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71.
1 INTRODUCTION Recently, the low-spin square-planar nickel(II) complexes and high-spin octahedral nickel(II) complexes with Schiff base ligands have received much attention in optical materials[1~3]. Some nic- kel(II) complexes are widely used as lubricating oil, rubber industry additives, a fire-resistant additive and fungicide for leather[4~7]. Also, their adducts with nitrogen have attracted broad attention due to their potential applications as organic conductors and magnetic mate… 相似文献
72.
《Tetrahedron letters》2003,44(26):4831-4834
A convenient and efficient synthesis of 3,5-di(silylethynyl)phenylacetylene and p-[3,5-di(silylethynyl)phenylethynyl]phenylacetylene has been carried out. These compounds serve to prepare nanometer-sized conjugated 1,4- and 1,3,5-phenylethynyl oligomers, by means of cross-coupling with a convenient haloaryl derivative, catalysed by palladium(II), in excellent yields. The phenylethynyl homologues show fluorescence emission, the wavelength of which is displaced by approximately 20 nm by each phenylethynyl unit increasing the conjugate chain. 相似文献
73.
Grzegorz WojciechowskiMa?gorzata Ratajczak-Sitarz Andrzej KatrusiakBogumil Brzezinski 《Journal of Molecular Structure》2002,612(1):59-64
The crystals of 5,5′-dibromo-3-diethylaminomethyl-2,2′-biphenol N-oxide were studied by X-ray and FT-IR spectroscopy. Within this molecule two short OHO intramolecular hydrogen bonds are formed. The NO?H+?O− bond between the OH and the N-oxide groups is very strong, of 2.419(7) Å between the oxygen atoms. The proton potential of this hydrogen bond is flat, broad and has probably no barrier—consequently it could not be located from X-ray diffraction data. The other hydrogen bond formed between two hydroxyl groups appears asymmetrical from FT-IR spectra, and shows also relatively limited proton polarizability. The molecular conformation is non-planar, due to strong overcrowding effect between the oxygen atoms involved in the hydrogen bonds. 相似文献
74.
‘Head-to-head’ oligo-N-methylpyrrole peptide dimers linked by a methano[1,5]diazocin scaffold are presented in racemic as well as chiral fashion. Their DNA binding activities were assayed on calf thymus DNA, poly(dA-dT)2, and poly(dC-dG)2 by NMR and ECD spectroscopies, and fluorescence probe displacement assay. The presented dimers prefer AT sequences, but show higher affinity to poly(dC-dG)2 than distamycin A. The (4R,9R) configuration of methanodiazocin bridge was found to be better suited for interaction with ct-DNA and poly(dA-dT)2 than (4S,9S) configuration. 相似文献
75.
The activity of Mg−Al basic heterogeneous catalysts in the reactions of alcohols with ethylene oxide was studied. The kinetics
of alcohol oxyethylation was examined. The kinetic equation of the reaction was determined and the structure of products was
studied. The distribution coefficients of the oxyethylation reaction products were calculated. A comparison of the catalytic
activity of Mg−Al hydroxides and products of their thermal treatment was made. 相似文献
76.
Tetra-Schiff base macrocyclic compound containing benzo-12-crown-4 was synthesized via condensation of 2,6-diformyl-4-methyl-phenol with 4′,5′-diaminobenzo-12-C-4 promoted by proton. The compound was characterized by MS,IR ^1HNMR spectroscopy and elemental analysis. 相似文献
77.
DENG Shui-Quan HUANG Xiao-Yin ZHUANG Hong-HuiHUANG Jin-LingState Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences Fuzhou Fujian ChinaLIN Zhen-GuangDepartment of Chemistry Fujian Teachers'''' University Fuzhou Fujian China 《中国化学》1994,12(3):270-276
An open chain compound was obtained by reaction of benzil with thiocarbohy-drazide in acidic condition. Its derivative, namely, benzil bis-(5-isopropylidene-3-thiocarbohydrazone) has been structurally characterized by X-ray single crystal diffraction method. Crystallographic data: C22H26N8S2, Mr=466.62, monoclinic, space group C2/c, a=12.215(3), b=11.473(2), c=17.032 (3)A, B=98.96(2)0, V=2357.7(9)A3, Z=4, Dc=1.32 g/cm3, F(000)=1040, u(Mo Ka)=2.43 cm-1. Final R=0.050, Rw=0.061 for 1103 unique and observed reflections with I> 3o(I). The effect of the structures on the formation of the open-chain intermediates during the cyclization of (2:2) Schiff base macrocyclic compound has been discussed and a possible mechanism for the ring closure has been suggested. 相似文献
78.
碱金属沸石上乙醇双分子缩合反应及其机理 总被引:1,自引:0,他引:1
首次发现在碱金属X沸石上乙醇能够发生以正丁醇为主产物的双分子缩合反应,在所研究的催化剂中,含Rb的LiX沸石表现出较高的反应活性和选择性。反应机理的研究表明,反应不经过aldol缩合步骤。在此基础上,对反应机理提出了新建议:在碱性沸石作用下,乙醇的β-位C-H键被活化,双分子脱水导致缩合。碳链的增长按此模式进行。 相似文献
79.
用氨基三氮唑硫代丙酸乙酯与取代苯甲醛反应,合成了6个新型的5-氨基-1H-1,2,4-三氮唑-3-硫代-2′-丙酸乙酯类Schiff碱,其结构经^1H NMR,IR,MS和元素分析表征。 相似文献
80.
A new Co(II) complex with tridentate Schiff base ligand with a N,N,O donor set has been synthesized and characterized by single X-ray technique and spectroscopic techniques. The thermochemical properties have been studied. X-ray structure analysis of the title compound Co(II)L2 [HL = 2-methyl-6-(2′-hydroxybenzylideneamino) pyridine] shows that the polyhedron around Co(II) is a distorted tetrahedron, and the self-assembly via intermolecular π-π interactions leads to a three-dimensional network. Crystal data for the title complex C26H22CoN4O2: Monoclinic, space group Ia, a = 11.741(7) Å, b = 8.149(5) Å, c = 22.764(16) Å, β = 98.530(12)°, V = 2154(2) Å3, Z = 4. 相似文献