The aim of this study is to construct a high-activity platinum-anchored WO3 electrocatalyst and investigate the effect of platinum content on the catalytic performance. This strategy compared the electrocatalytic performance under acidic conditions by discussing the platinum content and significantly enhances the electrocatalytic activity through nanoscale structure creation and electronic synergies. Therefore, anchoring Pt atoms on WO3 nanoarrays is very important for boosting the activity and stability of electrocatalysis via a hydrothermal co-precipitation approach, Pt-x/WO3@NF (x = 0.1 mmol similar to 0.3 mmol) named as Pt-1/WO3, Pt-2/WO3 and Pt-3/WO3, which enhanced hydrogen evolution reaction(HER) and oxygen evolution reaction (OER) activities. The prepared Pt-2/WO3@NF microspheres showed excellent electrocatalytic activity. When the current density was 10 mA cm(-2), the HER overpotential was 77 mV, the OER overpotential was 126 mV, and the two-electrode water decomposition voltage was 1.4418 V. The bifunctional catalyst shows excellent stability, with virtually no decay in the curves after 100 h stability tests. In addition, nanosheet surface has abundant defects and interface structure, which can maintain excellent conductivity of catalyst and expose more active sites clarify the increased H-2 adsorption for HER activity enhancement. The synthesis of a bifunctional electrocatalyst with both HER and OER properties, presents a novel and intriguing conce

BACKGROUND SKLB1039 is a potent, highly selective, and orally bioavailable EZH2 inhibitor, which significantly inhibited breast tumor growth and metastasis, in pre-clinical studies. In a previously reported synthesis of SKLB1039, the yields of several steps were low which led to an overall yield of less than 10%. In addition, flash chromatography was required for the purification of several intermediates using this route. OBJECTIVE To optimize the synthesis and establish an efficient commercial-scale method for the production of SKLB1039. METHODS The reaction time, solvent, reactant ratio, temperature, and mode of addition of reactants in the reductive amination, hydrolysis, hexahydroisoquinoline formation, hydrogenolysis, condensation and Suzuki cross-coupling reactions were optimized. RESULTS A chromatography-free seven-step process starting from a commercially available material was developed that afforded SKLB1039 in 36% overall yield with > 99% purity. CONCLUSION A cost-effective, high-yielding, and convergent kilo-scale synthesis for the EZH2 inhibitor SKLB1039 was developed. The operation was simple, and the pure product was easily obtained without column chromatography. This method will be economical and convenient for the subsequent industrial scale-up production of SKLB1039, which will be conducive for this promising EZH2 inhibitor to enter clinical studies of its anti-tumor effects.

Two novel nonlinear optical (NLO) chromophores JC-T-TCF and JC-F-TCF utilizing tetramethyljulolidine-based coumarin and tricyanofuran(TCF) as the electron donor and acceptor, respectively, were designed and synthesized. The two chromophores were linked with different π conjugated electron bridge (thiophene group and furan group), which provide the opportunity to study the structure–property relationship of coumarin-based chromophores. Both the novel obtained chromophores exhibited reasonable stability and solvatochromic effect. The theoretical calculation results indicated that both chromophores possess microscopic hyperpolarizability (β) in excess of 320 × 10−30esu, and the chromophore JC-T-TCF utilizing thiophene group as the electron bridge exhibited obviously larger β value (456.8 × 10−30esu). The larger β value, combination with the larger µ value, endowed JC-T-TCF with larger electro-optic activity of 70 pm V−1 at the wavelength of 1310 nm in the guest–host films of chromophores doped into PMMA, which provide the potential application opportunity in the field of optical waveguide devices.

To explore the simple strategy for developing excellent electro-optic (EO) materials, a monolithic EO molecular glass (EOMG1) based on thiophene pi-conjugation and tricyanofuran acceptor (FTC) was synthesized. A tert-butyldiphenylsilyl (TBDPS) group was introduced to the FTC-based nonlinear optic (NLO) chromophore. The glass transition temperature (T-g) of the amorphous films was near 75 degrees C, confirmed EOMG1's glassy state. The theoretical calculation shows that the first hyperpolarizability (beta) and dipole moment (mu) of EOMG 1 were calculated to 584 x 10 (30)esu and 20.73 D. After poling, the poled films EOMG1 diplay large EO activity (r(33)) of 160 pm/V at 1310 nm. The r(33) value is greatly enhanced compared to the reported side-chain EO polymer containing the similar FTC-type NLO chromophore due to the increased loading density of the pure chromophore films and the TBDPS group's role of effective isolation. (C) 2020 Elsevier B.V. All rights reserved.

The detection of nitroaromatic explosives is highly imperative for homeland security and environment protection. For in-field detection of explosives, the devices should be portable and inexpensive and, at the same time, offer fast response and high sensitivity. Optical waveguide sensor is one of the most promsing platforms to realize on-chip nitroaromatics detection due to their capability of large-scale integration, high sensitivity, and immunity to electronmagnetic interference. Meanwhile, polymeric waveguide materials are inexpensive and highly flexible for functionalization. In this study, we synthesize a functional polycarbonate with side-chain donor-p-acceptor dipolar chromophores, and design and fabricate an all-polymer waveguide sensor for the detection of nitrobenzene (NB) and 2, 4-dinitrotoluene (DNT) vapors. The waveguide sensor is based on an unbalanced Mach-Zehnder interferometer (MZI) with two different arms coated with the synthesized polycarbonate. The phase difference between the two arms of the MZI is modulated by the refractive-index change of the coating, which originates from the interaction between dipolar chromophores and electron-deficient NB or DNT vapor in polycarbonate. Our fabricated sensor can reversibly detect NB vapor up to its equilibrium concentration in air (similar to 300 ppm) with a maximum wavelength shift larger than 8 nm. It can irreversibly detect DNT at a much lower concentration (ppb level) with a maximum wavelength shift larger than 5 nm. The response time of the sensor is shorter than 100 s. Our all-polymer MZI, together with the new sensing material, provides a new approach for the realization of low-cost, high-performance explosive detection for in-field applications.

Electron deficient compounds are extensively studied in the field of molecular materials. Compared to the simplest electron acceptors, multi-cyano heterocyclics performed excellent properties in electron-withdrawing ability, thermal stability, etc. This review provides a survey of the synthesis and modifications of two kinds of multi-cyano heterocyclics and their applications.

Novel nonlinear optical (NLO) chromophore using benzo[b]furan moiety and trifluoromethyl-substituted tricyanofuran as the electron donor and acceptor respectively was designed and prepared. The structure of the novel chromophore was determined by NMR spectra, and the photophysical properties were studied via UV-vis spectra. The thermal decomposition temperature (T-d)value of the obtained NLO chromophore reached to 212 degrees C, which endow the chromophore with good thermal stability during the materials processing. The nonlinearity of the chromophore was evaluated through theoretical calculation and electro-optic (K) activity test, and the highest EO coefficient (r(33)) was determined to 28 pm/V at the loading density of 25 wt% in polymethyl methacrylate. (C) 2019 Elsevier B.V. All rights reserved.

Developing new organic chromophores with a large electro-optic coefficient (r33) is highly desirable for fabricating electro-optic (EO) materials.

A polymeric Mach–Zehnder interferometer with photochromic dye doped sensitive films was fabricated for UV light detection at 365 nm.

Monolithic electro-optic (EO) molecular glasses are promising materials for optical waveguide device owing to their high chromophore loading density, high refractive indices and large EO coefficients (r(33) values) for the optimization of in-device figure of merit (n(3)r(33)). However, the stability of EO molecular glasses including the poling induced r33 stability, chemical stability under both high temperature and high voltage in poling is still an obstruction for their real application. Herein, we used the chemical structural optimization, by means of introducing a large conjugated electron-bridge indacenodithiophene (IDT), to synthesize a monolithic EO molecular glass IDTC. Comprehensive properties of excellent glass-forming ability, high thermal stability (T-d = 315 degrees C), and high glass transition temperature (T-g = 137 degrees C) was achieved in monolithic IDTC thin films. More significantly, refractive index of monolithic film was exceptionally high (n = 1.8294 @ 1310 nm and n = 1.7645 @ 1550 nm). The poled IDTC film exhibited the r33 value of 87.6 pm/V with large figure of merit (n3r33: 536 pm/V @ 1310 nm), and the EO activity can be retained over 85% of the initial value after 300 h annealing at 85 degrees C. Meanwhile, it was found that there is no decomposition of IDTC in poled films after high temperature and high voltage poling as well as long term annealing. The poled chromophores are recyclable EO materials for the sustainable application in low-cost EO devices.

A series of highly polarizable nonlinear optical (NLO) chromophores ZJ1-4 with three different configurations, including rod-like, Y-shaped and X-shaped configurations, have been synthesized with facile routes and systematically studied. The resulted chromophores exhibited excellent thermal stabilities. The relationship between molecular configuration and NLO activity was analyzed from the theoretical calculation and experiment. The molecular dipole moment of chromophore ZJ4 was enhanced by X-shaped structure with two acceptors. Meanwhile, the tendency of forming anti-parallel interactions could be inhibited by disk-like molecular configuration with larger steric hindrance. ZJ4 exhibits the largest EO activity of 103 pm/V, and both of molecular and material NLO properties are improved for the chromophore ZJ4 with the X-shaped configuration compared with corresponding benchmark chromophore ZJ1 with rod-like molecular structure.

Four NLO chromophores with different acceptors and modified julolidine donors were facilely synthesized to tune their intramolecular charge-transfer energy gaps for the investigation of the structure-property relationships. The photophysical properties of the UV-Vis absorption spectra, fluorescence spectra and solvatochromism were measured and analyzed to understand the effect of electron-donating strength and electron-withdrawing strength on intramolecular charge-transfer. Density functional theory calculations were carried out to investigate the electron density of the frontier orbitals, energy gap, molecular microscopic dipole moment and hyperpolarizability. The change tendency of the microscopic hyperpolarizability in different dielectric environments in association with the solvatochromism in absorption was analyzed. Meanwhile, the macroscopic electro-optic performance in relation to molecular structure variation and microscopic properties was further analyzed, revealing that chromophores with a larger solvatochromism exhibited higher microscopic hyperpolarizability and macroscopic electro-optic coefficients. Our investigation of the structure-property relationship gave a reliable insight into molecular design for high performance nonlinear optical chromophores.

Two nonlinear optical (NLO) chromophores C1 and C2 based on dithienylethene were designed and synthesized as the ultraviolet NLO switches. The open/close behavior of C1 and C2 were investigated through the UV-vis spectra. Through quantum chemical calculations of the dipole moments, first and second hyperpolarizabilities, etc. we analyzed both opening and closure states of C1 and C2. The NLO switch ability of the chromophores were studied through monitoring of the SHG at the opening/closure states, which were performed under illumination of fourth harmonic generation of the nanosecond Nd:YAG laser (lambda = 266 nm). The obtained results indicated that the maximal SHG changes were observed at energy density equal to about 90 J/m(2), and the samples C1, 2' closure states possess significantly higher value of the second order susceptibility compared to the opening states. After switching off of the external UV light, the induced second order susceptibilities remain up to 150 h without a decrease, which indicated that the obtained chromophores have the potential application as the NLO switches applied in photonics. (C) 2018 Published by Elsevier Ltd.

Novel nonlinear optical chromophores JC-TCF and JC-FTCF using tetramethyljulolidine-based coumarin as the electron-donor and tricyanofuran derivatives as the electron acceptors were designed, synthesized and investigated. The obtained chromophores own good solubility in common solvents, and good compatibility with host polymers. The chromophores also have good thermal stability, and the decomposition temperature exceed 200 degrees C. The UV-vis spectra indicated that JC-TCF and JC-FTCF possess good intramolecular charge transfer ability. Density functional theory (DFT) was used to study the energy gap and first-order hyperpolarizability(beta). After contact poling, the guest-host polymer films of polymethyl methacrylate containing 20% wt JC-TCF and 20% wt JC-FTCF exhibited the highest electro-optic coefficient (r(33)) up to 40 p.m./V and 76 p.m./V respectively, and the results indicated the chromophores' microscopic beta value could be effectively translated to macroscopic EO activity, and the tetramethyljulolidine-based coumarin could be an useful candidate in the development of NLO materials.

Realization of the large electro-optic (EO) activity for organic nonlinear optical (NLO) chromopores with high first order hyperpolarizability requires simultaneous optimization for molecular structure. In this work, we investigated the influences of different pendant groups in chromophore's side chains on the performance of EO materials. A series of NLO chromophores Fl-F3 based on the same conjugated structure but with different pendant groups have been synthesized and systematically investigated. Due to the disperse-red type pendant groups, chromophore F3 shows excellent film-forming ability and relatively high glass transition temperature without blending with optically inactive polymer matrix. The Variable Angle Spectroscopic Ellipsometry (VASE) measurement proves the neat F3 film displays a higher index of refraction value and weak absorption at 1310 nm and 1550 nm, which is beneficial for reducing the operation voltage and optical loss of modulator. Due to the effective isolating ability of pendant groups, the best EO coefficient of the poled F3 film reaches to 81 pm/V, which is two times larger than the value of the same type chromophore in guest-host material. This result, together with high index of refraction and low optical loss, will shed light on a new perspective for the design of new monolithic organic EO materials.

A X-type dendrimer DTPA based on triphenylamine was designed, synthesized, and characterized by NMR and mass spectrometry. The obtained dendrimer possesses good thermal stability. Utilizing DTPA as the hole-transporting layer, the organic light emitting devices (OLEDs) were fabricated and the performances were investigated. The devices test showed that DTPA-based devices exhibited higher efficiency and higher external quantum efficiency (EQE), which indicated DTPA possesses good hole-transporting ability. Moreover, the DTPA-based devices also realized an operation lifetime of 265 h at 20 mA/cm(2). The good hole-transporting ability and stability indicated the obtained DTPA is a promising candidate for hole-transporting materials, and has potential application in OLED devices. (C) 2017 Elsevier B.V. All rights reserved.

We reported the two-step synthesis of triene-based donor–acceptor dyes and demonstrated their applications in electro-optics and optofluidic lasers.

A homologous series of 9,9-diphenyl substituted oligofluorenes end-capped by diphenylamino groups, (Ph)-OF(n)-NPhs, n=1-5, has been synthesized using Suzuki cross coupling reaction as a key step and were fully characterized by H-1 NMR, C-13 NMR, MS, and elemental analyses. The functional properties, including thermal stabilities, linear optical properties, fluorescence and electro-chemical properties, were investigated. The TPA cross sections of these newly synthesized oligofluorenes were measured by the TPF method. Compounds (Ph)-OF(4)-NPh and (Ph)-OF(5)-NPh exhibited larger two-photon absorption cross-sections, about 550 GM and 1390 GM at 800 nm, respectively. (C) 2016 Elsevier B.V. All rights reserved.

A precise and sensitive LC method was developed and further validated for the determination of enantiomeric purity of {(4S)-8-Fluoro-2-[4-(3-methoxyphenyl)-1-piperazinyl]-3-[2-methoxy-5-(trifluoromethyl)phenyl]-3,4-dihydro-4-quinazolinyl} acetic acid (Letermovir). Baseline separation with a resolution >2.8 was accomplished within 10 min using a CHIRALPAK AD (250 mm × 4.6 mm; particle size 5 μm) column, with n-hexane/2-propanol (80:20 v/v) as mobile phase at a flow rate of 1 mL min-1. The eluted analytes were monitored by UV detection at 260 nm. The effects of mobile phase composition and temperature on enantiomeric selectivity as well as resolution of enantiomers were thoroughly investigated. The calibration curves were plotted within the concentration range between 0.003 and 1 mg mL-1 (n = 14), and the recoveries between 98.24 and 101.43% were obtained, with relative standard deviation <1.29%. The limit of detection (LOD) and limit of quantitation (LOQ) for Letermovir were 0.96 and 3.15 μg mL-1; those for its enantiomer were 1.01 and 3.39 μg mL-1, respectively. The developed method was demonstrated to be accurate, robust and sensitive for the determination of enantiomeric purity of Letermovir, especially for the analysis of bulk samples.

By choosing dynamically neighbor nodes according to peer's interest and estimating searching success, a feedback-based P2P network selecting algorithm is presented. It can reduce the number of messages and the time when discovers the first document, increase the number of finding files. By computing dynamic advantage, it can adjust the neighbor node, enhance the P2P network search stability. The theoretical analysis and experiment results show that the performance of the algorithm is superior to the NS selecting algorithms.