诺氟沙星-铜(Ⅱ)-多吡啶配合物的超氧化物岐化酶活性及电化学研究

应用氮蓝四唑(NBT)-光照法研究了系列诺氟沙星(NFA)-铜(Ⅱ)-多吡啶配合物:[Cu(NFA)(tatp)(H2O)](ClO4)2(1),[Cu(NFA)(bipy)(H2O)](ClO4)2·2.5H2O(2)和[Cu(NFA)(dppz)(H2O)](ClO4)2·H2O(3)[NFA=诺氟沙星,tatp=1,4,8,9-四氮三联苯,bipy=1,1'-联二吡啶,dppz=二吡啶并[3,2-α;2',3'-c]吩嗪]在水溶液中的超氧化物岐化酶(SOD)活性,并用循环伏安法研究了配合物的电化学性质.结果表明,三种配合物均具有良好的SOD活性,表观催化速率常数分别为6.34×107、3.74×107和7.17×107 mol-1·L·S-1.     

由2,6-吡啶二羧酸根构筑的两种铈(Ⅳ)配合物的合成、结构及热性质

采用水热法合成了2种铈(Ⅳ)配合物[Ce(dipic)3]·(H2bipy)·4H2O(1)和[Ce(dipic)3]·(H2bpa)·3.5H2O(2)(2,6-H2dipic=2,6-吡啶二羧酸,bipy=4,4′-联吡啶,bpa=二(4-吡啶基)胺),并通过X射线单晶衍射、元素分析、FTIR及热重分析对其结构和组成进行了表征。单晶衍射结构表明:配合物1和2的晶体都属于三斜晶系,P1空间群。配合物的中心金属铈(Ⅳ)离子被3个完全去质子化的2,6-吡啶二羧酸根环绕,配体2,6-吡啶二羧酸的羧基均以单齿形式配位。热分析表明2个配合物在64和50℃开始发生分解。     

配合物[RE_2(H_2L)_2(HL)_2(2,6-H_2PDA)(H_2O)_2]·2H_2O的合成、晶体结构及其与DNA作用方式初探

以N-(2-异丙酸)-邻羟基苯甲酰腙(C10H10N2O4,H3L)、2,6-吡啶二甲酸(2,6-H2PDA)与RE(NO3)3·nH2O(RE=Pr,Eu)在室温下反应,合成了配合物1[Pr2(H2L)2(HL)2(2,6-H2PDA)(H2O)2]·2H2O和配合物2[Eu2(H2L)2(HL)2(2,6-H2PDA)-(H2O)2]·2H2O,对其进行了元素分析、红外光谱、紫外光谱等表征,测定了两种配合物的晶体结构.通过紫外吸收光谱、荧光发射光谱和稳态荧光猝灭方法及其与溴化乙锭(EB)的竞争实验研究了两种配合物与小牛胸腺DNA的作用情况.结果表明,两种配合物与小牛胸腺DNA均是以插入方式结合的.     

基于3-氧醚乙酸-邻苯二酸和N-辅助配体的锌和镉配合物的合成、晶体结构及荧光性质

水热法合成得到2个配合物,{[Zn7(L)4(bpe)2(μ3-OH)2(H2O)8]·4H2O}n(1),和{[Cd3(L)2(bpy)2.5(H2O)]·5.5H2O}n(2)(H3L=3-(carboxymethoxy)benzene-1,2-dioic acid,bpe=1,2-bis(4-pyridyl)-ethene,bpy=4,4′-bipyridine),并采用元素分析、红外光谱、热重和X-射线单晶衍射对其结构进行表征。配合物1中,配体L3-和bpe连接[Zn5(μ3-OH)2]中心形成一维链,这样的链通过氢键连接成三维的超分子结构。配合物2呈现(3,3,6)连接的网状结构。此外,对配合物1和2的荧光性质进行了研究。     

吡啶-2, 6-二[N-(1′-咪唑基丙基)甲酰胺]及其锌(Ⅱ)、镉(Ⅱ)配合物的合成与光谱学研究

以吡啶-2,6-二甲酸为起始原料,经酯化后与N-(3-氨基丙基)咪唑反应合成了有机配体分子吡啶-2,6-二[N-(1'-咪唑基丙基)甲酰胺](L)及其锌(Ⅱ)、镉(Ⅱ)配合物。配体L的结构经1H NMR、13C NMR、IR、UV和元素分析表征,并采用单晶X-射线衍射方法确定了L的晶体结构,L属于正交晶系,Pbcn空间群,晶胞参数a=25.03(2),b=8.933(7),c=20.101(16),α=β=γ=90°,V=4495(6)3,Z=8,Dc=1.287g·cm-3,μ=0.095mm-1,F(000)=1856。通过元素分析确定锌(Ⅱ)、镉(Ⅱ)配合物的组成分别为(C19H23N7O2)2Zn2(ClO4)2·(CH3O)2·2H2O和(C19H23N7O2)2Cd2(ClO4)·(CH3O)3·2H2O,并采用对比分析的方法讨论了配位前后游离配体L和两种配合物的红外吸收光谱和紫外吸收光谱的谱学性质。     

通过铜(Ⅱ)、铁(Ⅲ)和铁(Ⅱ)与2,2'-联咪唑协同作用构筑的超分子及其结构的研究

在水和乙醇溶剂中,通过Cu(Ⅱ),Fe(Ⅲ)和Fe(Ⅱ)与2,2'-联咪唑协同作用,构筑了四种新的超分子配合物[Cu(H2biim)(gly)(H2O)]Cl·H2O(1),[Cu(H2biim)(C3H2O4)(H2O)]·1.5H2O(2),[Fe2(μ-O)(H2biim)4(H2O)2](NO3)4·C2H5OH(3)和[Fe(H2biim)3]SO4(4)(H2biim=2,2'-联咪唑;gly-=甘氨酸根;C3H2O24-=丙二酸根).并通过元素分析,红外光谱和X射线单晶衍射对其组成、结构和谱学性质进行研究.H2biim配体,丙二酸根和甘氨酸根三种配体都采用了双齿螯合方式与金属离子配位.配合物1～4中,通过H2biim配体的N-H键与阴离子、水分子和溶剂分子形成多种氢键,如R12(7),R22(9)和R12(4)等,以及H2biim配体之间的π-π堆积,阳离子不对称单元构筑了多维结构的超分子配合物.     

三嗪吡唑类配位超分子化合物的合成、结构及光催化活性

在水和乙醇的混合体系中合成了2个配位化合物[Co(Bpz*ea T)(H2O)3]·2H2BTC·2H2O(1)和[Cu(Bpz*ea T)(H2O)3]·2H2BTC·CH3CH2OH·H2O(2)[Bpz*ea T=2,4-二(3,5-二甲基吡唑)-6-二乙胺基-1,3,5-三嗪;H3BTC=均苯三甲酸].通过元素分析、红外光谱、紫外光谱、热重分析、X射线粉末衍射以及X射线单晶衍射方法对配合物进行了表征.结构分析表明,配合物1和2的中心金属均为六配位,形成扭曲的八面体构型.通过分子间氢键的作用,配合物1和2分别被连接成三维和二维的超分子结构.此外,对2个配合物的光催化活性进行了研究.     

单核Ru(Ⅲ)-edta类配合物的合成﹑结构及性质研究

采用K[Ru(Hedta)Cl]·1.5H2O(edta为乙二胺四乙酸根)与含氮杂环配体5-(4-吡啶)四唑(4-ptz)或2,5-吡啶二甲酸(2,5-Pydc)反应,设计合成了2个单核[Ru(Hedta)(4-ptz)]·4H2O(1)和[Ru(Hedta)(2,5-Pydc)]·3H2O(2)配合物。晶体结构解析表明配合物1属于单斜晶系C2/c空间群,晶胞参数为a=2.348 06(15)nm,b=1.301 23(8)nm,c=1.493 08(9)nm,β=101.075 0(10)°;配合物2属于单斜晶系I2/a空间群,晶胞参数为a=3.249 4(7)nm,b=0.966 23(19)nm,c=1.434 1(3)nm,β=93.88(3)°。对2个配合物分别进行了IR及UV-Vis的表征,并通过电子吸收光谱和荧光淬灭光谱研究了配合物与DNA的作用,实验结果表明这2个钌配合物通过插入方式与DNA作用。     

四Schiff碱(二苯并-18-冠-6)及其钾(Ⅰ)/钴(Ⅱ)配合物的合成和性质

由二苯并-18-冠-6出发,合成了4′,4″,5′,5"-四(2-羟基苯亚甲基亚氨基)二苯并-18-冠-6(L1H4)及其5位取代衍生物(取代基R=CH3,OH,OCH3,Cl,NO2)L2H4～L6H4.它们依次与硝酸钾和醋酸钴反应,制得1:1:2的钾(Ⅰ)/双钴(Ⅱ)配合物LCo2·2H2O·KNO3(L=L5,L6)或其某些二氧加合物LCo2(2O2)·2H2O·KNO3(L=L1～L4).考察了取代基R和冠醚环配合的钾离子对二氧加合物形成及稳定性的影响.结果表明,含吸电子基(R=Cl,NO2)的钾(Ⅰ)/双钴(Ⅱ)配合物不能形成二氧加合物;冠环中的钾离子会导致二氧加合物中两个Co-O2键热稳定性的差异.     

草酸根桥联双核配合物[Cd2(phen)2ox(NO3)2·(H2O)2]的合成、结构及态密度分析

通过草酸钾(k2ox·H2O)、硝酸镉[Cd(NO3)2·4H2O]和1,10-邻菲咯啉(phen)在甲醇·水溶液中的反应合成了一种双核镉配合物[Cd2(phen)2ox(NO3)2(H2O)2],其结构经单晶X射线衍射表征.配合物属三斜晶系,P(1)空间群,晶胞参数:a=0.67629(14)nm,b=1.0051(2)nm,c=1.0527(2)nm,α=109.19(3)°,β=92.12(3)°,γ=93.48(3)°,γ=0.6733(2)nm3,Z=1,D=2.055 g/cm3,F(000)=410,μ=1.660mm-1,R=0.0445,wR=0.0877.配合物为草酸根桥联的双核镉配合物,且草酸根C-C键中点为配合物的倒反中心,镉与ox2-,phen,NO3-和水配位.运用晶体场理论计算了其态密度,结果表明NO3-和phen对配合物的性质有重要影响.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Copper catalyzed/mediated synthetic methodology for ebselen and related isoselenazolones

Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.     

Knoevenagel condensation catalyzed by novel Nmm-based ionic liquids in water

A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.     

Construction of polyheterocyclic spirotetrahydrothiophene derivatives via sulfa-Michael/aldol cascade reaction

A series of polyheterocyclic spirotetrahydrothiophene derivatives were obtained in moderate to excellent yields via a catalyst-free sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 under mild conditions. We also present the first asymmetric sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 with moderate to good enantioselectivities catalyzed by readily available chiral phase-transfer catalysts (PTCs).     

Suzuki-Miyaura reactions of the soluble guanylate cyclase inhibitor NS2028: a non-product specific route to C-8 substituted analogues

Both soluble guanylate cyclase (sGC) inhibitors ODQ 1 and NS2028 2 are synthesized via improved protocols. In the former case treating 3,4-dihydroquinoxalin-2(1H)-one oxime 8, which can be prepared in two steps from 1,2-benzenediamine, with 1,1′-carbonyldiimidazole (CDI) gives the dihydro-ODQ 10 that in the presence of KMnO₄ oxidises to give ODQ 1 in an overall yield of 46% starting from 1,2-benzenediamine. In the latter case, the synthesis affords NS2028 2 from 2-amino-4-bromophenol 3 in three steps with an overall yield of 85% and avoids the need for chromatography. Furthermore, Suzuki-Miyaura reaction conditions are described that enable the preparation of 8-aryl and 8-heteroaryl derivatives of NS2028 directly from NS2028 2. Finally, demethylation of the 8-(methoxyphenyl) substituted analogues afforded the 8-(hydroxyphenyl) derivatives 40-42. All new products are fully characterised.