共查询到20条相似文献,搜索用时 31 毫秒
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镉(Ⅱ)-1-苯基-3-甲基-4-苯甲酰基-吡唑啉酮-5配合物吸附波的研究 总被引:1,自引:0,他引:1
在pH4.8的HAc-NH_(4)Ac介质中,Cd(Ⅱ)与1-苯基-3-甲基-4-苯甲酰基-吡唑啉酮-5(PMBP)生成配合物,于-0.67V(vs.SCE)出现一尖锐、灵敏的极谱波。镉含量在0.001~1.μg/mL范围内与峰高成线性关系。用多种电化学方法研究了极谱波的性质及电极反应机理,证明-0.67V处的极谱波为配合物吸附波,峰电流由中心离子Cd(Ⅱ)还原产生。配合物组成为Cd(Ⅱ):PMBP=1:1。试验了30多种离子对峰电流的影响,用SrSO_4共沉淀分离Pb(Ⅱ),再经巯基棉分离其它干扰离子。用于矿样中镉的测定,结果满意。 相似文献
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用pH法在25.0±0.1℃、I=0.1mol/LKNO3条件下研究了铜(Ⅱ)与12-(2'-羟基-5取代苄基)-1,4,7,10-四氮杂环十三烷-11,13-二酮-α-氨基酸所形成的竞争性三元混配型配合物的稳定性,测定了该体系的二元、三元配合物的稳定常数,并探讨了大环配体的取代基效应及二元、三元配合物的结构。 相似文献
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在非水溶剂中合成了苯并-15-冠-5与碘化钾、硫氰化钾及苦味酸钾形成的三种新型固体配合物,并进行了有关物理、化学性质表征.结果表明,钾(Ⅰ)离子不仅易与苯并-15-冠-5形成常见的1:2夹心式配合物,而且还能生成稳定的1:1型固体配合物. 相似文献
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铒-谷氨酸配合物的晶体结构及表征 总被引:1,自引:0,他引:1
合成了铒与L-谷氨酸形成的配合物[Er_2(L-Glu)_2·(H_2O)_8](ClO_4)_4.3H_2O,由元素分析、红外光谱、热分析对配合物进行了麦征。得到了配合物的单晶,该晶体属于单斜晶系,空间群P2_1,晶胞参数a=19987(3)nm,b=16505(3)nm,c=1.1040(2)nm,β=104(1),V=3.538nm ̄3,Z=2,R=0.043。晶体结构中每一个独立区含有二个晶体学上独立的配合物分子,每个配合物分子含有两个中心离子,它们之间通过二个桥式羧基和二个螯合三齿羧基相连接,中心离子的配位数为9。 相似文献
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Yeganeh Khaniani Hamid Golchoubian 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2817-2823
A convenient method for the preparation of the phenol-based ligands 1,6-bis(2-thiophenyl)-2,5-bis(2-hydroxy-3-hydroxymethyl-5-methylbenzyl)-2,5-diazahexane and 1,6-bis(5-methyl-2-thiophenyl)-2,5-bis(2-hydroxy-3-hydroxymethyl-5-methyl-benzyl)-2,5-diazahexane possessing two dissimilar compartments having multifunctional groups is reported. To synthesize these ligands, an equivalent of 1,6-bis(2-thiophene)-2,5-diazahexane or 1,6-bis(5-methyl-2-thiophene)-2,5-diazahexane and two equivalents of 2,2-dimethyl-6-methyl-8-(chloromethyl)benzo-1,3-dioxin were reacted in the presence of Na2CO3 in 1,4-dioxane, followed by acid hydrolysis of an acetonide-protecting group. Characterization data for the new compounds is reported. 相似文献
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高植生 《高等学校化学学报》1988,9(5):513
我们认为,如金属离子M能与配位体A和B形成二元络合物,那么在配位数允许和不存在空间障碍的情况下,总有三元络合物形成.但由于两种配位体之间的浓度比例调节不当,会造成三元络合物在溶液里的所有组份中占很小的比例,这样,往往给人们一个错觉,即没有三元络合物形成,三元混配络合物在溶液里所有组份中所占的比例达到极大时,两配位体之间的浓度比例是可以通过计算得到的。 相似文献
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考察了双亚磷酸酯配体Bisphosphite 1、Bisphosphite 2及双膦配体DPPE、DPPP、DPPB、BISBI在丁烯氢甲酰化反应中的反应活性和选择性,并对双亚磷酸酯配体和双膦配体进行混合,应用到丁烯氢甲酰化反应当中,对混合配体进行筛选发现Bisphosphite 1与DPPB混合配体的反应效果最佳,明显提高了1-丁烯氢甲酰化产物醛的正异构比,并通过31P NMR等方法推测了混合配体与铑配位的关键配合物中间体.通过正交实验优选了铑催化剂浓度、Bisphosphite 1浓度与DPPB浓度,其优化的催化剂配方对1-丁烯氢甲酰化的正异构比达到76.3,平均TOF 1821 h-1. 相似文献
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考察了双亚磷酸酯配体Biphephos及双膦配体DPPE、DPPP、DPPB、BISBI在丁烯氢甲酰化反应中的反应活性和选择性,并对双亚磷酸酯配体和双膦配体进行组合,应用到丁烯氢甲酰化反应当中,对组合配体进行筛选发现Biphephos与DPPB组合配体的反应效果最佳,明显提高了产物醛的正异构比。通过正交实验进一步优选了铑催化剂浓度、Biphephos浓度与DPPB浓度,其优化的催化剂配方的正异构比达到76.3,平均TOF1821h-1。 相似文献
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In this paper, the design and synthesis of a new indazole bearing a photoisomerizable fragment at its 4-position are presented as well as the photoisomerization studies on both the indazole precursor and the final ruthenium model complex. It was obtained after five steps, the last one being the cleavage of the indazole protecting group. Reaction of 1 equiv of this functionalized indazole with 2 equiv of plain indazole and dibromophenylborane gave access to a mixture of four tripodal ligands of the tris(indazolyl)borate family. In a last step, complexation of this mixture with [RuCp(CH3CN)3]PF6 yielded the corresponding ruthenium complexes from which the target ruthenium complex coordinated to a dissymmetric azobenzene-functionalized tripodal ligand was successfully isolated. Photoisomerization occured reversibly upon irradiation with UV light at 365 nm. 相似文献
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The reaction of equimolar amounts of [Co(CO)3(NO)] and [PPN]CN, PPN+ = (PPh3)2N+, in THF at room temperature resulted in ligand substitution of a carbonyl towards the cyanido ligand presumably affording the complex salt PPN[Co(CO)2(NO)(CN)] as a reactive intermediate species which could not be isolated. Applying the synthetic protocol using the nitrosyl carbonyl in excess, the title reaction afforded unexpectedly the novel complex salt PPN[Co2(μ-CN)(CO)4(NO)2] ( 1 ) in high yield. Because of many disorder phenomena in crystals of 1 the corresponding NBu4+ salt of 1 has been prepared and the molecular structure of the dinuclear metal core in NnBu4[Co2(μ-CN)(CO)4(NO)2] ( 2 ) was determined by X-ray crystal diffraction in a more satisfactory manner. In contrast to the former result, the reaction of [PPN]SCN with [Co(CO)3(NO)] yielded the mononuclear complex salt PPN[Co(CO)2(NO)(SCN-κN)] ( 3 ) in good yield whose molecular structure in the solid was even determined and its composition additionally confirmed by spectroscopic means. 相似文献
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手性磷-烯配体在不对称催化反应中的应用近年来受到化学家们的关注,已经成为一个热门的研究领域.磷-烯配体作为一类新兴杂化烯烃配体,将具有强配位能力的磷原子与配位方式特殊但配位能力相对较弱的碳-碳双键结合在一起,兼具了部分手性膦配体和手性双烯配体的优点,在一些过渡金属如铑、钯、铱等催化的不对称反应中表现出独特的催化性能,不但能高效催化反应,而且能取得优异的对映选择性.本文综述了自2004年首例磷-烯配体的合成及应用报道以来该领域的研究进展,对过去十几年中发展的各种手性磷-烯配体的结构特征、合成方法以及它们在不同催化不对称反应中的应用进行了分类概括,期望为未来进一步拓展手性烯烃配体的类型和应用提供思考和方向. 相似文献
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Satoshi Haneda 《Tetrahedron》2009,65(50):10459-5595
CuI-2-(2′-pyridyl)benzimidazole catalyst system can serve efficiently to promote N-arylation of various indoles to afford the N-arylated indoles. The bidentate ligand, 2-(2′-pyridyl)benzimidazole was proved superior to monodentate nitrogen-based ligands and well-known bidentate ligands such as 2,2′-bipyridyl and 1,10-phenanthroline. 相似文献
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The reactions of trans-[MoO(ONOMe)Cl2] 1 (ONOMe = methylamino-N,N-bis(2-methylene-4,6-dimethylphenolate) dianion) and trans-[MoO(ONOtBu)Cl2] 2 (ONOtBu = methylamino-N,N-bis(2-methylene-4-methyl-6-tert-butylphenolate) dianion) with PhNCO afforded new imido molybdenum complexes trans-[Mo(NPh)(ONOMe)Cl2] 3 and trans-[Mo(NPh)(ONOtBu)Cl2] 4, respectively. As analogous oxotungsten starting materials did not show similar reactivity, corresponding imido tungsten complexes were prepared by the reaction between [W(NPh)Cl4] with aminobis(phenol)s. These reactions yielded cis- and trans-isomers of dichloro complexes [W(NPh)(ONOMe)Cl2] 5 and [W(NPh)(ONOtBu)Cl2] 6, respectively. The molecular structures of 4, cis-6 and trans-6 were verified by X-ray crystallography. Organosubstituted imido tungsten(VI) complex cis-[W(NPh)(ONOtBu)Me2] 7 was prepared by the transmetallation reaction of 6 (either cis or trans isomer) with methyl magnesium iodide. 相似文献