双安息香缩三乙四胺双核过渡金属配合物的合成、表征与载氧性质

合成了双安息香缩三乙四胺及其与草酸共同配位的Co(Ⅱ)、Ni(Ⅱ)、Cu(Ⅱ)、Zn(Ⅱ)、Cd(Ⅱ)的三元双核金属配合物.经质谱、红外光谱、元素分析、摩尔电导与磁矩测定及热分析等方法表征.用气体吸收装置探讨了配合物在DMF溶剂中的载氧性质和载氧动力学.     

Synthesis,Characterization, and Catalytic Exploration of Mononuclear Mo(VI) Dioxido Complexes of (Z)-1-R-2-(4′,4′-Dimethyl-2′-oxazolin-2′-yl)-eth-1-en-1-ates

The coordination chemistry of the title ligands with Mo metal centers was investigated. Thus, the synthesis and characterization (NMR, X-ray diffraction) of four mononuclear formally Mo(6+) complexes of (Z)-1-R-2-(4′,4′-dimethyl-2′-oxazolin-2′-yl)-eth-1-en-1-ates (L: R = –Ph, –Ph-p-NO₂, –Ph-p-OMe and –t-Bu), derived from the part enols (LH), is described. The resulting air-stable MoO₂L₂ complexes (1–4) exist, as shown by single-crystal X-ray diffraction experiments, in the cis-dioxido-trans(N)-κ²-N,O-L conformation in the solid state for all four examples. This situation was further probed using semi-empirical PM6(tm) calculations. Complexes 1–4 represent the first Mo complexes of this ligand class and, indeed, of Group 6 metals in general. Structural and spectroscopic comparisons were made between these and related Mo(6+) compounds. Complex 1 (R = –Ph) was studied for its ability to selectively catalyze the production of poly-norbornene from the monomer in the presence of MAO. This, unfortunately, only resulted in the synthesis of insoluble, presumably highly cross-linked, polymeric and/or oligomeric materials. However, complexes 1–4 were demonstrated to be highly effective for catalyzing benzoin to benzil conversion using DMSO as the O-transfer agent. This catalysis work is likewise put into perspective with respect to analogous Mo(6+) complexes.     

反相高效液相色谱法结合计时波长切换紫外检测法测定苯妥英及其中间体的含量

以盐酸酸化的二甲亚砜为溶剂,铁盐催化空气氧化安息香制备苯偶酰,再由苯偶酰与尿素缩合制备苯妥英。在此合成过程中需对反应液中安息香的浓度、中间产物苯偶酰的含量以及最终产物苯妥英的浓度进行检测。试验提出了采用反相高效液相色谱法结合计时波长切换紫外检测法对上述各化合物进行测定。将所需测定的样品溶于乙腈中,所得溶液经0.45μm滤膜过滤。取滤液(进样量为20μL)通过kromasil 100-5C18色谱柱(200mm×4.6mm,5μm),以体积比为80∶20的乙腈-水溶液作为流动相进行等度洗脱,洗脱液按预设程序进行计时紫外检测。在0~3.0min和波长218nm处检测苯妥英;在3.0~4.0 min和波长247nm处检测安息香;在4.0~6.0min和波长260nm处检测苯偶酰。3种化合物标准曲线的线性范围均为0.1~100mg·L^-1,并测得其检出限(3S/N)依次为0.010,0.003 0,0.007 0mg·L^-1。在实际样品基础上加入3个浓度水平的混合标准溶液进行回收试验,测得3种化合物的回收率为95.4%~105%;测定值的相对标准偏差(n=6)为1.8%~4.2%。     

Sulfated Tin Oxide: A Reusable and Highly Efficient Heterogeneous Catalyst for the Synthesis of 2,4,5-Triaryl-1H-imidazole Derivatives

One-pot, three-component condensation of benzil/benzoin, substituted aromatic aldehydes, and ammonium acetate in an ethanol–water (1:1, v/v) solvent system using sulfated tin oxide catalyst under reflux condition afforded corresponding 2,4,5-triaryl-1H-imidazoles in excellent yield. The remarkable advantages offered by this method include green and reusable catalyst, mild reaction conditions, fast reaction rate, and excellent yield of products. This novel methodology maintains atom economy and an environmentally friendly approach.     

Amine‐Linked N‐Heterocyclic Carbenes: The Importance of an Pendant Free‐Amine Auxiliary in Assisting the Catalytic Reaction

We have successfully expanded the library of amino–NHCs with varying substituents on the amine group, leading to insight about the instability of NHCs arising from the intermolecular interaction of the dangling amine side‐arm. However, the pendant amine plays an important role with respect to the catalytic process, resuscitating the catalytic activity of unsaturated NHC’s through a synergistic effect invoked by the secondary amine. This proof of concept allows us to expand the spectrum of catalysis to C C, as well as C B bond formation.     

Preparation, Characterization, and Catalytical Application of MgCoAl-Hydrotalcite-Like Compounds

MgCoAl-hydrotalcite-like compounds(MgCoAl-HTLcs)were synthesized using the copre- cipitation method of variable pH values.The effect of each factor on the preparation of HTLcs was discussed systematically,which included pH values,mole ratios of Mg~(2 )to Co~(2 ),the concentrations of the solution,and the temperature and time of the hydrothermal treatment.Besides.the thermal de- composition of MgCoAl-HTLcs was discussed.X-ray diffraction,thermogravimetric analysis,and FT-IR spectroscopy were performed to characterize the MgCoAl-HTLcs samples.The results showed that when the pH=7.6-8.5 or 5.5-6.2,atomic ratios of(Mg~(2 ) Co~(2 ))/Al~(3 )=2 and Mg~(2 )/Co~(2 )ranging from 1.00 to 2.00,temperature and time of hydrothermal treatment being 110℃and 6 h,unique MgCoAl-HTLcs with high crystallinity could be obtained.When the calcination temperature was up to 250℃,the MgO phase was detected coexisting with Al_2O_3 and MgAl_2O_4 was highly spreaded on the derived mixed oxides. The synthesis reaction of benzoin methyl ether with methanol and benzaldehyde was chosen to study the catalytic activity of MgCoAl-HTLcs.The catalyst showed high activity and high stability in the synthesis of benzoin methyl ether in the feasible condition.     

苯偶姻醚类对碘鎓盐引发环氧聚硅氧烷光聚合的促进作用

鎓盐引发的阳离子光聚合已有很多报道,但多偏重于低分子量环氧化合物的溶液聚合,对环氧树脂薄膜本体聚合的报道较少。鎓盐在紫外区(>300nm)吸收光的能力很低,苯偶姻醚可促进氟硼酸二苯碘[Ph_2I BF_4~-]在300—400nm的光分解,从而有助于它引     

SBA-15/NiCl2催化超声合成喹喔啉衍生物

以苯偶姻和邻苯二胺为原料,SBA/NiCl2为催化剂,在超声条件下合成了喹喔啉衍生物,其结构经1H NMR和IR确证。考察催化剂类型、原料摩尔比和催化剂的用量对产率的影响。在最佳条件(苯偶姻和邻苯二胺物质的量比为1.0/1.0,催化剂用量为苯偶姻的10 mmol%,于70℃超声反应5 min)下,产率可达94.7%。     

Direct Electrochemical Synthesis and Crystal Structure of a New Mononuclear Copper(Ⅱ) Complex: [(bipy)_2Cu(PhCOO)]ClO_4·(benzil) (benzil = 1,2-Diphenyl-ethane-1,2-dione)

A new mononuclear copper(Ⅱ) complex [(bipy)2Cu(PhCOO)]ClO4·(benzil) (bipy = 2,2′-bipyridine, benzil = 1,2-diphenyl-ethane-1,2-dione) was synthesized by direct electrochemical oxidation of Cu electrode in an acetonitrile solution with benzoic acid, 2,2′-bipyridine and benzoin. As soon as the current flowed in the cell, benzoin was oxidized to benzil quickly. The crystal structure was determined by X-ray diffraction. It belongs to monoclinic system, space group P21/c with a = 14.860(2), b = 20.784(3), c = 11.9150(17) , β = 101.401(3)°, V = 3607.3(9) 3, Z = 4, Mr = 806.69, Dc = 1.485 g/cm3, F(000) = 1660, μ = 0.742 mm-1, R = 0.0788 and wR = 0.1519 for 6254 observed reflections (I > 2σ(I)). The complex contains a mononuclear [(bipy)2Cu(PhCOO)]+ cation, a solvate benzil molecule and a ClO4- anion which locates around the cation outside acting as the counter ion. The Cu(Ⅱ) ion is coordinated by two 2,2′-bipyridines and one benzoato ligand to form a distorted square-pyramid.