基于双(1,2,4-三氮唑基)刚性配体和芳香羧酸的两个配位聚合物的合成、晶体结构及荧光性质

水热条件下,合成了2个结构新颖的金属配位聚合物:[Co_1.5(btb)₂(nbta)(H₂O)₂]_n(1),[Cd(btb)_0.5(nph)(H₂O)]_n(2)(btb=4,4'-二(1,2,4-三氮唑-1-基)联苯,H₃nbta=5-硝基-1,2,3-苯三甲酸,H₂nph=3-硝基邻苯二甲酸)并对它们进行了元素分析,红外光谱及X-射线单晶衍射等表征。结构分析表明,化合物1是一个二维(3,4)-连接3,4L90拓扑结构,并进一步通过O-H…O氢键作用构筑成三维超分子结构。而配合物2是一个三维(3,4,4)-连接的sqc69网络,它的拓扑符号为(4.8²)₂(4².8².10²)(8.10⁴.12)。此外,还研究了这两个配合物的热重和荧光性质。     

3,5-二(吡啶-4-甲氧基)苯甲酸和芳香二羧酸配体构建的具有3,4-连接四重和三重穿插的d10金属配位聚合物

以3,5-二(吡啶-4-甲氧基)苯甲酸(HL)与芳香二羧酸为配体,在水热条件下与Zn(Ⅱ)或Cd(Ⅱ)盐反应得到4个具有3,4-连接多重穿插结构的配位聚合物:[Zn₂L₂(tdc)]n (1),{[Zn₄L₄(Hhdc)₂]·H₂O}n (2),{[Zn₂L₂(Hhdc)]·H₂O}n (3),{[Cd₂L₂(bdtc)(H₂O)]·0.5H₂O}n (4)(H₂tdc=2,5-噻吩二甲酸,H₃hdc=5-羟基间苯二甲酸,H₂bdtc=1,4-苯二硫乙酸).晶体结构分析表明,聚合物1~3具有3,4-连接四重穿插的三维网络结构,拓扑符号分别为(4.8²)(4.8⁵) (1)、(6³)(6⁵.8) (2)和(6³)(6⁵.8) (3).4为3,4-连接三重穿插的二维平面结构,拓扑符号为(6³)(6⁶).测定了配位聚合物1、3和4的热稳定性和荧光性质.     

3,5-二(吡啶-4-甲氧基)苯甲酸和芳香二羧酸配体构建的具有3,4-连接四重和三重穿插的d10金属配位聚合物

以3,5-二(吡啶-4-甲氧基)苯甲酸(HL)与芳香二羧酸为配体,在水热条件下与Zn(Ⅱ)或Cd(Ⅱ)盐反应得到4个具有3,4-连接多重穿插结构的配位聚合物:[Zn₂L₂(tdc)]_n (1),{[Zn₄L₄(Hhdc)₂]·H₂O}_n (2),{[Zn₂L₂(Hhdc)]·H₂O}_n (3),{[Cd₂L₂(bdtc)(H₂O)]·0.5H₂O}_n (4)(H₂tdc=2,5-噻吩二甲酸,H₃hdc=5-羟基间苯二甲酸,H₂bdtc=1,4-苯二硫乙酸).晶体结构分析表明,聚合物1~3具有3,4-连接四重穿插的三维网络结构,拓扑符号分别为(4.8²)(4.8⁵) (1)、(6³)(6⁵.8) (2)和(6³)(6⁵.8) (3).4为3,4-连接三重穿插的二维平面结构,拓扑符号为(63)(66).测定了配位聚合物1、3和4的热稳定性和荧光性质.     

由芳香羧酸和1,3,5-三咪唑基苯为配体构筑的锌、镉配合物的合成、结构和荧光性质

通过水热法得到了2个配位聚合物{[Zn(timb)(BTEC)_0.5]·H₂O}_n(1)和{[Cd(timb)(DPA)]·H₂O}_n(2)(timb=1,3,5-三咪唑基苯,H₄BTEC=均苯四甲酸,H₂DPA=2,2-联苯二甲酸),对它们进行了元素分析、红外光谱分析,并利用X射线衍射测定了它们的单晶结构。 配合物1属于三斜晶系,P1空间群。配合物2属于单斜晶系,C2/c空间群。配合物1拥有一个不寻常的三维框架结构,其拓扑为(4.6³·8⁶)₂(4²·8⁴)(6³)₂;而配合物2具有一维单层纳米管结构。结果说明了金属离子和有机羧酸配体在配合物组装过程中起着非常重要的作用。此外,在室温下对2个配合物进行了荧光性质分析。     

基于两种柔性同分异构羧酸配体的钴(Ⅱ)配合物的合成、结构表征及磁性能研究

分别以E-3-[4-(羧甲氧基)-苯基]丙烯酸(H₂L¹)和E-3-[4-(羧甲氧基)-苯基]丙烯酸(H₂L²)为主配体,合成了3种钴(Ⅱ)配位聚合物：[Co(L¹)(bpp)]_n(1),{[Co(μ₃-OH)₂(L²)₄(bpy)₂(H₂O)₄]·12H₂O}_n(2)和[Co(L₂)(bpy)]_n(3)(bpp：1,3-二吡啶基丙烷,bpy：4,4-联吡啶)。通过元素分析、红外光谱、X射线粉末和单晶衍射对其进行了结构表征。结果表明钴(Ⅱ)离子在这3种配合物中具有不同的配位环境,导致3种配合物具有不同的晶体结构和磁性特征。     

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-tricarboxylic acid)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.     

由芳香羧酸和1,3,5-三咪唑基苯为配体构筑的锌、镉配合物的合成、结构和荧光性质

通过水热法得到了2个配位聚合物{[Zn(timb)(BTEC)_0.5]·H₂O}_n(1)和{[Cd(timb)(DPA)]·H₂O}_n(2)(timb=1,3,5-三咪唑基苯,H₄BTEC=均苯四甲酸,H₂DPA=2,2-联苯二甲酸),对它们进行了元素分析、红外光谱分析,并利用X射线衍射测定了它们的单晶结构。 配合物1属于三斜晶系,P1空间群。配合物2属于单斜晶系,C2/c空间群。配合物1拥有一个不寻常的三维框架结构,其拓扑为(4.6³·8⁶)₂(4²·8⁴)(6³)₂;而配合物2具有一维单层纳米管结构。结果说明了金属离子和有机羧酸配体在配合物组装过程中起着非常重要的作用。此外,在室温下对2个配合物进行了荧光性质分析。     

由芳香羧酸和4,4'-二(1-咪唑基)苯砜为配体构筑的两个配合物的合成、晶体结构及荧光性质

通过水热法得到了2个配位聚合物{[Cd(L)(oba)]·3.5H₂O}_n(1)和{[Cd(L)₂](p-bdc)}_n(2)(L=4,4’-二(1-咪唑基)苯砜,H₂oba=4,4’-联苯醚二甲酸,p-H₂bdc=对苯二甲酸),对它们进行了元素分析、红外光谱分析,并利用X射线衍射测定了它们的单晶结构。晶体结构分析表明,配合物1具有四连接二重穿插的三维网络结构,其拓扑为{6⁵·8}。配合物2具有四连接的二维结构,其拓扑为{4⁴·6²}。此外,在室温下对2个配合物进行了荧光分析。     

基于5-磺酸基间苯二甲酸钠和双三唑烷烃的Cu(Ⅱ)配合物的合成、结构和性质

利用5-磺酸基间苯二甲酸钠(NaH₂sip)和双三唑烷烃,合成了3个配合物[Cu_0.5(btm)(H₂O)](H₂sip)·H₂O}_n (1,btm=双三唑甲烷),{[Cu(btp)₂(H₂sip)(H₂O)](NO₃)·4H₂O}_n (2,btp=双三唑丙烷) 和{[Cu(btb)₂(Hsip)]_n (3,btb=双三唑丁烷)。化合物1为一维双链结构;化合物2为二维四方网络结构,多个二维层依次叠加形成三维超分子结构;化合物3也具有二维层状结构,其中金属铜离子和双三唑丁烷构成的一维双链结构经双齿μ₂-Hsip^2-配体连接构成了二维层状结构。同时对配合物的热稳定性和顺磁共振特性进行了讨论。     

由羧酸配体和铁(Ⅱ)构筑的两个过渡金属配位聚合物的结构、表征和性质

采用水热法合成了2个铁的过渡金属配位聚合物[Fe(Medpq)(BDC)H₂O]_n(1)和{[Fe(Medpq)(QUI)H₂O]·2H₂O}_n(2)(Medpq=2-methyldipyrido[3,2-f:2',3'-h]quinoxaline; H₂BDC=terephthalic acid; H₂QUI=2,3-pyridinedicarboxylic acid),并对其进行了元素分析、红外光谱和热重表征,并用X射线单晶衍射测定结构。2个配位聚合物中的中心铁(Ⅱ)离子,都呈现一个稍微扭曲的八面体几何构型。     

多环芳二酐型聚酯亚胺膜的透气性能

多环芳二酐型聚酯亚胺膜的透气性能李悦生，丁孟贤，徐纪平（浙江大学高分子科学与工程研究所，杭州，３１００２７）（中国科学院长春应用化学研究所）关键词聚醚酰亚胺，聚酯酰亚胺，膜，透气性通常的聚酰亚胺加工性能较差，在芳环二酐的苯环间引入醚键等柔性基团后，其...     

微量元素与疾病诊断治疗的研究现状及展望

对国内外微量元素与疾病的关系及其诊断治疗的研究现状及研究动向进行了综述，包括：微量元素与地方病、癌肿、心血管病、糖尿病、眼病、神经系统病等。参考文献72篇。     

Determination and study on residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil

A QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for the determination of benazolin-ethyl and quizalofop-p-ethyl in rape and soil by high-performance liquid chromatography-tandem mass spectrometry has been developed in this study. The residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil were determined with the developed method. The half-lives of benazolin-ethyl in rape straw and soil were 3.7–5.1 days and 14.3–26.3 days, respectively. The half-lives of quizalofop-p-ethyl in rape straw and soil were 5.0-6.1 days and 0.3–9.7 days, respectively. The residue of benazolin-ethyl and quizalofop-p-ethyl in rapeseed and soil were below the detection limit (i.e., 0.5?mg?kg^?1, the maximum residue level of European Union for quizalofop-p-ethyl).     

Ti-V基储氢合金及其氢化物的物相结构与组分优化设计

Ti-V基储氢合金在室温、常压下即可表现出良好的储氢特性,且质量储氢容量明显高于传统AB₅型储氢合金,从而在氢气的精制和回收、运输和储存及热泵等方面有较早的应用。 此外,在混合气体分离、核反应堆中处理氢的同位素、镍氢电池及燃料电池负极材料等方面也得到了广泛的研究与关注。 基于目前Ti-V基储氢合金的研究现状,概述了该类合金的优势、限制性因素(包括成因)及改性手段。 此外,为了进一步理解Ti-V基合金储氢机理、构建合金组分与储氢特性之间的对应关系,本工作重点围绕Ti-V基储氢合金及其氢化物的结构、组分优化设计展开综述,并对其未来研究方向做出展望。     

钒与糖代谢及糖尿病

微量元素钒作为生物体内必需元素，经证实有很重要的生理学功能，与机体糖代谢有十分密切的关系，且能降低糖尿病动物模型的高血糖，极有可能被开发为治疗糖尿病的药物。     

Synthesis and Optical and Redox Properties of Symmetric and Asymmetric BODIPYs

Herein, we present the synthetic route and the photophysical, electrochemical as well as laser properties of novel red‐emitting boron‐dipyrromethenes (BODIPYs) bearing arylethyne moieties. Such functionality is added along the main axis of the chromophore leading to single‐ and double‐substituted derivatives. The relationship between the dye structure and the lasing properties is studied in detail with the help of the photophysical and electrochemical properties as well as quantum mechanical simulations. The asymmetric substitution of the parent dye induces inhomogeneities in the charge distribution, which leads to an overall loss of the fluorescence capacity, mainly in polar media. Such non‐radiative deactivation processes can be softened by decreasing the electron‐donor ability of the substituent or even avoided by symmetrical substitution. Thus, grafting of the arylethyne moieties at the longitudinal axis of the indacene core results in an effective strategy to develop red‐edge BODIPYs with highly efficient and photostable laser emission.     

Synthesis of Tyrosol and Hydroxytyrosol Glycofuranosides and Their Biochemical and Biological Activities in Cell-Free and Cellular Assays

Tyrosol (T) and hydroxytyrosol (HOT) and their glycosides are promising candidates for applications in functional food products or in complementary therapy. A series of phenylethanoid glycofuranosides (PEGFs) were synthesized to compare some of their biochemical and biological activities with T and HOT. The optimization of glycosylation promoted by environmentally benign basic zinc carbonate was performed to prepare HOT α-L-arabino-, β-D-apio-, and β-D-ribofuranosides. T and HOT β-D-fructofuranosides, prepared by enzymatic transfructosylation of T and HOT, were also included in the comparative study. The antioxidant capacity and DNA-protective potential of T, HOT, and PEGFs on plasmid DNA were determined using cell-free assays. The DNA-damaging potential of the studied compounds for human hepatoma HepG2 cells and their DNA-protective potential on HepG2 cells against hydrogen peroxide were evaluated using the comet assay. Experiments revealed a spectrum of different activities of the studied compounds. HOT and HOT β-D-fructofuranoside appear to be the best-performing scavengers and protectants of plasmid DNA and HepG2 cells. T and T β-D-fructofuranoside display almost zero or low scavenging/antioxidant activity and protective effects on plasmid DNA or HepG2 cells. The results imply that especially HOT β-D-fructofuranoside and β-D-apiofuranoside could be considered as prospective molecules for the subsequent design of supplements with potential in food and health protection.     

Conformations and steric and stacking interactions of trisubstituted ureas and thioureas with alkyl and phenyl groups

The monomeric ν(N—H) vibrations of various trisubstituted ureas of the R₂UPh type and -thioureas of the R₂TUPh type have been studied. The trans—out isomerism in the former and the trans—out—cis isomerism in the latter are discussed from the point of view of steric effect. The monomeric ν(N—H) vibrations of RPhUPh and RPhTUPh are also examined. The single band appearing in the spectrum of both ureas is characteristic of the cis form; this suggests the existence of phenyl—phenyl interaction (the stacking interaction proposed by Galabov et al. [10]). Behavior of ν(N—H) vibrations at several concentrations is shown to be clearly different in the three forms (trans, out and cis). The presence of the cis form is confirmed by solvent effect experiments.     

Ferrocene and ferrocenium modified clays and their styrene and EVA composites

In this work, ferrocene- and ferrocenium-containing salts were employed to modify montmorillonite. X-ray measurements show an increase in the interlayer spacing upon clay modification, which means that the larger and more organophilic cations were inserted into the gallery space of montmorillonite. Attempts to prepare nanocomposites of polystyrene and ethylene vinyl acetate copolymers lead to immiscible systems; the morphology of these systems was elucidated with TEM, XRD and cone calorimetry. The thermal stability of the composites is greater than that of the virgin polymer.