具有抑菌活性的氮杂环铅配合物的合成、结构及构效关系

采用溶液法,在室温条件下合成了2种结构不同的金属铅配合物[Pb(phen)(NO_3)(H_2O)]NO_3(1),[Pb(phen)_2(NO_3)]NO_3(2)(phen=1,10-菲咯啉),并通过元素分析、红外光谱及X射线单晶结构分析对配合物1和2进行了表征。在配合物1中,中心金属Pb(Ⅱ)为四配位,为扭曲的四面体几何构型;在配合物2中,中心金属Pb(Ⅱ)为六配位,形成扭曲的八面体几何构型。配合物1通过分子间氢键形成1D链状超分子结构,而2通过分子间氢键连接形成3D超分子网络结构。配合物1和2对大肠杆菌和金黄色葡萄球菌具有较强抑制作用,配合物2的抑制作用优于配合物1,而且浓度越大,抑制作用越强。     

过渡金属离子与3-氟邻苯二甲酸和1,10-邻菲啰啉配合物的合成、结构及性质

过渡金属离子与3-氟邻苯二甲酸（H₂Fpht）、1,10-邻菲啰啉（phen）通过水热反应得到了5个配合物：[M（Fpht）（phen）（H₂O）₃]·H₂O（M=Ni 1,Co 2）,[Cu（Fpht）（phen）（H₂O）]·H₂O（3）,[M（Fpht）（phen）（H₂O）]·H₂O（M=Zn 4,Cd 5）。通过X-射线单晶衍射分析、元素分析、红外分析、荧光分析以及差热-热重分析对配合物进行了表征。配合物1和2为单核分子,中心离子Ni（Ⅱ）和Co（Ⅱ）与3-氟邻苯二甲酸根的1个氧原子,1,10-邻菲啰啉的2个氮原子以及3个配位水分子的3个氧原子配位,形成六配位的扭曲八面体构型。配合物3为Z字形一维链状结构。中心Cu（Ⅱ）离子与2个3-氟邻苯二甲酸根的2个氧原子,1个1,10-邻菲啰啉的2个氮原子以及水分子的1个氧原子配位,形成四方锥构型。配合物4和5具有相似的一维螺旋结构,中心Zn（Ⅱ）和Cd（Ⅱ）离子与2个3-氟邻苯二甲酸根的3个氧原子、1,10-邻菲啰啉的2个氮原子以及水分子中的1个氧原子配位,形成扭曲的八面体构型。     

杂双金属Cu(Ⅱ)-Nd(Ⅲ)和Zn(Ⅱ)-Ce(Ⅲ)的Salamo型配合物：合成、晶体结构和荧光性质

合成了2个异双核金属Salamo型配合物[Cu（L）Nd（NO₃）₃（C₂H₅OH）]（1）和[Zn（L）（OAc）Ce（NO₃）₂（CH₃OH）]（2）（H₂L=O,O''-（ethane-1,2-diyl）bis（1-（3-ethoxy-2-hydroxyphenyl）-3-ethoxy-2-hydroxybenzaldehyde oxime））,并通过元素分析、红外、紫外、荧光光谱和X射线晶体学对其进行了表征。配合物1是不对称的双核结构,其中Cu（Ⅱ）原子为五配位具有稍微扭曲的四方锥几何构型,而钕（Ⅲ）原子是十配位具有一种扭曲的双帽十二面几何构型。配合物2也是不对称的双核结构,其Zn（Ⅱ）原子为五配位具有一种介于四方锥和三角双锥体之间的几何构型,Ce（Ⅲ）原子为十配位采用了一种扭曲的双面十二面几何构型。与配体相比,在激发波长为318 nm时配合物1发生了荧光淬灭,而配合物2表现出荧光增强。     

3-乙基-2-乙酰吡嗪缩4-苯基氨基脲铜/锌配合物的晶体结构及荧光性质

合成了配合物[Cu（HL）（H₂O）（NO₃）]NO₃（1）和[Zn（HL）Cl₂]（2）（HL为3-乙基-2-乙酰吡嗪缩4-苯基氨基脲）,并通过单晶X射线衍射、元素分析及红外光谱表征了结构。单晶衍射结果表明,配合物1中,中心Cu（Ⅱ）离子与1个中性三齿缩氨基脲配体,1个水分子和1个硝酸根配位,配位构型为扭曲的四方锥。配合物2中Zn（Ⅱ）离子周围的配位原子为N₂OCl₂,其配位构型与配合物1中Cu（Ⅱ）离子的相同。甲醇溶液中,配合物2的荧光发射峰与配体HL相似。而配合物1由于配体和金属离子之间的能量转移,最大荧光发射峰略有红移。     

3-乙基-2-乙酰吡嗪缩N(4)-(对甲苯)氨基硫脲Ga(Ⅲ)、In(Ⅲ)配合物的合成、晶体结构和DNA结合性质

以3-乙基-2-乙酰吡嗪N（4）-（对甲苯）氨基硫脲（HL）为原料,合成了[Ga（L）₂]NO₃·4CH₃OH（1）和[In（L）₂]NO₃·1.75CH₃OH（2）两种新型配合物,并进行了X射线衍射分析表征。结果表明,配合物1和配合物2同构但具有不同数目的结晶甲醇分子。每个配合物的金属中心被2个拥有[N₂S]供体的配体阴离子包围,采取扭曲的八面体配位几何。此外,荧光光谱表明配合物与DNA的相互作用强于配体。     

3-乙基-2-乙酰吡嗪缩4-苯基氨基脲铜/锌配合物的晶体结构及荧光性质

合成了配合物[Cu（HL）（H₂O）（NO₃）]NO₃（1）和[Zn（HL）Cl₂]（2）（HL为3-乙基-2-乙酰吡嗪缩4-苯基氨基脲）,并通过单晶X射线衍射、元素分析及红外光谱表征了结构。单晶衍射结果表明,配合物1中,中心Cu(Ⅱ)离子与1个中性三齿缩氨基脲配体,1个水分子和1个硝酸根配位,配位构型为扭曲的四方锥。配合物2中Zn(Ⅱ)离子周围的配位原子为N₂OCl₂,其配位构型与配合物1中Cu(Ⅱ)离子的相同。甲醇溶液中,配合物2的荧光发射峰与配体HL相似。而配合物1由于配体和金属离子之间的能量转移,最大荧光发射峰略有红移。     

酰胺型配体铜、锌、银配合物的合成、结构及荧光性质

合成并通过单晶衍射表征了5个配合物[CuLCl₂]·CH₃COCH₃（1）、[ZnLCl₂]·CH₃COCH₃（2）、[ZnL（NO₃）₂]·0.5CH₃COCH₃（3）、[AgL₂]ClO₄（4）和[AgL₂]BF₄（5）（L=2-（5-氯-8-喹啉氧基）-1-（吡咯烷-1-基）乙酮）。配合物1和2同构,五配位的中心金属离子采取扭曲的四方锥配位构型,与来自配体L的2个氧原子和1个氮原子及2个氯离子配位。而在配合物3中,锌离子与1个三齿配位的配体L,1个单齿配位的硝酸根和1个双齿配位的硝酸根配位,配位构型为扭曲的八面体。配合物4和5中,中心金属与配体的比例为1∶2。银离子与2个三齿配位的配体L配位,采取扭曲的八面体配位构型。乙腈溶液中,配合物1、2、4和5在410 nm处的最大荧光发射峰与配体L相似。而配合物3由于配体到锌离子之间的能量转移,最大荧光发射峰红移至430 nm。     

喹啉氧基乙酰胺型配体镉配合物的合成、晶体结构及荧光性质

合成并通过单晶衍射表征了一个配合物[CdL(H₂O)(NO₃)]NO₃·CH₃COCH₃ (1)(L=N-甲基N-苯基-2-(8-喹啉氧基)乙酰胺)。在配合物1中,金属镉离子采取扭曲的八面体配位构型。来自配体L的1个氧原子和2个氮原子,2个硝酸根的2个氧原子及配位水分子的1个氧原子与中心镉离子配位。配合物通过分子间的O-H…O氢键作用构筑成沿a轴的一维链状结构。乙腈溶液中配体L和配合物1均在390 nm有荧光发射,但配合物的荧光强度要远低于配体。     

喹啉氧基乙酰胺型配体镉配合物的合成、晶体结构及荧光性质

合成并通过单晶衍射表征了一个配合物[CdL(H₂O)(NO₃)]NO₃·CH₃COCH₃ (1)(L=N-甲基N-苯基-2-(8-喹啉氧基)乙酰胺)。在配合物1中,金属镉离子采取扭曲的八面体配位构型。来自配体L的1个氧原子和2个氮原子,2个硝酸根的2个氧原子及配位水分子的1个氧原子与中心镉离子配位。配合物通过分子间的O-H…O氢键作用构筑成沿a轴的一维链状结构。乙腈溶液中配体L和配合物1均在390 nm有荧光发射,但配合物的荧光强度要远低于配体。     

喹啉-2-甲醛缩4-氟苯基氨基硫脲Cd（Ⅱ）/Fe（Ⅲ）配合物的合成、晶体结构和DNA结合性质

合成并通过单晶衍射、元素分析、红外光谱表征了配合物[Cd₂（L）₂（NO₃）₂]（1）、[Fe （L）₂]NO₃·3CH₃OH （2）和配体硝酸盐（H₂L） NO₃（HL=喹啉-2-甲醛缩4-氟苯基氨基硫脲）。单晶衍射结果表明,双核配合物1中,每个Cd（Ⅱ）离子与一个N₂S供体L^-、一个双齿配位的硝酸根和相邻缩氨基硫脲配体的μ₂-桥联S原子配位,采取扭曲的八面体配位构型。配合物2中,Fe（Ⅲ）离子与来自2个三齿配体L^-的4个N原子和2个S原子配位,同样采取扭曲的八面体配位构型。荧光光谱、紫外光谱以及粘度实验结果表明,配合物2与ct-DNA的结合模式为插入的结合方式,而配体HL和配合物1与ct-DNA以沟面结合的方式相互作用,且配合物2与ct-DNA的结合能力优于配体和配合物1。另外,细胞毒理实验结果表明3种化合物中配合物2具有最强的抑制HeLa肿瘤细胞增殖能力。     

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.