以T型三羧酸配体构筑的具有2D→3D穿插结构的金属有机框架的合成、结构及性质

采用溶剂热合成法,利用T型三羧酸配体3,4',5-联苯三羧酸(H₃BPT=biphenyl-3,4',5-tricarboxylicacid)制备并表征了2个2D→3D穿插结构的金属有机框架结构,{[Ni₃(BPT)₂(bpe)₂(H₂O)₆]·2DMF·7H₂O}_n(1)和{[Ni₃(BPT)₂(bpea)₂(H₂O)₆]·2DMF·5H₂O}_n(2)(bpe=1,2-bis(4-pyridyl)ethylene,bpea=1,2-bis(4-pyridyl)ethane,DMF=N,N-dimethylformamide)。在这2个化合物中,BPT配体和含氮配体bpe或bpea共同连接相邻的Ni(Ⅱ)中心,形成(3,4)-连接的(63)(65.8)二维双层结构。相邻双层结构间相互穿插,形成具有聚轮烷结构的2D→3D互锁结构。气体吸附性质表明,化合物1对CO₂和N₂具有一定的吸附能力。     

一系列由柔性N,N''-双(3-吡啶甲基)胺构筑的螺旋配合物的合成、结构和性质

合成和表征了5个螺旋配位聚合物{[Cu(Hbpma)(H₂O)₄]₂(SO₄)₃·3.5H₂O}_n (1)、{[Ni(Hbpma)(H₂O)₄]₄(SO₄)₆·10.75H₂O}_n (2)、{[Mn(Hbpma)(H₂O)4](SO₄)_1.5·3H₂O}_n (3)、{[Zn(Hbpma)(H₂O)₄]₄(SO₄)₆·4H₂O·4CH₃OH}_n (4)和{[Cu(Hbpma)2(H₂O)₂](SO₄)2·9H₂O}_n (5),其中bpma代表N,N'-双(3-吡啶甲基)胺。晶体结构分析表明配合物1~4为一维链状结构,配合物5为二维层状结构,其中金属离子由质子化的bpma配体桥连。值得注意的是,采取反-反式构象的柔性bpma配体使得配合物1和2为假螺旋链结构,配合物3和4为螺旋链结构,配合物5为螺旋层结构。同时研究了配合物的磁性和热稳定性。     

One‐Pot Synthesis of Aliphatic Nitro Compounds by Michael/retro‐Claisen Fragmentation Domino Reaction

A novel and concise method for the construction of γ‐nitro ketones and 1,3‐dinitro compounds with chemoselective acyl transfer has been presented under basic conditions via one‐pot reactions. These reactions feature high atom‐ and step‐economic possess, mild condition and simple operation for one‐pot synthesis of aliphatic nitro compounds. This protocol provides the products in good yields. The possible reaction mechanism has also been proposed.     

Efficient Synthesis of Triarylamines Catalyzed by Copper(I) Diazabutadiene Complexes

Cuprous chloride was coordinated by diazabutadiene (DAB‐R) ligands to form Cu(I)‐(DAB‐R) complexes, most of which have a 1:1 ratio of Cu to DAB‐R as reported. In the case of a special DAB‐ⁱPP, N,N′‐bis(2,6‐diisopropylphenyl)‐1,4‐diaza‐1,3‐butadiene, an unexpected composition of complex was found with the formula Cu(I)Cl(DAB)₂. When employed as catalyst for triarylamine synthesis from the coupling of aryl halides with primary and secondary arylamines, the new Cu(I)‐(DAB‐ⁱPP) complex displayed high efficiency.     

两个三维柔性功能化双苯并咪唑金属N-杂环卡宾的合成和结构

由1,1'-双苄基-3,3'-氧双(亚乙基-2,1)-二苯并咪唑六氟磷酸盐(L1)和1,1'-双(吡啶-2-甲基)-3,3'-氧双(亚乙基-2,1)-二苯并咪唑六氟磷酸盐(L2)为配体合成了[Hg(C₃₂H₂₈N₄O)](CH₃COO)(PF₆)₂(1)和[NiCl(C₃₀H₂₈N₆O)](PF₆)₂(2),并对其进行了结构表征。配合物1是一个罕见的三价态Hg配合物,为单斜晶系P2₁/c空间群,配合物2为单斜晶系P2₁/n的配合物。1和2中存在O-H…F,C-H…F,C-H…Cl,C-H…π,P-F…π氢键作用和π-π堆积作用,并以此分别形成了3D超分子结构。     

Transition Metal Free Chemoselective Reduction of α,β‐Unsaturated Ketones to Saturated Ketones Using Tosyl Hydrazide as a Hydrogen Donor

An efficient, inexpensive and simple method for the reduction of various α,β‐unsaturated ketones to corresponding saturated ketones using tosyl hydrazide as a hydrogen donor in DMF using calcium oxide powder has been reported. A variety of enones underwent reduction without forming undesirable side products. High chemoselectivity, broad functional group tolerance and good yields are the noteworthy features of this protocol.     

Adsorption of arsenate on lanthanum-impregnated activated alumina: In situ ATR-FTIR and two-dimensional correlation analysis study

Lanthanum modified materials have been widely used for the removal of hazardous anions.In this study,in situ ATR-FTIR and two-dimensional correlation analysis were employed to investigate the adsorption mechanism of arsenate（As（V）） on lanthanum-impregnated activated alumina（LAA）.Our results showed that electrostatic interaction attracted As（V） anions to the LAA surface,and then As（V） could form monodentate configuration on the LAA surface at pH 5-9.The result of 2D-COS showed that two coexistent adsorbed As（V） species,H₂AsO₄^- and HAsO₄^2-,were adsorbed on the LAA surface without specific sequence at different pH conditions,indicating a negligible role of the incorporated protons of As（V） on the adsorption affinity to LAA surface.The results of this study reveal insights into LAA surface complexes on the molecular scale and provide theoretical support to new metal oxides design for efficient arsenic removal.     

Quantum-chemical study on the catalytic activity of TinRumO2(1 1 0) surfaces on chlorine evolution

Based on the generalized gradient approximation (GGA), Perdew-Wang-91 (PW91) combined with a periodic slab model has been applied to study the catalytic activity of chlorine evolution on TinRumO2(1 1 0) surface. Metal oxide model TinRumO2 has been established with pure TiO2 and RuO2 on the basis set of Double Numerical plus polarization (DNP), in which the proportion of n:m was 3:1, 1:1, or 1:3. Analysis on the reaction activity in the electrochemical reaction and the electrochemical desorption reaction was based on Frontiermolecular orbital theory. The results show that the TinRumO2 with a ratio of Ti:Ru at 3:1 is best facilitates the electrochemical reaction and electrochemical desorption reaction to produce M-Clads intermediate and precipitate Cl2. In addition, the adsorption energy of Cl on the surface of Ti3Ru1O2 possesses the minimum value of 2.514 eV, and thus electrochemical desorption reaction could occur most easily.     

Supported carbon dots decorated with metallothionein for selective cadmium adsorption and removal

Carbon dots are prepared and immobilized onto spherical SiO_2 through a one-step thermal oxidation and then decorated with metallothionein(MT), a protein with high affinity towards thiophilic metals. The MT-carbon dots composites are characterized by means of FT-IR, SEM and TGA, giving rise to a MT loading amount of 823 μg g~(-1). The adsorption of cadmium by the composites is a fast process and follows Langmuir model. In comparison with native SiO_2, a 2- and 2.4-folds improvement on the static and dynamic adsorption capacity of the composites for cadmium are obtained, respectively. Moreover,the adsorption efficiency is not affected by the presence of other metals. Finally, the composites are successfully applied for the removal of cadmium in a series of environmental water samples.     

纤维素基吸附分离材料研究进展

以纤维素为原料制备吸附分离材料可以减少对石油资源的依赖,并具有成本低、环境友好和生物相容性好等优点。利用纤维素中的羟基基团,通过交联、接枝、引入无机粒子或与聚合物复合,可以制备出微球和薄膜等不同形态的吸附分离材料,广泛应用于生物医学,废水处理、气体分离等领域。本文结合近五年来国内外纤维素及其复合材料在吸附分离领域的研究近况,从水、油、重金属、气体和有机物的应用进行了综述,总结了纤维素基吸附分离材料的研究尚存在的问题,探讨了今后的研究方向。