Dihydrophenanthrenes from Bletilla formosana

Three new dihydrophenanthrenes, 4-methoxy-9,10-dihydrophenanthrene-1,2,7-triol (1), 1-(4-hydroxybenzyl)-4,7-dimethoxy-9,10-dihydrophenanthrene-2-ol (2), and 1,3,6-tri(4-hydroxybenzyl)-4-methoxydihydrophenanthrene-2,7-diol (3) together with seven known phenanthrene derivatives, six known flavonoids, a bibenzyl and three phenolic compounds were isolated from the whole plant of Bletilla formosana. Their structures were elucidated by spectroscopic, mainly 2D NMR spectrometry and chemical methods.     

Briaexcavatolides X-Z, three new briarane-related derivatives from the gorgonian coral Briareum excavatum

Three new polyoxygenated briarane-type diterpenoids, briaexcavatolides X-Z (1-3), have been isolated from the gorgonian coral Briareum excavatum. The structures, including the relative configurations of briaranes 1-3, were elucidated by spectroscopic methods, particularly in 1D and 2D NMR experiments. The configuration of briarane 1 was further supported by molecular mechanics calculations.     

(Ba, Sr)TiO3纳米棒的反相微乳法制备与表征

在氢氧化钡和氢氧化锶水溶液/Triton X-100/环己烷/正己醇四元W/O型反相微乳液中制备了钛酸锶钡纳米棒, 研究了ω₀值(水与表面活性剂Triton X-100的物质的量之比)、反应物浓度、陈化时间对产品形貌和尺寸的影响, 用TEM, SAED, SEM, EDS和XRD等技术对产品进行了表征. 结果表明, 所得Ba_0.7Sr_0.3TiO₃纳米棒长约500～1200 nm、直径约为50～120 nm; 具有立方相单晶结构. 产品中钡、锶、钛的物质的量之比约为0.7∶0.3∶1.     

水/油型微乳液中球形及棒状钛酸锶钡纳米粒子的控制合成

Barium strontium titanate nanoparticles with spherical and rod-like morphologies were synthesized in water/Triton X-100/n-hexanol/cyclohexane quaternary reverse microemulsion solution. The influences of the molar ratio of water to surfactant (ω₀) and the concentration of reactants on the morphology and size of barium strontium titanate nanoparticles were studied. The structure, compositions and morphology of the prepared products were characterized by XRD, SAED, ICP, EDS and TEM. The results show that the obtained Ba_0.7Sr_0.3TiO₃ spherical nanoparticles with diameters of 20～100 nm and the Ba_0.7Sr_0.3TiO₃ nanorods with diameters of 70～120 nm and lengths up to 600～800 nm are a single crystal, with a cubic phase. The molar ratio for barium, strontium and titanate in products is about 0.7:0.3:1.     

微乳液中球形及棒状SrTiO3纳米粒子的控制合成

以氢氧化锶和钛酸四丁酯为原料, 在水溶液/Triton X-100/环己烷/正己醇反相微乳液体系中制备了直径约为20～80 nm的钛酸锶球形纳米粒子和长约300～1200 nm、直径约为30～150 nm的钛酸锶纳米棒. 用XRD, ICP, TEM, SAED和SEM对样品的结构、成分和形貌进行了表征; 用DLS分析了样品的粒度分布. 结果显示, 水与表面活性剂的物质的量比(ω₀)、反应物浓度、陈化时间等因素都能影响钛酸锶纳米粒子的形貌和尺寸. 所得钛酸锶的锶钛物质的量比约为1.0, 粒度分布较窄, 为立方相单晶结构.     

Efficient acid catalytic synthesis of pyrazolopyrimidines from 1H-pyrazol-5-yl-N,N-dimethylformamidines with cyanamide

The efficient acid catalytic synthesis of pyrazolo [3,4-d]pyrimidine was developed by treating 1H-pyrazol-5-yl-N,N-dimethylformamidine with various aminating agents including N,O-bis(trimethylsilyl)hydroxylamine (NHSiMe₃(OSiMe₃)), cyanamide (NH₂CN), hydroxylamine (NH₂OH), methoxyamine (NH₂OMe), hydrazine (NH₂NH₂), and urea (NH₂C(O)NH₂) in acidic solution at reflux. Based on the experimental result, cyanamide (NH₂CN) and methanesulfonic acid were indicated the best aminating agent and acid mediated solvent. On the other hands, the reactivity tendency was involved the activity of original leaving species grafting on the aminating agents, such as –OH, –OMe, –OSiMe₃, –NH₂, –OSiMe₃, –C(O)NH₂, and –CN, in acid catalytic heterocyclic reaction.     

Insights into Anion-Solvent Interactions to Boost Stable Operation of Ether-Based Electrolytes in Pure-SiOx||LiNi0.8Mn0.1Co0.1O2 Full Cells

Ether solvents with superior reductive stability promise excellent interphasial stability with high-capacity anodes while the limited oxidative resistance hinders their high-voltage operation. Extending the intrinsic electrochemical stability of ether-based electrolytes to construct stable-cycling high-energy-density lithium-ion batteries is challenging but rewarding. Herein, the anion-solvent interactions were concerned as the key point to optimize the anodic stability of the ether-based electrolytes and an optimized interphase was realized on both pure-SiO_x anodes and LiNi_0.8Mn_0.1Co_0.1O₂ cathodes. Specifically, the small-anion-size LiNO₃ and tetrahydrofuran with high dipole moment to dielectric constant ratio realized strengthened anion-solvent interactions, which enhance the oxidative stability of the electrolyte. The designed ether-based electrolyte enabled a stable cycling performance over 500 cycles in pure-SiO_x||LiNi_0.8Mn_0.1Co_0.1O₂ full cell, demonstrating its superior practical prospects. This work provides new insight into the design of new electrolytes for emerging high-energy density lithium-ion batteries through the regulation of interactions between species in electrolytes.     

Structural Characterization of Volatile Components of Rosa Banksiae Ait for Estimation and Prediction of Their Linear Retention Indices and Retention Times

The molecular electronegativity-distance vector （MEDV） was used to describe the molecular structure of volatile components of Rosa banksiae Ait, and QSRR model was built up by use of multiple linear regression （MLR）. Furthermore, in virtue of variable screening by the stepwise multiple regression technique, the QSRR models of 10 and 6 variables and linear retention index （LRI） 10, 7 and 6 varieables were built up by combinating MEDV with the Ultra2 column GC retention time （tR） of 53 volatile components of Rosa Banksiae Air. The multiple correlation coefficients （R） of modeling calculation values of QSRR model were 0.906, 0.906, 0.949, 0.943 and 0.949, respectively. The cross-verification multiple correlation coefficients （RCV） were 0.903, 0.904, 0.867, 0.901 and 0.904, respectively. The results show that the models constructed could provide estimation stability and favorable predictive ability.     

Sinugibberosides A-E, new terpenoids with cyclic peroxyhemiketal from the soft coral Sinularia gibberosa

The organic extract of the soft coral Sinularia gibberosa, collected from the northern Taiwan, has been investigated and resulted in the isolation of five new xeniaphyllane-type diterpenoids with a rare cyclic peroxyhemiketal (3,6-dihydro-1,2-dioxin-3-ol) moiety, sinugibberosides A-E (1-5). The structures of the new terpenoids, including their stereochemistries, were established on the basis of extensive spectroscopic analysis, including 1D and 2D NMR (¹H-¹H COSY, HMQC, HMBC, and NOESY), and by comparison of their NMR data with those of related compounds. Metabolites 1-5 represent the first example of marine terpenoids possessing a cyclic peroxyhemiketal moiety.     

Plasmonic effects in composite metal nanostructures for sensing applications

We have investigated numerically the plasmonic effect on a two-dimensional periodic array of metallic nanostructures. The unit cell of the array has an Ag nanosphere and nanorod pair formed in a single structure. Three-dimensional finite element method is used for the study on the sensing performance within the optical spectra. The study takes into account the influences of the structural and material parameters, the rotational angle of the metal nanostructure, the number of metal nanostructure per unit cell, and the localized surface plasmon resonances. The proposed nanostructures function as a refractive index sensor with a sensitivity of 400 nm/RIU (RIU is the refractive index unit), showing the characteristics of low transmittance (T?=?3.90%), high absorptance (A?=?94.5%), and near-zero reflectance (R?=?0.15%), could be achieved by a triangular arrangement of nanostructures within a unit cell. We also show how the tailoring of the structural parameters relates to the specific sensing schematics of the sensor.

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Graphical abstract x-y sectional plane of electric field intensity, electric force lines (pink lines), energy flows (green arrows) and surface charge density of type 2, corresponding to the surrounding testing medium of (a) n=1.00 and (b) n=1.33 around the PMNSs.