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171.
HuaRongZHAO XiaoFengLI XinJianZHAO YangPingNIU 《中国化学快报》2004,15(11):1292-1294
Aryl selenoamides react smoothly with a-haloacetic acid in various alcohol to givecorresponding bis(carboxyalkylmethyl) diselenides in good yields. 相似文献
172.
O/W微乳液中聚吡咯超微粒子的制备 总被引:4,自引:0,他引:4
选择合适的SDBS/吡咯/H2O三组分O/W微乳液与吡咯单体共存的两相体系,以单体相为单体源,在O/W三组分微乳液中进行了吡咯聚合,所得聚吡咯粒子大小仅为2~3nm,分布较均匀,且具有较好的导电性能. 相似文献
173.
高效阳离子交换法分离纯化蛋清中的溶菌酶 总被引:3,自引:0,他引:3
建立了用高效阳离子交换分离纯化蛋清中溶菌酶的新方法 ,讨论了纯化的工艺条件。蛋清样品匀浆后 ,用氯化钠初步纯化 ,然后用弱阳离子交换柱XIDACE WCX分离。结果表明 ,被纯化的溶菌酶和杂蛋白得到很好分离。经活性检测 ,溶菌酶过柱后的活性回收率为 10 7% ,蛋白的比活为 15 4 6 7U/mg ,纯化倍数提高了 5 6倍。用尺寸排阻 (SEC)鉴定 ,得到的溶菌酶呈均一性。该法较传统软基质低压离子交换分离速度快 ,纯化效率高。 相似文献
174.
Reaction of PdCl2(CH3CN)2 with the sodium salt of 5‐mercapto‐1‐methyltetrazole (MetzSNa) in methanol solution affords an interesting dinuclear palladium complex [Pd2(MetzS)4 ] ( 1 ). However, treatment of PdCl2(CH3CN)2 with neutral MetzSH ligand in methanol solution produces a mononuclear palladium complex [Pd(MetzSH)4]Cl2 ( 2 ). Both complexes were characterized by IR, 1HNMR, UV‐Vis spectroscopy as well as X‐ray crystallography. Single‐crystal X‐ray diffraction analyses of two complexes lead to the elucidation of the structures and show that 1 possesses an asymmetric structure: one Pd atom is tetracoordinated by three sulfur atoms and one nitrogen atom to form PdS3N coordination sphere, the other Pd atom is tetracoordinated by three nitrogen atoms and one sulfur atom to form PdSN3 coordination sphere. The molecules of 1 are associated to 1‐D infinite linear chain by weak intermolecular Pd···S contacts in the crystal lattice. In 2 , the Pd atom lies on an inversion center and has a square‐planar coordination involving the S atoms from four MetzSH ligands. The two chloride ions are not involved in coordination, but are engaged in hydrogen bonding. 相似文献
175.
Yiru Zhang Jianlei Shen Rong Hu Xiujuan Shi Xianglong Hu Benzhao He Anjun Qin Ben Zhong Tang 《Chemical science》2020,11(15):3931
Surface immobilization provides a useful platform for biosensing, drug screening, tissue engineering and other chemical and biological applications. However, some of the used reactions are inefficient and/or complicated, limiting their applications in immobilization. Herein, we use a spontaneous and catalyst-free amino-yne click bioconjugation to generate activated ethynyl group functionalized surfaces for fast immobilization of native proteins and cells. Biomolecules, such as bovine serum albumin (BSA), human IgG and a peptide of C(RGDfK), could be covalently immobilized on the surfaces in as short as 30 min. Notably, the bioactivity of the anchored biomolecules remains intact, which is verified by efficiently capturing target antibodies and cells from the bulk solutions. This strategy represents an alternative for highly efficient surface biofunctionalization.Fast surface immobilization of native bioconjugates through a spontaneous amino-yne click reaction is realized. 相似文献
176.
The complex Eu(btfa)3 (phen) (btfa=4,4,4‐trifluoro‐1‐phenyl‐1, 3‐butanedione, phen = 1,10‐phenanthroline) has been prepared and characterized by elemental analysis, IR and UV spectroscopies. The crystal and molecular structures of the complex have been determined by X‐ray diffraction analysis. It belongs to the monoclinic crystal system, space group P21/c with a = 0.9700(2) nm, b = 3.7450(5) nm, c = 1.0917(3) nm, β = 92.51(2)°, V = 3.962(1) nm5, Z = 4, Dc = 1.639 g/cm3, μ = 1.676 mm?1, F(000) = 1936, R1, = 0.0388, wR2 = 0.0775. Structure analysis shows that the europium(III) ion is coordinated to six oxygen atoms of β‐diketonate anions and two nitrogen atoms of phenanthroline molecule. The coordination polyhedron is an approximate square antiprism. 相似文献
177.
Jian Yan Xiang‐Ming Zhang Zhong‐Rong Li Lin Zhou Jian‐Chao Chen Li‐Rong Sun Ming‐Hua Qiu 《Helvetica chimica acta》2005,88(2):240-244
Three new triterpenoids, (3β,8β,14α,21α)‐26,27‐dinoronocerane‐3,8,14,21‐tetrol ( 1 ), (3β,8β,14α,21β)‐26,27‐dinoronocerane‐3,8,14,21‐tetrol ( 2 ), and lycopodiin A ( 3 ), together with four known compounds, lycoclavanol ( 4 ), lycoclaninol ( 5 ), α‐onocerin ( 6 ), and 3‐epilycoclavanol ( 7 ), were isolated from Lycopodium japonicum Thunb (Lycopodiaceae). Their structures were established by means of spectroscopic analyses. Compounds 3 and 7 showed moderate antitumor activity. Compounds 4 and 6 exhibited acetylcholinesterase inhibition activity. 相似文献
178.
以紫外光谱法研究了青霉素G钾盐(Pen-K)在十六烷基三甲基溴化铵(CTAB)胶束体系中的水解反应, 并探讨了水解反应机理.结果表明, CTAB胶束对Pen-K的水解具有抑制作用; Pen-K在CTAB胶束体系水解时,体系pH值的变化与在水中相似, 表明H+浓度对这种抑制作用影响较小.红外光谱和微极性研究表明,部分Pen-K钾盐定位于CTAB胶束栅栏层中, 增加了其稳定性. 相似文献
179.
HU Rong TIAN Jinping & YIN Yingwu . College of Chemistry & Environment Protection Engineering Southwest University for Nationalities Chengdu China . TH-UNIS Insight Co. Ltd. Beijing China . Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology Ministry of Education Department of Chemistry Tsinghua University Beijing China 《中国科学B辑(英文版)》2006,49(4):351-356
The formation of peptides and then protein by small abiological molecules clusters such as amino acid is a key stage in the origin of life[1]. More and more ex- perimental results showed that phosphate plays an important role in the formation of biomolecules in prebiotic chemical evolution. The principal reservoirs of biochemical energy are phosphates (such as ATP). The peculiar role of phosphates in contemporary life might suggest its essential role in prebiotic energy conversion, syntheses … 相似文献
180.
Ching Hsuan Lin Zheng Rong Jiang Chun Shan Wang 《Journal of polymer science. Part A, Polymer chemistry》2002,40(22):4084-4097
A 2,6‐dimethyl phenol–dipentene adduct was synthesized from dipentene (DP) and 2,6‐dimethyl phenol, and then a 2,6‐dimethyl phenol–DP epoxy was synthesized from the reaction of the resultant 2,6‐dimethyl phenol–DP adduct and epichlorohydrin. The proposed structures were confirmed by Fourier transform infrared, elemental analysis, mass spectra, NMR spectra, and epoxy equivalent weight titration. The synthesized 2,6‐dimethyl phenol–DP adduct was cured with 4,4‐diamino diphenyl methane, phenol novolac, 4,4‐diamino diphenyl sulfone, and 4,4‐diamino diphenyl ether. The thermal properties of the cured epoxy resins were studied with differential scanning calorimetry, dynamic mechanical analysis, dielectric analysis, and thermogravimetric analysis. These data were compared with those for the bisphenol A epoxy system. The cured 2,6‐dimethyl phenol–DP epoxy exhibited a lower dielectric constant (ca. 3.1), a lower dissipation factor (ca. 0.065), a lower modulus, lower thermal stability (5% degradation temperature = 366–424 °C), and lower moisture absorption (1.21–2.18%) than the bisphenol A system but a higher glass‐transition temperature (ca. 173–222 °C) than that of bisphenol A system. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4084–4097, 2002 相似文献