligand-to-ligand charge transfer (1LLCT) absorption bands in the visible region. When excited at the charge-transfer absorption band, the complexes exhibit yellow to red luminescence (λmax = 553–608 nm) in CH3CN at room temperature, which is attributed to the 3MLCT/3LLCT state, except 1c. The emitting state of 1c exhibits a significant intraligand 3π,π* character, which is originated from the naphthalimide acetylide ligand. Complexes 1a–1c exhibit moderate triplet transient absorptions from visible to NIR region, where reverse saturable absorption (RSA) occurs. The photophysical, electrochemical and nonlinear absorption properties of these Pt(II) complexes can be tuned drastically by the different acetylide ligand, which would be useful for rational design of broadband nonlinear absorption materials.A series of 4-phenyl-2,2′; 6′,2″-terpyridyl Pt(II) complexes bearing different σ-alkynyl ancillary ligands (1a–1f) were synthesized and characterized. Their photophysical, electrochemical and nonlinear absorption properties can be tuned drastically by the acetylide ligand, which would be useful for rational design of transition-metal complexes for organic light-emitting materials and broadband nonlinear absorption materials.

On account of the biological harmfulness of hydrazine, we have designed and synthesized a novel red-emitting fluorescent probe (1) based on 3-hydroxyflavone. The probe could selectively and sensitively detect hydrazine over other primary amines, cations and anions. Moreover, we verified the mechanism of probe 1 for detecting hydrazine through a 1H NMR titration and MS spectral analysis. Importantly, the probe could selectively detect hydrazine in different water samples which showed its potential for practical applications.

Two aza-boron-diquinomethene (aza-BODIQU) complexes bearing phenyl and carbazyl substituents were synthesized and characterized. Their photophysical properties were investigated systematically via spectroscopic and theoretical methods. Both complexes exhibit strong 1π-π* transition absorptions (λabs = 400–540 nm) and intense fluorescent emissions (λem = 440–600 nm, ΦPL = 0.93 and 0.78) in CH2Cl2 solution and in solid state at room temperature. Compared to the complex with phenyl groups, the complex bearing carbazyl groups shows significant bathochromic shift in both absorption and emission. This could be attributed to the larger π-electron conjugation of the carbazole unit and intramolecular charge transfer feature from carbazole to aza-BODIQU component. In addition, the complexes exhibit intense photoluminescence and good stability on antacid, anti-alkali and stability in printing ink samples, which makes them potential dopants for the application of fluorescent security inks.

•A ESIPT turn-on metal-free fluorescent probe for sensing nitroxyl (HNO) was developed.•Large emission spectral shift from weak 404 nm to strong 520 nm in responding to HNO, as a consequence of the ESIPT turn-on.•The probe exhibits a selective response to HNO over other biological reductants in solution.•The probe was applied for quantitative detection of HNO in bovine serum with satisfactory results.A excited-state intramolecular proton transfer (ESIPT) fluorescent turn-on probe (FLA-1) for the detection of nitroxyl (HNO) is designed and synthesized. It consists of a flavone derivative moiety as the fluorophore, linked via an ester moiety to a diphenylphosphinobenzoyl group as a recognition receptor, which forms an aza-ylide upon reaction with HNO. Intramolecular attack of the aza-ylide on the ester carbonyl group releases a fluorescent flavone derivative. In addition, the results showed that FLA-1 exhibited a selective response to HNO over other biological reductants and can quantitatively detect HNO in the range of 0–20 μM with the detection limit of 1.28 × 10−7 M in aqueous solution. Importantly, FLA-1 was successfully applied to detect HNO in the range of 2–20 μM with the detection limit of 3.96 × 10−7 M in complex biological samples (serum) demonstrating its value in practical application.

A series of β-diketone derivatives bearing tetraphenylene (TPE) moieties were synthesized and characterized. Their photophysical properties were investigated systematically via spectroscopic and theoretical methods. All compounds exhibit broad absorption bands between 300 and 450 nm, which are assigned to the 1π-π* transition of the conjugated system mixed intramolecular charge-transfer (ICT) transitions. Meanwhile, the emission of these compounds in solution at room temperature (λem = 458 ~ 509 nm) can be attributed to the 1π,π*/1ICT state. Introduction of freely rotatable TPE to conventional β-diketone luminophors quenches their light emissions in the solutions, but endows these molecules with aggregation-induced emission (AIE) characteristics in the condensed phase due to the restriction of intramolecular rotation. The spectroscopic studies and theoretical calculations indicate that the photophysical properties of these β-diketone derivatives can be tuned by the appended substituents, which would be useful for rational design of AIE compounds with high solid state luminescence performance. Furthermore, these AIE-active compounds exhibited distinct piezofluorochromic properties and switched reversibly upon grinding-fuming. Their photophysical properties have been investigated with the aim to provide a basis for elucidating the structure-property correlations and developing new multi-stimuli responsive luminescent materials.

A series of aza-boron-diquinomethene complexes (1a–1e) bearing different N-aryl chromophores were synthesized and characterized by multinuclear NMR spectroscopy, X-ray crystallography, optical absorption and emission spectroscopy, and elemental analysis. These robust thermal complexes possess tunable intense luminescence from blue to red with relatively high emission quantum yields. The introduction of different N-aryl chromophores into the aza-BODIQU core significantly tuned the emission colors. The relationship between their structures and properties was investigated systematically via spectroscopic methods and simulated by density functional theory (DFT) calculations. Additionally, the application of 1c as a pH sensor with a remarkable colour-changing property has been investigated. All these results indicate that these complexes exhibit robust thermal stability, tunable photophysical properties, relatively high photoluminescence quantum yields and protonation effect, making these complexes potential candidates for pH sensors, bioimaging probes and organic light-emitting materials.

Two efficient processes based on the iodocyclization of ynamides have been developed: (i) N-alkynyl tert-butyloxycarbamates were found to undergo a rare 6-exo-dig ring closure reaction affording 1,3,5-oxadiazin-2-ones by using acetonitrile as solvent; (ii) In the absence of acetonitrile, N-alkynyl tert-butyloxycarbamates could undergo 5-endo-dig cyclization providing oxazolones.

•A hole transporting material was synthesized and characterized.•The compound exhibits high hole mobility and excellent thermal stability.•The resulting device exhibits higher efficiency compared with NPB-device.A hole-transporting material, N1,N1,N3,N3-tetra([1,1′-biphenyl]-4-yl)-N5,N5-diphenylbenzene-1,3,5-triamine (TDAB-BP), was synthesized by di([1,1′-biphenyl]-4-yl)amine and 3,5-dichloro-N,N-diphenylaniline via Buchwald–Hartwig coupling reaction. The material exhibit high hole mobility, excellent thermal and morphological stability. TDAB-based OLED device exhibited the highest performance in terms of the maximum current efficiency (9.34 cd/A), maximum power efficiency (5.89 lm/W), and maximum external quantum efficiency (6.61%), which is significantly improved than that of the standard device based on 4,4′-bis[N-(1-naphthyl)-N-phenyl-amino]-biphenyl (NPB) (7.12 cd/A, 4.90 lm/W and 5.31%). Furthermore, TDAB-BP shows a higher decomposition temperature (Td) of 505 °C than that of NPB (418 °C). This material could be a promising hole-transporting material, especially for the high-temperature applications of OLEDs and other organic electronic devices.A hole-transporting material TDAB-BP was synthesized, which exhibits high hole mobility, excellent thermal and morphological stability. Blue OLED device based on TDAB-BP exhibits high performance with the maximum current efficiency of 9.34 cd/A, maximum power efficiency of 5.89 lm/W and maximum external quantum efficiency of 6.61%. TDAB-BP could significantly improve the device performance than traditional NPB.

It is important to understand the interface and interaction between graphene layers and SiC surfaces as well as the interaction of key intermediate Si and C atoms with these surfaces and interfaces in epitaxial graphene growth on SiC substrates. In this study, we used the DFT-D2 method, which includes critical long-range van der Waals forces in graphene–SiC interaction, to study interface and interaction between mono-, bi-, and trilayer graphene and Si-face and C-face of SiC substrates as well as single Si and C atom interactions with these surfaces and interfaces. Our results show that the interface, which includes the bottom layer of graphene and top layer of SiC, has a major reconstruction due to the strong interaction of C–Si or C–C covalent bonds. The interaction energy of graphene bottom layer with the C-face is significantly lower than that with the Si-face, although there are stronger C–C covalent bonds and shorter interlayer distances at the graphene–C-face than that at the graphene–Si-face. In contrast, the interaction energy of second layer with bottom layer of graphene on the C-face is obviously higher than that on the Si-face. In particular, the top two layers almost float on the bottom layer of trilayer graphene on the Si-face. Furthermore, the bottom layer on Si-face with a metallic surface is more chemically active than that on the C-face with a semiconducting surface. Compared with the interaction of Si and C atoms with these surfaces and interfaces, the results show that Si atom has a stronger interaction with both bare Si-face and C-face than the C atom. Moreover, the interactions of Si and C atoms with bare Si-face are stronger than that with bare C-face. More importantly, once SiC surfaces are covered by a first carbon layer, C atom prefers to stay at the interface between the existing carbon layer and Si-face or C-face rather than on the surface of the existing carbon layer. In contrast, Si atom only prefers to stay on the surface of the existing carbon layer, and not on the interface. The difference in Si and C atoms on this issue may result in the epitaxial growth of new carbon islands or layers at the interface between the existing carbon layer and Si-face or C-face. All these findings provide insight into the controlled growth of epitaxial graphene on SiC substrates and the design of graphene–SiC based electronic devices.

In this paper, a facile near infrared (NIR, 650–900 nm) probe 4-dimethylamino-2′-hydroxychalcone (NIR-LP) based on the excited state intramolecular proton transfer (ESIPT) – aggregation induced emission (AIE) processes for the detection of the latent fingerprints (LFPs) was developed for the first time. The probe can distinguish the fresh LFPs, but also recognize the aged (10 days) LFPs.

Two polycyclic aromatic hydrocarbons bearing trimethylsilylethynyl groups were designed and synthesized as new colorimetric and ratiometric fluorescent probes for fluoride anion. Both probes exhibit high specific selectivity and sensitivity for F− compared to other anions. When F− is added to the solution of the probe, the trimethylsilyl substituents can be removed immediately, and the color of the solution changes from yellow to colorless under ambient light. Moreover, test papers based on the probes are prepared, which could be applied to detect F− in organic phase.

A mild and efficient methodology involving Pd(PPh3)4-catalyzed intramolecular cyclization of N-alkynyl alkyloxycarbamates with CuCl2 or CuBr2 for the synthesis of 4-halo-oxazolones was developed. This reaction exhibiting good functional tolerance provided a new, efficient, and rapid synthetic process to 4-halo-oxazolones. The resulting 4-halo-oxazolones can serve as great potential precursors for the 3,4,5-trisubstituted oxazolones via a Pd-catalyzed cross-coupling reaction.

A synthetic method for 2-formylcyclopent-2-enecarboxylic acid is described. This procedure comprises two steps. The first step is a [2 + 2] cycloaddition reaction, and the second step is a hydrolysis and ring-opening reaction. A plausible mechanism of the hydrolysis and ring-opening reaction was supposed. Then, the effects of different solvents, base mol ratio, concentration of base, and reaction temperature on the yield of the second step were studied. Finally, under the obtained optimized conditions, the product was achieved and isolated in 59.4 % yield, which was more than double the ones reported previously. An improved and efficient procedure for the synthesis of 2-formylcyclopent-2-enecarboxylic acid has been developed.

A novel AIE-active boron-difluoride complex (PTZ) was synthesized which exhibits multi-stimuli responsive characteristics. Its colours and emissions can be switched by mechanical grinding, organic solvent vapours and acid/base vapours. This complex can be utilized in data encryption and decryption based on the protonation–deprotonation effect.

It is a long-standing controversy whether metal carbide clusters do exist during the nucleation and growth process of single-walled carbon nanotubes (SWCNTs). In the current work, we are trying to elucidate the carbon nucleation on nickel carbides during the initial stages based on density functional theory calculated formation energy and chemical potential for a series of Ni55Cn carbides (n is the number of carbon atoms dissolved in the Ni55 cluster). It is found that the formation energies of the Ni55Cn carbides decrease gradually with an increase of dissolved carbon atomic numbers, meaning the Ni55Cn carbides are thermodynamically stable. Meanwhile, the calculated chemical potentials indicate that not only nickel carbides are preferentially formed during the initial stage of the SWCNT nucleation, but also saturated nickel carbides may be able to exist during the nucleation and growth process of SWCNTs. In addition, the nickel carbides have a high selectivity for the formation of the carbon pentagon and carbon structures with pentagon-incorporated end-edge according to the adsorption energies. All of these findings provide opportunities in controlling the growth of the SWCNTs.

The copper(I)-catalyzed hydroboration of alkynamides with B2pin2 afforded the alkenamide boronates in 66% to nearly quantitative yields with high regio- and stereo-selectivity. It was interesting to note that the regio-selectivity of the reaction is opposite to that observed in the carbometallation reaction of alkynamides, and the resulting alkenyl boronates provided access to α,β-disubstituted (Z)-alkenamides through further elaboration.

•The novel probe can easy to be synthesized.•This sensor exhibits high selectivity and sensitivity for ClO−.•Effective utilization of the probe for detection of ClO− in living cells.•The probe has high fluorescence yield and biocompatibility to monitor ClO−.A highly sensitive and selective fluorescein-based probe 1 for hypochlorite anion was synthesized. The probe 1 has favorable characteristics for biological imaging, including high water solubility, high fluorescence yield, pH-independent fluorescence, and biocompatibility. Results show that it has a detection limit of 40 nM to hypochlorite anion. In addition, confocal fluorescence microscopy imaging using RAW264.7 cells showed that the new probe 1 could be used as an effective fluorescent probe for detecting HOCl in living cells.

A series of anthranilic diamides analogs (5a–x) containing 1,3,4-oxadiazole rings were synthesized and characterized by 1H NMR, 13C NMR and mass spectrometry. The structure of N-(4-chloro-2-methyl-6-(5-(thiophen-2-yl)-1,3,4-oxadiazol-2-yl)phenyl)methacrylamide (5u) was determined by X-ray diffraction crystallography. The insecticidal activities of these new compounds against diamondback moth (Plutella xylostella) were evaluated. Preliminary bioassays indicated that some of these compounds exhibited good insecticidal activities against P. xylostella, especially 3-bromo-N-(4-bromo-2-methyl-6-(5-(pyrazin-2-yl)-1,3,4-oxadiazol-2-yl)phenyl)-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxamide (5d), which displayed 100%, 80.95% and 57.14% activity against P. xylostella at 40 μg mL−1, 10 μg mL−1 and 4 μg mL−1, respectively. The relationship between structure and insecticidal activity was discussed. The density functional theory (DFT) studies could be helpful to understand the various insecticidal activities.

SBA-15 supported Cu2O nanoparticles (Cu2O/SBA-15) have been fabricated and characterized. The as-prepared Cu2O/SBA-15 is a highly effective catalyst for cyanation of aryl iodides using non-toxic K4[Fe(CN)6] as a cyanide source in dimethylformamide (DMF). The approach achieves a high selectivity and an excellent yield without using any ligands and base additives. Moreover, the Cu2O/SBA-15 catalyst shows wide functional group tolerance and reusability with a slight loss of activity.

The authors described a short and highly enantioselective route to (R)-salmeterol involving asymmetric synthesis of cyanohydrin followed by nucleophilic substitution with 6-(4-phenylbutoxy) hexyl methanesulfonate.

•The D-Au film was first used in the immunosensor as substrate platform.•A novel Pt NWs@g-SBA-15/Thi was first applied as an Ab2 labeled probe.•The immunosensor exhibited a wide detection range and a low limit of detection.•The immunosensor showed a promising capacity for applying in clinical detection.A novel thionine unites with platinum nanowire inlaid globular SBA-15 (Pt NWs@g-SBA-15/Thi) not only utilizes as an efficient electrical signal probe but also constitutes an amplifying system with double-deck gold film (D-Au film) have been applied to the fabrication of sandwich-type immunosensor for detecting hepatitis B surface antigen (HBs Ag). The D-Au film can accelerate the electron transfer on the electrode interface due to the tunneling effect between the two Au films and can improve the load capacity of primary antibodies (Ab1) because of the good biocompatibility. The Pt NWs@g-SBA-15/Thi with uniform globular morphology not only can effectively reduce the spatial limitation for loading the secondary antibodies (Ab2) but also can provide outstanding pore accessibility of guest species from outside and offer catalytically active sites in a large scale. Besides, the presence of Thi can well enhance the electrical conductivity of Pt NWs@g-SBA-15/Thi. With the good cooperation between D-Au film and Pt NWs@g-SBA-15/Thi, a linear relationship between current signals and the concentrations of HBs Ag was obtained in the wide range from 10 fg/mL to 100 ng/mL and the detection limit of HBs Ag was 3.3 fg/mL (signal-to-noise ratio of 3). Furthermore, the designed immunosensor with excellent selectivity, reproducibility and stability shows excellent performance in detection of human serum samples and provides a promising capacity for detecting a wide range of other tumor markers in clinical application.

A novel chalcogen-mediated oxyfunctionalization mode of ynamides for the synthesis of α-chalcogenyl acrylamides has been developed. Independent of metal catalysts, external oxidants and additives, this mild process afforded a range of structurally diverse α-chalcogenyl acrylamides, including α-selanyl acrylamides and α-tellanyl acrylamides. Interestingly, diverse ynamides tolerated in this approach gave different stereoselectivities.

The copper(I)-catalyzed hydroboration of alkynamides with B2pin2 afforded the alkenamide boronates in 66% to nearly quantitative yields with high regio- and stereo-selectivity. It was interesting to note that the regio-selectivity of the reaction is opposite to that observed in the carbometallation reaction of alkynamides, and the resulting alkenyl boronates provided access to α,β-disubstituted (Z)-alkenamides through further elaboration.

A mild and efficient methodology involving the I2/TBHP-mediated intermolecular iodoamination of ynamides with amines for the synthesis of α-amino-β,β-diiodo-enamides was developed. This reaction provides the first intermolecular iodoamination of terminal alkynes to diiodo-enamines and can be easily applied to a wide range of substrates.

A series of aza-boron-diquinomethene complexes (1a–1e) bearing different N-aryl chromophores were synthesized and characterized by multinuclear NMR spectroscopy, X-ray crystallography, optical absorption and emission spectroscopy, and elemental analysis. These robust thermal complexes possess tunable intense luminescence from blue to red with relatively high emission quantum yields. The introduction of different N-aryl chromophores into the aza-BODIQU core significantly tuned the emission colors. The relationship between their structures and properties was investigated systematically via spectroscopic methods and simulated by density functional theory (DFT) calculations. Additionally, the application of 1c as a pH sensor with a remarkable colour-changing property has been investigated. All these results indicate that these complexes exhibit robust thermal stability, tunable photophysical properties, relatively high photoluminescence quantum yields and protonation effect, making these complexes potential candidates for pH sensors, bioimaging probes and organic light-emitting materials.

With Et3N·3HF as the fluorination reagent, (IPr)CuF-catalyzed α-site regiocontrolled trans-hydrofluorination of ynamides has been achieved, affording (Z)-α-fluoroenamides in moderate to excellent yields. It was interesting to note that the regioselectivity of the reaction is reversed to that observed in the (Ph3P)3CuF-catalyzed hydrofluorination of ynamides. Additionally, a variety of different ynamides including oxazolidinonyl-, imidazolyl-, and N-sulfonyl ynamides were suitable for the reaction system and the subsequent oxidation of the fluorinated products enables a convenient synthesis to α-fluoroimides.

A novel AIE-active boron-difluoride complex (PTZ) was synthesized which exhibits multi-stimuli responsive characteristics. Its colours and emissions can be switched by mechanical grinding, organic solvent vapours and acid/base vapours. This complex can be utilized in data encryption and decryption based on the protonation–deprotonation effect.

Four heteroleptic cationic Ir(III) complexes [(X)2Ir(L2)]+PF6− were designed and synthesized, where L2 = 3,6-di-tert-butyl-9-(4-(4,5-dimethyl-2-(pyridin-2-yl)-1H-imidazol-1-yl)butyl)-9H-carbazole, X = difluorophenylpyridine (dfppy) (1), dimethylphenylpyridine (dmppy) (2), difluorophenylquinoline (dfpq) (3), dimethylphenylquinoline (dmpq) (4). Their photophysical properties have been systematically investigated via a series of spectroscopic methods. All complexes show fluorescence–phosphorescence dual-emission, aggregation-induced fluorescence emission (AIFE) and aggregation-induced phosphorescence emission (AIPE) in a solvent. Meanwhile, green to red emission colors are exhibited in the solid state. Noticeably, complex 2 shows evident piezochromic and vapochromic behaviors. The emission colors of complex 2 can be reversed from green to yellow upon grinding and CH2Cl2 fuming, which is further demonstrated using solid state and powder X-ray diffraction spectroscopy. Additionally, complex 2 is used in data security protection and provides a strategy to design smart luminescent materials.

An attractive and novel methodology involving Pd/Cu-catalyzed tandem head-to-tail dimerization/cycloisomerization of terminal ynamides for the synthesis of 3,5-disubstituted oxazolones was developed. Under Pd(PPh3)2Cl2/CuI cooperative catalyzed reaction conditions, it provided efficient access to 5-vinyloxazolones with exceptional functional group tolerance and good chemoselectivity. The control experiments demonstrated that Pd(PPh3)2Cl2 serves a key role in the dimerization of terminal ynamides and shows low catalytic activity in the intramolecular cyclization. Moreover, the hetero-Diels–Alder reaction of product 5-vinyloxazolones was also described, which provided polycyclic oxazolones in good yield.

It is a long-standing controversy whether metal carbide clusters do exist during the nucleation and growth process of single-walled carbon nanotubes (SWCNTs). In the current work, we are trying to elucidate the carbon nucleation on nickel carbides during the initial stages based on density functional theory calculated formation energy and chemical potential for a series of Ni55Cn carbides (n is the number of carbon atoms dissolved in the Ni55 cluster). It is found that the formation energies of the Ni55Cn carbides decrease gradually with an increase of dissolved carbon atomic numbers, meaning the Ni55Cn carbides are thermodynamically stable. Meanwhile, the calculated chemical potentials indicate that not only nickel carbides are preferentially formed during the initial stage of the SWCNT nucleation, but also saturated nickel carbides may be able to exist during the nucleation and growth process of SWCNTs. In addition, the nickel carbides have a high selectivity for the formation of the carbon pentagon and carbon structures with pentagon-incorporated end-edge according to the adsorption energies. All of these findings provide opportunities in controlling the growth of the SWCNTs.