161 resultados para 2,4-Dinitrophenol


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Reactions of the Rh hydrido complex [Rh(H)(2)(PPh3)(2)(EtOH)(2)]ClO4 (1) With nitrogen ligands such as 2-(4-thiazolyl)benzimidazole (tbz). pyridazine (pdz), imidazole (im) and pyrimidine (pmd) in CH,Cl, afforded Various mononuclear Rh hydrido complexes, [Rh(H)(2)(PPh3)(2)(tbz)]CIO4 (2), [Rh(H)(2)(PPh3)(2)(pdZ)(2)]ClO(4)(.)2CH(2)Cl(2) (3). [Rh(H)Cl(PPh3)(2)(pdz)(2)](ClO4CH2Cl2)-C-. (4). [Rh(H)(2)(PPh3)(2)(im)(2)]ClO(4)(.)2CH(2)Cl(2) (5). [Rh(H)Cl(PPh3)(2)(im)(2)](ClO4CH2Cl2)-C-. (6). [Rh(H)(2)(PPh3)(2)(pmd)(2)](ClO4CH2Cl2)-C-. (7) and the Rh non-hydrido complex [RhCl2(pmd)(4)]ClO4 (8). The Rh complexes 2. 3, 5 and 6 were crystallographically characterized. The formation process was monitored by H-1 NMR and UV-Vis spectra. In all the Rh hydrido complexes, the Rh atom is coordinated by two PPh3. ligands in trans-positions and two nitrogen ligands in the cis-positions. The remaining sites Lire occupied by one or two hydride atoms to form a saturated 18-electron framework in a slightly distorted octahedral geometry. For complex 2 an appreciable inter-molecular pi interaction is observed between planes of tbz and PPh3 ligands, while an intra-molecular hydrogen bonding interaction between C-H and Cl atoms is found in complex 6.

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A novel compound [Ni(phen)(3)](2)[(SiMo10V1/2O40)-O-V((VO)-O-IV)(2)] . 2H(2)O has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. The compound crystallizes in the triclinic, system, space group P-1, a = 12.378(4) Angstrom, b = 14.148(5) Angstrom, c = 14.316(2) Angstrom, alpha = 105.91(2)degrees, beta = 95.31(2)degrees, gamma = 96.89(3)degrees, V = 2373.0(12) Angstrom(3), Z = 1, (lambdaMo(Kalpha)) = 0.71073 Angstrom, R1 (wR2) = 0.0869(0.2174). Data were collected on a Siemens P4 four-circle diffractometer at 293 K in the range of 1.51 < theta < 22.50degrees using the omega-scan technique. Empirical absorption correction (psi scan) was applied. The structure was solved by the direct method and refined by the Full-matrix least-squares on F-2 using the SHELXL-97 software. X-ray crystallographic study showed that the title compound contained a bi-capped alpha-Kegin-type [(SiMo10V2O40)-O-IV((VO)-O-IV)(2)](4-) polyoxoanion.

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Co2 (CO) 8 与 4个二硫代双 (烷基硫代甲酰胺 )类前配体 [R2 NC(S) S]2 反应 ,得 4个含烷基硫代甲酰胺基的三核钴羰基硫簇合物 .通过元素分析、IR、 1H NMR和 MS等方法表征了它们的结构 ,用 X射线衍射法测定了其中一个簇合物 Co3 (CO) 7(μ3 - S) [μ,η2 - SCN(i- Pr) 2 ]( )的晶体结构 .晶体属单斜晶系 ,P2 1/n空间群 ,晶胞参数 a=1.1452 (2 ) nm,b=1.50 2 8(3) nm,c=1.2 144 (2 ) nm,α=90°,β =92 .15(3)°,γ =90°,V =2 .0 885(7) nm3 ,Z=4 ,F (0 0 0 ) =10 96 ,Dc=1.74 7mg· m-3 ,GOF(F2 ) =0 .835,μ=2 .588nm-1.最终因子 R[I>2 σ(I) ]=0 . 0 4 0 7,Rw=0 .0 6 2 4

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Sixteen novel beta-alkoxycarbonylethyltin trichlorides and the corresponding N-aryl-2-hydroxyacetophenylideneimines complexes have been synthesized and characterized. An X-ray crystal structure analysis of the complex of beta-methyloxycarbonylethyltin trichloride and N-4-methylphenyl-2-hydroxyacetophenylideneimine has been performed, The crystal belongs to space group , The cell parameters are: a = 1.0201(6) nm, b = 1.082 2(4) nm, c = 1.394 9(6) nm, alpha = 99.88(3)degrees, beta = 98.63(4)degrees, gamma = 97.86(4)degrees, Z = 2, The ligands coordinate to tin atom via phenolic oxygen atom. Coordination of carbonyl oxygen atom to tin atom still exists in the complexes, The coordination number of tin atom is 6.

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catena-Poly[{pentaaqua(L-proline-O)-erbium-mu-(L-proline-O:O')} trichloride], {[Er(C5H9-NO2)2(H2O)5]Cl3}n, M(r) = 594.0, monoclinic, P2(1), a = 8.294 (1), b = 10.981 (3), c = 11.934 (3) angstrom, beta = 107.04 (2)degrees, V = 1039.2 (4) angstrom3, Z = 2, D(x) = 1.90 g cm-3, lambda(Mo Kalpha) = 0.71069 angstrom, mu = 45.2 cm-1, F(000) = 586, T = 298 K, R = 0.0244 for 1711 unique reflections [I > 3 sigma(I(o))]. The crystal consists of one-dimensional chains of infinite length in which one L-proline ligand bridges two neighboring Er ions, the other L-proline ligand being monodentate.

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三-(2-甲基氮丙啶)氧化膦(MAPO)为黄色油状液体,其化学性质活泼,可用作塑料、橡胶及造纸业中高分子化合物的交联剂等。本文对MAPO进行了~1H、~(13)C、~(15)N、~(31)P和~(17)O的核磁共振研究及量子化学计算。结果表明,该化合物存在4种异构体,其中2种为对映体,并得到了这4种异构体的几何构型。

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The monolayer and deposition behaviour of a symmetrically substituted copper tetra-4-(2, 4-di-t-amylphenoxy) phthalocyanine (tapCuPc) and an asymmetrically substituted copper [tri-4-(2, 4-di-t-amylphenoxy)-mono-4-(-2-methoxyethoxy)]phthalocyanine (AsyCuPc) were investigated. The results on monolayer behaviour and spectroscopic characterization of the LB films show that both CuPc molecules in a monolayer at the air-water interface and the LB films are stacked and inclined. The gas-sensitive properties show that the responding speed of AsyCuPc LB film is faster than that of tapCuPc LB film.

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从患病牙鲆中分离出迟缓爱德华氏菌株TX1,经报告菌株检测发现TX1有AI-2活性。用梯度PCR和Genome walking的方法克隆了TX1 luxS基因,将luxS基因在大肠杆菌DH5α中表达,证明其具有功能活性。在TX1中,luxS的表达与AI-2的活性基本是一致的,二者均受生长时期和生长条件的调节,即在glucose存在的条件下luxS表达和AI-2活性升高,而在高温条件下luxS表达和AI-2活性降低。glucose对AI-2活性以及luxS表达的影响经过荧光定量PCR,启动子活性检测,AI-2活性检测以及凝胶滞缓等一系列的实验证实是由cAMP-CRP复合物介导的,该复合物可以通过与luxS启动子相互作用而抑制luxS的表达。RNA干扰表明,TX1中luxS表达被干扰以后,对细菌产生了多方面的影响,包括:(1) 降低AI-2水平;(2) 降低细菌的生长能力;(3) 降低Ⅲ型分泌系统相关基因的表达水平以及生物膜的形成能力;(4) 减弱细菌毒力。外源AI-2的添加可以回复Ⅲ型分泌系统相关基因的表达水平以及生物膜的形成,但是并不能修复生长状况,表明LuxS在TX1中具有双重功能,即参与细胞代谢以及群体感应信号传导。基于LuxS/AI-2群体感应系统对细菌毒力的重要性,设计并筛选了一个该系统的阻遏因子5411。Pull-down实验证明5411可以和LuxS特异性结合。研究表明5411在TX1中表达导致细菌毒力显著下降。将5411克隆至牙鲆共生菌FP3中,发现5411可以被分泌到胞外并能被TX1吸收。将表达5411的共生菌导入牙鲆,发现其能够有效阻遏TX1对牙鲆的侵染。 这些结果表明:(1) TX1中AI-2的活性受控于LuxS,而后者则受生长时期和生长条件的调控;(2) luxS的正常表达对于细菌的正常生长和侵染是必需的;(3) LuxS/AI-2群体感应系统调控Ⅲ型分泌系统相关毒力因子的表达;(4) 通过阻遏LuxS/AI-2群体感应系统来抑制病原菌侵染是一种具有潜力的新型病害防控方法。

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情绪表达规则是指一个人应当在恰当的情境中表达恰当的情绪。对情绪表达规则的认知发展是个体社会能力发展的一个重要方面,因此这一主题引起了国内外众多研究者的重视。但目前对童年早期儿童的研究中,大多数只考查了儿童对情绪的外显表达与内隐真实体验的区分,没有同时考查儿童对需要使用情绪表达规则的情境的认知,不能全面真实地揭示儿童对情绪表达规则的认知发展。在本研究中,以个别访谈法考查了4-6岁儿童同一个体在这两个指标上对情绪表达规则认知的发展,以及发展中的个别差异和个体内部差异,并进一步了解情境因素以及心理理论能力、执行抑制能力的发展对它们的影响。主要结果如下: (1)4-6岁儿童对情绪表达规则的认知能力随年龄增长而提高:4岁尚处于发展的萌芽水平,5岁和6岁都处于发展的过渡水平。对于同一年龄的儿童,对情绪表达规则的认知发展存在较大的个体之间的差异。 (2)4-6岁儿童对情绪表达规则的认知也存在较大的个体内部差异:对表情伪装的认知滞后于对需要使用情绪表达规则的情境的认知,对言语伪装的认知优于对表情伪装的认知;在对情绪表达规则的使用中,自我定向的占多数,其次是他人定向,规则定向所占的比例最少。随年龄的增长,自我定向的比例减少,他人定向的比例增多。 (3)情境变量影响4-6岁儿童对情绪表达规则的认知:与同伴交往情境中对需要使用情绪表达规则的情境的认知、对言语伪装的认知优于与长辈交往情境中的有关认知;对需要掩藏消极情绪情境中对表情伪装的认知要优于对需要掩藏积极情绪情境中表情伪装的认知。 (4)4-6岁儿童心理理论能力的发展和执行抑制能力的发展与其对情绪表达规则的认知发展有关。 (5)有关情绪表达规则的提示能够促进儿童对情绪隐私的认知,促进的效果随年龄的增长而提高,6岁的效果最好。

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2-(9-Carbazole)-ethyl-chloroformate (CEOC), a novel pre-column fluorescence labeling reagent, has been synthesized and applied for the derivatization of phenols. Taken phenol, p-chlorophenol, 2,5-dimethylphenol, 2,4-dichlorophenol and 1,4-dihydroxybenzene as testing standards, the effects of derivatization conditions, such as pH of borate buffer, reaction time and fluorescent tagging reagent concentration, have been systematically studied. Under the optimized conditions, CEOC reacts readily with the phenols to form stable derivatives with excitation and emission wavelengths, respectively, at 293 and 360 nm. The single step derivatization reaction could be finished within 20 min even at room temperature. Such a method has been successfully applied to the analysis of phenols in printing ink by high-performance liquid chromatography. (c) 2005 Elsevier B.V. All rights reserved.