二-(4-溴-2,5-二烷氧基苯基)甲烷及其类似物的合成

报道二-(4-溴-2,5-二烷氧基苯基)甲烷的一种简便合成方法.1,4-二乙氧基-2,5-二(烷氧基甲基)苯(1)在对甲苯磺酸催化下生成柱形杯[5]芳烃化合物2;2与N-溴代丁二酰亚胺(NBS)反应,生成二-(4-溴-2,5-二烷氧基苯基)甲烷(3).该方法反应条件温和、操作简单、选择性好、收率高.2与硝酸发生硝化反应,生成二-(4-硝基-2,5-二甲氧基苯基)甲烷(4).所合成的二-(4-溴-2,5-二烷氧基苯基)甲烷和二-(4-硝基-2,5-二甲氧基苯基)甲烷经过1H NMR,13C NMR和MS表征确认.     

Fluorescence enhancement of cationic diacetylene‐contained polyelectrolyte by anions and cations and application for sensitive and selective detection of Hg2+

An unusual phenomenon, the fluorescence enhancement of cationic conjugated fluorene‐co‐carbazole‐co‐diacetylene polymers (CPFC) by both anionic and cationic ions, was reported. The fluorescence enhancement of CPFC strongly depended on the nature of the ions and the counterions. In the solution of DMF/H₂O, PO, CO and Hg²⁺ showed the most pronounced fluorescence enhancement response of CPFC (more than 10‐fold). The fluorescence of CPFC was quenched by K₄[Fe(CN)₆, and then could be recovered with the addition of Hg²⁺. Based on these observations, a simple and sensitive fluorescent “turn‐on” sensor in aqueous solution for Hg²⁺ was developed by use of a system of CPFC/ K₄[Fe(CN)₆]. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011     

Synthesis of double D–A branched organic dyes employing indole and phenoxazine as donors for efficient DSSCs

Four novel metal-free organic sensitizers bearing double donor–acceptor (D–A) branches with indole and phenoxazine units as donors (SDD1–4) and cyanoacrylic acid as electron acceptor were synthesized and characterized for dye-sensitized solar cells (DSSCs). Dyes SDD1–3 were designed with indole as a donor and 1,4-phenylenebis(methylene), 1,4-butylene and 1,6-hexylene as a linker, respectively, while the dye SDD4 was designed with phenoxazine as a core donor. Their photophysical, electrochemical, and DSSCs characteristics were investigated. The results show that the architecture structure of the linkage affects the performance of the cells slightly. The DSSCs based on SDD4 shows much higher η than the DSSCs based on SDD1–3, which indicated that phenoxazine is a better donor than indole. Under standard global AM 1.5 solar condition (100 mW cm⁻²), the SDD4 dye-sensitized cell gave the highest η of 4.33% with chenodeoxycholic acid as a coadsorbent, reaching 82% of N719-based DSSCs.     

一类有限阶可解完全群

设G是一个群。如果 那么G就称为一个完全群。Hlder曾经证明,对任意整数n≥3,n≠6,对称群S_n是完全群。Wielandt证明,任何一个有限非交换单群的自同构群是完全群。但除S_3和S_4之外,这些有限完全群都不是可解的。本文中,我们将给出一类有限阶可解完全群。为此目的,我们设p为任意素数,并用G_(np)表示素域F_p上一切形如     

Syntheses,characterization and biological studies of zinc(II), copper(II) and cobalt(II) complexes with Schiff base ligand derived from 2‐hydroxy‐1‐naphthaldehyde and selenomethionine

Novel zinc(II), copper(II), and cobalt(II) complexes of the Schiff base derived from 2‐hydroxy‐1‐naphthaldehyde and D, L ‐selenomethionine were synthesized and characterized by elemental analysis, IR, electronic spectra, conductance measurements, magnetic measurements and powder XRD. The analytical data showed the composition of the metal complex to be ML(H₂O), where L is the Schiff base ligand and M = Co(II), Cu(II) and Zn(II). IR results confirmed the tridentate binding of the Schiff base ligand involving azomethine nitrogen, naphthol oxygen and carboxylato oxygen atoms. ¹H NMR spectral data of lithium salt of the Schiff base ligand [Li(HL)] and ZnL(H₂O) agreed with the proposed structures. The conductivity values of complexes between 12.50 and 15.45 S cm² mol^?1 in DMF suggested the presence of non‐electrolyte species. The powder XRD studies indicated that Co(II) complex is amorphous, whereas Cu(II) and Zn(II) complexes are crystalline. The results of antibacterial and antifungal screening studies indicated that Li(HL) and its metal complexes are active, but CuL(H₂O) is most active among them. Copyright © 2010 John Wiley & Sons, Ltd.     

Beam spot size evolution of Gaussian femtosecond pulses after angular dispersion

Beam spot size evolution of spatially Gaussian femtosecond laser pulses after angular dispersion is analyzed and verified with experiments. A general analytical expression for beam spot size at arbitrary propagation distances is obtained, which indicates that beam spot size evolution after angular dispersion is determined by the direct interaction of spectral lateral walk-off by angular dispersion and the intrinsic divergence of the Gaussian beam. This work reveals insights into the propagation of Gaussian femtosecond laser pulses and beams after angular dispersion and may be important for the generation and application of femtosecond laser pulses.     

Porous Cationic Covalent Triazine‐Based Frameworks as Platforms for Efficient CO2 and Iodine Capture

Porous cationic covalent triazine‐based frameworks (CTFs) with imidazolium salts as tectons were prepared via ionothermal synthesis. The high‐PF₆^?‐content CTF shows the CO₂ adsorption of 44.7 cm³ g^?1 and I₂ capture capacity of 312 wt %. The influence of counterion species and contents on the porosities, CO₂ adsorptions, and I₂ capture capacities of the CTFs has been investigated.     

侧链含芳香基的聚醚树脂的合成及其吸附性能研究

聚[B-氯乙基缩水甘油醚]分别和4-氨基偶氮苯,4-氨基-2”,3-二甲基偶氮苯、4-氨基-4”-氯联苯、4-羟偶基氮苯、4、4”-二氨基-3,3”二甲氧基联苯及1、3-二(4-羟基-苯基丙烷反应,合成了六种新型的聚醚树脂。它们对A_u(Ⅲ)等离子显示出较好的吸附选择性。     

聚γ-氨丙基硅氧烷钯、钼双金属催化剂的合成、加氢活性及其XPS研究

本工作合成了四种不同N/Pd摩尔比的聚γ-氨丙基硅氧烷钯、钼双金属催化剂,它们的加氢活性与相应的钯、钼单金属催化剂的混合物相比差别不大,但是,由于钼的加入,提高了单金属钯催化剂的加氢活性。XPS分析表明,有一部分N与PdCl_2及MoCl_x发生络合,而且Pd-Cl键和Mo—Cl键依然存在,催化剂中Pd的价态为正2价,Mo的价态为正5或6价。