Synthesis and characterization of bis-[1]rotaxanes via salen-bridged bis-pillar[5]arenes

The series of salen-bridged bis-pillar[1]arenes were conveniently prepared by condensation reaction of5,5'-methylenebis(2-hydroxybenzalde hyde)or 5,5'-(propane-2,2-diyl)bis(2-hydroxybenzaldehyde)with mono-amido-functionalized pillar[5]arenes containing different terminal aminoalkyl groups in refluxing ethanol.The^1H NMR and 2D-NOESY spectra indicated that the salen-bridged bis-pillar[5]arenes with longer allcylene linker(n=3,4,6)formed the fascinating bis-[1]rotaxanes,while the salenbridged bis-pillar[5]arenes with short hydrazine and ethylenediamino linker(n=0,2)predominately existed in free form.The single crystal structure of the bis-pillar[5]are ne ambiguously indicated that two propylenediamino linker inserted in to two cavities of pillar[5]arene to form a novel bis-[1]rotaxanes.     

Highly active bifunctional salenTi(Ⅳ) catalysts for asymmetric cyanosilylation of aldehydes and TMSCN

A novel enantiopure salen ligand bearing a diphenylphosphine oxide on the 3-position of one aromatic ring was synthesized and combined with Ti(Oi-Pr)_4 as a monometallic bifunctional catalyst for asymmetric cyanosilylation reaction of aldehydes with tnmethylsilyl cyanide(TMSCN).The catalyst system exhibited excellent activity and moderate enantioselectivity.The addition of TMSCN to 4-nitrobenzaldehyde in the presence of 1 mol%catalyst loading could complete within 10 min at ambient temperature. An intram...     

双芳烃桥连salen配体的合成及其钛配合物在硅腈对醛的不对称加成反应中的应用

新型双芳烃桥连的salen钛配合物是一种高活性的催化三甲基硅腈对醛不对称加成反应的催化剂,底物与催化剂用量比率可达1 000:1.由(R,R)-1,2.环已二胺和3,5-二叔丁基水杨醛合成的催化剂4在催化三甲基硅腈对醛不对称加成反应中达到87%的对映选择性.     

A new organic–inorganic hybrid based on Mn–salen and decavanadate

An organic–inorganic hybrid based on Mn-salen and decavanadate, [NH₄]₂[Mn(salen)(H₂O)₂]₄[V₁₀O₂₈]?·?6H₂O (1) (salen?=?N,N′-ethylene-bis(salicylideneiminate)), has been synthesized by the strategy of secondary building units in mixed methanol–water solution and was structurally characterized by single-crystal X-ray diffraction, elemental analyses, IR, and UV-Vis. The [Mn(salen)(H₂O)₂]⁺ cations and water molecules are located in the interspaces among the polyoxoanions [V₁₀O₂₈]^6? forming a POM-based supramolecule. Compound 1 is the first example of metal-Schiff-base polyoxovanadates. The photocatalytic analysis, cyclic voltammetry, and electrocatalytic analysis of 1 have been investigated.     

水溶性Pt(Ⅱ)-Salen配合物的合成、表征和光催化制氢研究

本文合成了一种水溶性的Pt(II)-Salen配合物(Salen=双5-磺酸钾水杨醛合邻苯二胺席夫碱),将其用于光催化制氢.研究发现在光催化制氢体系中仅存在Pt(II)-Salen配合物和三乙胺(TEA)而没有额外加入催化剂时,在可见光照射下有氢气产生.进一步的研究表明,Pt(II)-Salen配合物在体系中既是光敏剂,又是催化剂Pt纳米粒子的前体.同时,制氢体系中除了TEA外没有使用有机溶剂.该结果为简化多组分制氢体系提供了新思路.     

Cu(II)-imprinted styrene-divinylbenzene beads as a new sorbent for flow injection-flame atomic absorption determination of copper

The paper reports preparation and analytical features of a new Cu(II)-imprinted polymer, based on salen-OMe ligand 2,2′-[ethane-1,2-diylbis(nitrilo(E)methylylidene)]bis(6-allyl-4-methoxyphenol) and styrene-divinylbenzene matrix, as well as its application to on-line preconcentration and flame atomic absorption determination of copper. Sorbent beads (average diameter of 60-80 µm) were obtained using suspension polymerization technique and employed as a column filling. Copper sorption was the most effective at pH 6.8, whereas the highest elution effectiveness was observed when 0.5% HNO₃ was applied. The sorbent exhibited good long-term stability and acid resistance. Enrichment factor (EF) of 12 was found for 60 s loading time and loading flow rate of 4 mL min^− 1. EF value may be further increased by expanding the loading time and/or flow rate. Batch sorbent capacity in optimal pH conditions was found to be 0.16 mmol g^− 1 (9.55 mg g^− 1) of a dry polymer. Calcium(II) turned out to be the only significant interferent. Cadmium(II), silver(I), nickel(II), zinc(II) in concentrations lower than about 1 mg L^− 1 did not disturb copper(II) preconcentration. Different calibration methods such as: set of standards method (SSM), standard addition method (SAM) and combinatory calibration method (CCM) were employed for copper(II) determination in tap water, spring mineral water and certified reference material. Analysis of EU-H-3 reference material confirmed good accuracy of the proposed method. Relative standard deviation (RSD) was 3.2 for standard addition method and 2.8% for set of standard calibration method. Detection limit for sample consumption 16 mL was 1.03 and 1.07 µgL^-1 respectively.     

新型晶态层状载体聚(苯乙烯-苯乙烯基膦酸)-磷酸锌轴向固载手性Salen Mn(Ⅲ)的合成及催化烯烃的环氧化性能

在温和条件合成了新型晶态层状有机聚合物-无机杂化载体材料聚(苯乙烯-苯乙烯基膦酸)-磷酸锌, 结合实验数据提出了其可能的理想结构模型. 对该载体进行氯甲基化和酚羟基化修饰后, 轴向配位固载手性Salen Mn(Ⅲ), 合成了一类新型的多相催化剂. 以间氯过氧苯甲酸为氧源, 考察了其对α-甲基苯乙烯及茚不对称环氧化反应的催化性能. 结果表明, 这类固载催化剂具有与均相Jacobsen催化剂相当或更高的催化活性和对映选择性, 并具有优良的重复使用性. 特别是在该氧化体系中, 当无助催化剂N-甲基吗啉氮氧化物(NMO)参与时, 固载催化剂获得更高的转化率及e.e.值, 这为其扩大化生产增加了可能性.     

The enantioselective high-pressure Diels-Alder reaction of 1-methoxybuta-1,3-diene with tert-butyldimethylsilyloxyacetaldehyde catalyzed by (salen)Co(II) and (salen)Cr(III)Cl complexes

The high-pressure (10-11 kbar) reaction of 1-methoxybuta-1,3-diene (1) with tert-butyldimethylsilyloxyacetaldehyde (2), catalyzed by the chiral (salen)Co(II) 4 or (salen)Cr(III)Cl 5 complexes, has been studied. We found that the reaction afforded, in good yield (up to 90%) and both with very good diastereoselectivity (up to 92%) and enantioselectivity (up to 94% ee), the [4 + 2]cycloadducts 3, which are compounds of significant synthetic interest.     

Synthesis and Characterization of Chiral Organogallium and Indium Complexes with Salen Ligands

Several new chiral organogallium and indium complexes with chiral Salen(1 and 2) as anxciliary ligands have been synthesized and characterized by elemental analysis,IR,^1H NMR and Mass spectroscopy.For the gallium,Mono and bimetallic complexes were obtained,whereas ring closure complexes of indium were obtained.     

Novel Water-Soluble 4,4-Disubstituted Ruthenium(III)-Salen Complexes in DNA Stranded Scission

Salen-type Ru(III) complexes are found to be capable of reacting with physiologically acceptable oxidants. The water solubility and DNA affinity of these Ru(III)-salen complexes are enhanced by the utilization of a variety of charged groups through the formation of peptide bonds. In the presence of hydrogen peroxide, modified Ru(III)-salen complexes are capable of nicking DNA. In addition, the reactivity in DNA cleavage increases along with the total number of positive charges retaining in Ru(III)-salen complexes and less influence in the electronic effect. Using ³²P-end-labeled oligonucleotides and high resolution polyacrylamide gel electrophoresis, Ru(III)-salen complexes are found to randomly cleave DNA regardless of the DNA secondary conformation such as bulge, inter-loop, or double-stranded regions. The possible reactive species of Ru(III)-salen complexes in DNA cleavage is considered as the hydroxyl radical and high valent oxoruthenium(IV) species according to the UV titration, quenching studies, and reaction with varied oxidants.