Synthesis, crystal structure and optical properties of the new lead fluoride borate—Pb2BO3F

A new compound, Pb₂BO₃F, has been grown by high temperature solution method from the PbO–PbF₂–B₂O₃ system for the first time. The crystal structure of this compound has been identified by single crystal X-ray diffraction analysis. It crystallizes in the hexagonal system, space group P6₃/m (No. 176) with unit-cell parameters a=7.2460(3) Å, c=14.5521(17) Å, Z=6, V=661.69(9) ų. Its structure was solved by the direct methods and refined to R₁=0.0163 and wR₂=0.0367. The structure of Pb₂BO₃F consists of the distorted PbO₃F₂ groups and BO₃ triangles, which are all symmetric with each other in the gestalt structure to the extent that the Pb₂BO₃F compound crystallizes in the symmetric space group. The powder X-ray diffraction pattern of the Pb₂BO₃F has been measured. The BO₃ functional groups presented in the sample were identified by FTIR spectrum. The DTA curve of Pb₂BO₃F suggests that Pb₂BO₃F melts congruently at 448 °C.     

固体热载体热解霍林河褐煤实验研究

在处理量为10kg/h的粉煤-固体热载体移动床实验装置上,以循环灰为热载体对其进行了热解特性评价实验.考察了热解温度(460℃~610℃)、反应时间(6min~8min)及煤粒粒径对热解产物产率和组成的影响.结果表明,随着热解温度的升高,气体产率增大;焦油产率在520℃时达到最大值4.94%.热解煤气的热值为19.80...     

(S,S)-TsDPEN-Ru催化不对称氢转移还原β-胺基酮及在度洛西汀合成中的应用

报道了甲酸/三乙胺体系中,(S,S) -TsDPEN-Ru络合物催化的不对称氧转移反应合成(S)-γ-胺基醇的方法.考察了不同底物的反应性能,β-单/二烷基胺基-2-噻吩酮在该还原体系中氧解得到1-(2-噻吩基)-1-丙酮;氮原子上吸电子基取代的底物以高收率、高立体选择性(＞95％e.e.)得到还原产物.将这一反应用于...     

含吡唑甲酰胺基E-β-法尼烯类似物的设计、合成及生物活性

为发现防治蚜虫的新型活性化合物,以蚜虫报警信息素E-β法尼烯(EBF)为先导,设计合成了20个未见文献报道的含吡唑环甲酰胺基EBF类似物,所有化合物结构均通过1H NMR,IR及HRMS确证.初步生物活性研究表明,部分目标化合物对五日龄豆蚜(Aphis craccivora Koch)在600mg/L时表现出较好的杀虫活性,其中5a及5k对豆蚜活性与商品化药剂氟虫腈及先导化合物EBF相当,甚至优于EBF.对影响目标化合物的活性因素进行了初步探讨.     

超高效液相色谱-串联质谱快速筛查葡萄酒中的14种禁用食品添加剂

建立了同时测定葡萄酒中14种禁用食品添加剂的超高效液相色谱-电喷雾电离串联质谱(UPLC-ESI-MS/MS)分析方法。采用UPLC BEH C18(100 mm×2.1 mm×1.7 mm)色谱柱,对流动相的组成、缓冲液离子强度及质谱的各种参数进行了优化。结果表明,流动相的离子强度对食品添加剂的质谱检测有重要影响,以含1 mmol/L甲酸铵-甲酸缓冲液(pH 3.9)-乙腈为流动相,梯度洗脱,柱温35℃,可以在6 min内完成14种食品添加剂的分离和检测。在ESI负离子模式下,采用选择离子监测方法进行测定时,除三氯蔗糖、日落黄和酸性红13的检出限分别为10,2和2 mg/L外,其它11种的检出限在0.01~1.0 mg/L之间。回收率为93.8%~106%,相对标准偏差小于3.1%。本方法快速、准确、灵敏度高,可用于葡萄酒及其它复杂基质食品中的低剂量、多种禁用食品添加剂的同时筛查。     

Copolymers comprising 2,7-carbazole and bis-benzothiadiazole units for bulk-heterojunction solar cells

On the basis of theoretical considerations of the intramolecular charge transfer (ICT) effect, we have designed a series of donor (D)–acceptor (A) conjugated polymers based on bis‐benzothiadiazole (BBT). A PPP‐type copolymer of electron‐rich 2,7‐carbazole (CZ) and electron‐deficient BBT units poly[N‐(2‐decyltetradecyl)‐2,7‐carbazole‐co‐7,7′‐{4,4′‐bis‐(2,1,3‐benzothiadiazole)}] ( PCZ‐BBT ), a PPV‐type copolymer poly[N‐(2‐decyltetradecyl)‐2,7‐carbazolevinylene‐co‐7,7′‐{4,4′‐bis‐(2,1,3‐benzothiadiazolevinylene)}] ( PCZV‐BBTV ), and a tercopolymer based on carbazole, thiophene, and BBT poly[N‐(2‐decyltetradecyl)‐2,7‐(di‐2‐thienyl)carbazole‐co‐7,7′‐{4,4′‐bis‐(2,1,3‐benzothiadiazole)}] ( PDTCZ‐BBT ) have been synthesized to understand the influence of BBT acceptor structure and linkage on the photovoltaic characteristics of the resulting materials. Both the HOMO and LUMO of the resulting polymers are found to be deeper‐lying than those of benzothiadiazole‐based polymers. The measured electrochemical band gaps (eV) are in the following order: PDTCZ‐BBT (1.65 eV) < PCZV‐BBTV (1.69 eV) < PCZ‐BBT (1.75 eV). All the polymers provide a photovoltaic response when blended with a fullerene derivative as an electron acceptor. The best cell reaches a power conversion efficiency of 2.07 % estimated under standard solar light conditions (AM1.5G, 100 mW cm^?2). We demonstrate for the first time that BBT‐based polymers are promising materials for use in bulk‐heterojunction solar cells.     

Mesomorphism and luminescence properties of platinum(II) complexes with tris(alkoxy)phenyl-functionalized pyridyl pyrazolate chelates

A series of new mesomorphic platinum(II) complexes 1 – 4 bearing pyridyl pyrazolate chelates are reported herein. In this approach, pyridyl azolate ligands have been strategically functionalized with tris(alkoxy)phenyl groups with various alkyl chain lengths. As a result, they are ascribed to a class of luminescent metallomesogens that possess distinctive morphological properties, such as their intermolecular packing arrangement and their associated photophysical behavior. In CH₂Cl₂, independent of the applied concentration in the range 10^?6–10^?3 M , all Pt^II complexes exhibit bright phosphorescence centered at around 520 nm, which is characteristic for monomeric Pt^II complexes. In stark contrast, the single‐crystal X‐ray structure determination of [Pt(C4pz)₂] ( 1 ) shows the formation of a dimeric aggregate with a notable Pt???Pt contact of 3.258 Å. Upon heating, all Pt^II complexes 1 – 4 melted to form columnar suprastructures, for which similar intracolumnar Pt???Pt distances of approx. 3.4–3.5 Å are observed within an exceptionally wide temperature range (>250 °C), according to the powder XRD data. Upon casting into a neat thin film at RT, the luminescence of 1 – 4 is dominated by a red emission that spans 630–660 nm, which originates from the one‐dimensional, chainlike structure with Pt–Pt interaction in the ground state. Taking complex 4 as a representative, the emission intensity and wavelength were significantly decreased and blueshifted, respectively, on heating from RT to 250 °C. Further heating to liquefy the sample alters the red emission back to the green phosphorescence of the monomer. The results highlight the pivotal role of tris(alkoxy)phenyl groups in the structural versus luminescence behavior of these Pt^II complexes.     

Facile fabrication of anatase TiO2 microspheres on solid substrates and surface crystal facet transformation from {001} to {101}

Anatase TiO(2) microspheres with controlled surface morphologies and exposed crystal facets were directly synthesized on metal titanium foil substrates by means of a facile, one-pot hydrothermal method without use of any templating reagent. The obtained products were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelecron spectroscopy (XPS), and the focused ion beam (FIB) technique. The sizes of the resultant microspheres ranged from 1.1 to 2.1 μm. The transformation of anatase TiO(2) microspheres with exposed {001} facets surface to nanosheets surface with {101} facets was achieved by simply controlling the hydrothermal reaction time. The anatase TiO(2) microspheres with exposed square-shaped plane {001} facets were obtained by controlling the reaction time at 1 h. The prolonged reaction time transforms the anatase TiO(2) microspheres with exposed square-shaped plane {001} facets to eroded {001} facets then to a nanosheet surface with exposed {101} facets. With hydrothermal synthesis, the surface morphological structure and crystal facets formation are highly dependent on dissolution/deposition processes, which can be strongly influenced by attributes, such as pH of the reaction media, the total concentration of dissolved and suspended titanium species, and the concentration of fluoride in the reaction solution. The changes of these attributes during the hydrothermal process were therefore measured and used to illustrate the morphology and crystal-facet transformation processes of anatase TiO(2) microspheres. The surface morphologies and crystal-facet transformations during hydrothermal processes were found to be governed by the compositional changes of the reaction media, driven by dynamically shifted dissolution/deposition equilibria. The photocatalytic activities of the photoanodes made of anatase TiO(2) microspheres were evaluated. The experimental results demonstrated that the photocatalytic activity of anatase TiO(2) microspheres with exposed {001} facets was found to be 1.5 times higher than that of the anatase TiO(2) microspheres with exposed {101} facets.     

Synthesis, structure, and reactivity of a pyridine-stabilized germanone

The first isolable pyridine‐stabilized germanone has been prepared and its reactivity toward trimethylaluminum has been investigated. The germanone adduct results from a stepwise conversion that starts from 4‐dimethylaminopyridine (DMAP) and the ylide‐like N‐heterocyclic germylene LGe: (L=CH{(C?CH₂)(CMe)[N(aryl)]₂}, aryl=2,6‐iPr₂C₆H₃) ( 1 ) at room temperature, and gives the corresponding germylene–pyridine adduct L(DMAP)Ge: ( 2 ) in 91 % yield. The latter reacts with N₂O at room temperature to form the desired germanone complex L(DMAP)Ge?O ( 3 ) in 73 % yield. The Ge? O distance of 1.646(2) Å in 3 is the shortest hitherto reported for a Ge?O species. The reaction of 3 with trimethylaluminum leads solely to the addition product LGe(Me)O[Al(DMAP)Me₂] ( 4 ). The latter results from insertion of the Ge?O subunit into an Al? Me bond of AlMe₃ and concomitant migration of the DMAP ligand from germanium to the aluminum atom. Compounds 2 – 4 have been fully characterized by analytical and spectroscopic methods. Their molecular structures have been established by single‐crystal X‐ray crystallographic analysis.     

4GPa超高压凝固Mg-6Zn-3Y合金的凝固组织及相分析

利用X射线衍射仪、扫描电镜并配合能谱分析研究了Mg-6Zn-3Y合金4 GPa超高压凝固组织.结果表明:在4 GPa超高压条件下凝固时,实验合金的凝固组织得到显著细化,基体α-Mg相的晶格间距有所减小;Zn在基体α-Mg中溶解度大幅提高,Y不溶于基体α-Mg;实验合金凝固组织中出现呈对称性的四瓣或六瓣花的初晶Y固溶体,该初晶花瓣形貌完整、尺寸较大,显示其充分自由生长;先发生的共晶反应的共晶组织为成“簇”分布的共晶团,共晶相呈点状或棒状;后发生的共晶反应的组织为离异共晶.超高压凝固显著地改变了实验合金的凝固过程.