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191.
192.
The coordination compounds of acctylacetonate-5,10,15,20-tctrasubstituted phcnyl-porphyrin with Yttrium, Y(o-Cl)Tppacac, Y(m- Cl)Tppacac, Y(p-Cl)Tppacac, Y(o-CH3O) Tppacac, and Y(p-CH3O)Tppacac (H2Tpp: tetraphcnylporphyrin, Hacac: acetylacctonc), were prepared and characterised on the basis of elemental analysis, infrared spectra, UV-visiblc spectra and thermal analysis. 相似文献
193.
不对称催化是由潜手性反应物合成光活性化合物的有效途径,α,β-不饱和氨基酸的氢化立体选择性已达90%以上,L-Dopa的工业化生产则标志着不对称催化氢化开始走向实际应用。高选择性的催化剂一般是一价铑的手性双膦配体络合物,其中DIOP[2,3-O-异丙叉- 相似文献
194.
采用密度泛函理论(DFT), 在B3LYP/6-311++G(d,p)基组上计算得到了21种N8H8链状异构体, 并研究了这些异构体间可能的互变异构情况. 为了得到更为精确的能量信息, 计算了QCISD(T)/6-311G(d,p)基组水平上各物质的能量. 所得的21种异构体分为4类(4种类型链状化合物): A为直链, B有一个支链, C有2个支链, D有3个支链; D类只有一种, A类稳定构型2种, B类稳定构型12种, C类稳定构型6种; 相对稳定的分别为: B2-1构型, B2-3构型和C23-2构型. 我们研究发现N8H8链状异构体中含有明显N=N双键特征有利于化合物稳定性的提高. 相似文献
195.
Tatsuya Oshima Masahiro Goto Shintaro Furusaki 《Journal of inclusion phenomena and macrocyclic chemistry》2002,43(1-2):77-86
A series of calixarene carboxylic acid derivatives were synthesized for the extraction of amino acids. A calix[6]arene carboxylic acid derivative showed the highest extractability to the target tryptophan ester. The main driving forcefor the complexation was the interaction between the ammonium cation of the aminoacid and the oxygen atoms of the host molecule. Stripping of amino acids was alsoaccomplished by contacting the organic solution with a fresh acidic solution. Basedon slope and Job method analyses, it was confirmed that the calix[6]arene formsa 1 : 1 complex with the amino acid ester. The structure of the complex between the calix[6]arene and the amino acid was investigated by 1H-NMR and CD spectra. The calix[6]arene includes a guest molecule in the cavity, and the inclusion induces the asymmetrization of the host molecule. This host compound functions as a novel recognition tool for amino acids. 相似文献
196.
LI Shu-Lan LIU De-Xin YANG Zhao-HeDepartment of Chemistry Shandong University Jinan Shandong China National Laboratory of Crystal Materials Shandong University Jinan Shandong China 《中国化学》1997,15(1):54-59
Monoaqua salicylaldehyde-o-aminobenzoic acid Ni(Ⅱ) monohydrate (cp1) and monoaqua o-vanillin-o-aminobenzoic acid Ni(Ⅱ) monohydrate (cp2) were synthesized. The composition and structures of these two compounds were analyzed. Their thermal stability and non-isothermal kinetics were also investigated by use of TG and DTG curves. The possible reaction mechanisms in their first steps of thermal decomposition reactions were deduced by means of integral and differential methods. Thermodecomposition kinetic equations of the compounds are as follows:Cp1: da/At = A . exp(-E/RT) . 3/2(1 - a)4/3 . [1/(1 - a)1/3 -1]-1 Cp2 : da/At = A . exp(-E/RT) . (1 - a) 相似文献
197.
Mit"kina T. V. Gerasko O. A. Sokolov M. N. Naumov D. Yu. Fedin V. P. 《Russian Chemical Bulletin》2004,53(1):80-85
Slow evaporation of hydrochloric acid solutions of zirconium(iv) or hafnium(iv) oxochlorides and cucurbituril in air afforded compounds with composition [M4(OH)8(H2O)16]Cl8·(C36H36N24O12)·16H2O, where M = Zr (1) or Hf (2). According to the X-ray diffraction data, complexes 1 and 2 are isostructural. Their crystal structures can be described as packings of polymer chains consisting of alternating cucurbituril molecules and tetranuclear cations [M4(OH)8(H2O)16]8+ linked to each other via an extensive network of hydrogen bonds. Compound 2 is the first structurally characterized tetranuclear hafnium aqua complex. 相似文献
198.
Thermal investigations of two novel coordination compounds, potential precursor of copper sulfides, namely [Cu2(S2O3)2(NH3)4]·5H2O and Na2[Cu4(S2O3)5(NH3)8]·2H2O were performed either in solid state (static air atmosphere), as well as in reaction medium. During both decompositions,
Cu2+ reduction occurs. In solid state decomposition, a mixture containing sulfides and sulfates is observed. In the reaction medium,
CuSy compounds with sulfur content y (0.66<y<1) dependent on thiosulfate concentration are obtained.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
199.
Carp O. Patron L. Mindru I. Marinescu G. Diamandescu L. Banuta A. 《Journal of Thermal Analysis and Calorimetry》2003,74(3):789-799
The thermal behaviour of three coordination compounds, potential precursors of nickel ferrite [Fe2Ni(C4H4O5)2.5(OH)2]NO3·5H2O,[Fe2Ni(C4H8O3N2)4](NO3)8·24H2O and (NH4)[Fe2Ni(C4H4O5)3(OH)3]·3H2O has been investigated to evaluate their suitability as precursors for nickel ferrite. For a complete and reliable assignment of the thermal transformations, the isolable solid intermediates and end products were characterized by IR, X-ray diffraction and Mössbauer investigations. A decomposition scheme is proposed. 相似文献
200.
Biswanath Das D. Nandan Kumar Keetha Laxminarayana B. Ravikanth 《Helvetica chimica acta》2007,90(7):1330-1334
The synthesis of 14‐aryl‐ or 14‐alkyl‐14H‐dibenzo[a,j]xanthenes 3 involving the treatment of naphthalen‐2‐ol ( 1 ) with arenecarboxaldehydes or alkanals 2 in the presence of HClO4?SiO2 as a heterogeneous catalyst was achieved (Table 1), and this reaction was extended to the preparation of N‐[(2‐hydroxynaphthalen‐1‐yl)methyl]amides 5 by a three‐component reaction with urea ( 4a ) or an amide 4b – d as a third reactant (Table 2). 相似文献