三种配合物微晶的尺寸可控合成及其光催化性质（英文）

以4,4′-二苯醚二甲酸和4,4′-联吡啶为配体,通过调节水热反应的条件,如三乙胺的加入量,反应时间和反应温度等因素,可控合成了尺寸从10到250μm的Ni(Ⅱ)、Co(Ⅱ)和Zn(Ⅱ)3种配合物微晶,其尺寸、形貌和结构用扫描电镜和X射线粉末衍射进行了表征和分析。光催化性能测试表明3种配合物对有机染料罗丹明B、甲基橙和亚甲基蓝均具有杰出的降解能力,且随着配合物晶粒尺寸减小其催化能力明显提高。最引人注目的是尺寸为30μm的Ni(Ⅱ)配合物,其光催化性降解Rh B染料的能力已超越纳米TiO_2。此外,X射线粉末衍射表明,在一次光降解过程后配合物结构保持稳定,可作为重复利用的光催化剂。     

铜三氟柳配合物的合成,结构和仿生催化溴化

合成了一系列2-羟基-4-三氟甲基苯甲酸（h₂tba）-铜配合物：[Cu（htba）₂（pz）₂] （1）,[Cu（htba）（2,2''-bipy）]（htba） （2）和[Cu（htba）₂（4,4''-bipy）] （3）（h₂tba=2-羟基-4-三氟甲基苯甲酸,pz=吡唑,2,2''-bipy=2,2''-联吡啶,4,4''-bipy=4,4''-联吡啶）,并且通过元素分析、红外光谱、紫外光谱、粉末X射线衍射、单晶X射线衍射和热重分析方法对配合物结构进行了表征。这些配合物能够在过氧化氢和溴化物存在的条件下催化苯酚红溴化,并且展示出了较高的催化溴化活性。     

铜三氟柳配合物的合成,结构和仿生催化溴化

合成了一系列2-羟基-4-三氟甲基苯甲酸（h₂tba）-铜配合物：[Cu（htba）₂（pz）₂]（1）,[Cu（htba）（2,2''-bipy）]（htba）（2）和[Cu（htba）₂（4,4''-bipy）]（3）（h₂tba=2-羟基-4-三氟甲基苯甲酸,pz=吡唑,2,2''-bipy=2,2''-联吡啶,4,4''-bipy=4,4''-联吡啶）,并且通过元素分析、红外光谱、紫外光谱、粉末X射线衍射、单晶X射线衍射和热重分析方法对配合物结构进行了表征。这些配合物能够在过氧化氢和溴化物存在的条件下催化苯酚红溴化,并且展示出了较高的催化溴化活性。     

以4,4’-联苯咪唑及间苯二甲酸根为配体构筑的Ni(Ⅱ)配位聚合物的合成、晶体结构及光学性质

以4,4'-联苯咪唑(4,4'-bibp)和间苯二甲酸(H₂MPA)为配体,采用水热法合成了1个二维镍(Ⅱ)配位聚合物[Ni(H₂O)(MPA)(4,4'-bibp)]_n(1)。通过元素分析、红外光谱、热重(TGA)和X-射线粉末衍射(PXRD)等手段对其进行了表征,并用X-射线单晶衍射法测定了配合物的单晶结构。该配合物属于单斜晶系,Pc空间群,为二维层状结构。我们研究了配体和配合物在室温下的固体紫外光谱性质。     

基于5-羟甲基间苯二甲酸和咪唑衍生物的半导体型Ni-MOFs的合成、晶体结构和光催化性质

利用水热反应制备了2个配合物{[Ni （HIPA）（2,5-DPBI）_1.5（H₂O）]·2.25H₂O}_n （1）和[Ni （HIPA）（2,5-DPBMI）（H₂O）]_n （2）（H₂HIPA=5-（羟甲基）间苯二甲酸,2,5-DPBI=1,1''-（2,5-二甲基-1,4-亚苯基）双（1H-咪唑）,2,5-DPBMI=1,1''-（2,5-二甲基-1,4-亚苯基）双（4-甲基-1H-咪唑））。结构分析揭示在不同咪唑配体存在下,配合物的Ni（Ⅱ）中心具有不同的配位环境。配合物1具有拓扑符号为（4².6⁶.8²）的五连接三维框架,而配合物2则是dia型的四连接网络。粉末X射线衍射证实配合物1和2在有机溶剂和紫外可见光照射的水中均非常稳定。此外,紫外可见吸收谱、Mott-Schottky和电化学阻抗谱（EIS）测试显示配合物1和2都是典型的n型半导体材料,具有较低的电荷传输阻抗。在光催化实验中,配合物1和2对染料亚甲基蓝的降解有催化活性。     

基于5-(4-羟基吡啶基甲基)间苯二甲酸配体的两种Zn(Ⅱ)的配位聚合物的合成、结构和荧光性质

采用水热合成的方法,在以5-（4-羟基吡啶基甲基）间苯二甲酸（H₂L）作主配体、4,4’-联吡啶（4,4’-bpy）和1,2-二（4-吡啶基）乙烯（bpe）作辅配体的条件下,得到2种新颖的Zn（Ⅱ）配位聚合物{[Zn（L）（4,4’-bpy）_0.5]·2H₂O}_n（1）和{[Zn（L）（bpe）_0.5]·2H₂O}_n（2）。配合物通过单晶X射线衍射的方法进行了结构分析,并进一步通过红外光谱（IR）、元素分析、PXRD和热重分析（TG）的方法进行了表征。结构分析表明配合物1展现出的是一种三维三重互穿网络;聚合物2为二维双层结构,并进一步组合成了三重平行互穿的2D→3D的空间网络。此外,研究了配合物的荧光性质。     

Ag负载CdMoO4光催化剂的制备及其催化性能

采用硼氢化钠还原法制备了Ag负载CdMoO₄光催化剂。运用X射线粉末衍射（XRD）、扫描电镜（SEM）和透射电镜（TEM）等测试手段对催化剂的组成和结构进行了表征;采用紫外-可见漫反射光谱（UV-Vis DRS）和X射线光电子能谱（XPS）等技术对催化剂的光响应和表面状态进行了分析,考察了不同Ag负载量对CdMoO₄紫外光降解罗丹明B和可见光选择性氧化苯甲醇性能的影响。结果表明,与CdMoO₄相比,Ag/CdMoO₄具有更高的光催化活性。利用活性物种捕获实验探讨其光催化降解过程的反应机理,实验结果显示O₂^-·和·OH是光催化降解过程的主要活性物种。     

基于柔性多羧酸配体H3TCOPM构筑的Co(Ⅱ)配合物的合成与结构

以三苯甲烷-4,4’,4"-三羧酸（H₃TCOPM）为主配体,以含氮二齿配体4,4’-bipyridine（4,4’-bipy）为辅助配体,与Co（NO₃）₂·6H₂O通过溶剂热反应得到了2个配位聚合物{[Co₂（α-OH-TCOPM）（OH）（H₂O）₄]·DMF}_n（1）（α-OH-H₃TCOPM=三苯甲醇-4,4’,4"-三羧酸）和{[Co₃（α-OH-TCOPM）₂（4,4’-bipy）₃（H₂O）₆]·2H₂O}_n（2）。晶体结构分析表明,配合物1为四边形的二维层状结构,而配合物2为二维网状结构。采用红外光谱、粉末X射线衍射对配合物进行了表征,用热重分析仪研究了其热稳定性。     

基于四氮唑的Cu(Ⅰ)/Cu（Ⅱ）配合物及其可见光催化降解有机污染物

利用1,2,4,5-四（2H-四氮唑）苯配体（H4TTB）和三苯基磷（PPh₃）与氰化亚铜在水热/溶剂热条件下的反应得到一价铜配合物[Cu₂（TTB）_0.5（PPh₃）]_n （1）和二价铜配合物{[Cu（TTB）_0.5（H₂O）₂]·H₂O}_n（2）,并通过红外光谱、热稳定性分析和X-射线粉末衍射对它们进行了表征。X射线单晶结构解析表明,1中的每个TTB^4-配体都有12个N原子参与配位,进而使得配合物1拥有了二维的骨架结构,而配合物2则呈现出一维双Cu²⁺链结构。这两个配合物在可见光照射下对罗丹明B（RhB）和亚甲基蓝（MB）都表现出很好的催化降解性能：氙灯照射1 h,一价铜配合物1和二价铜配合物2对RhB的降解率分别达到了88%和78%;而这两个配合物对MB的降解效果更好,在40 min后都达到了93%,这也说明一价铜配合物和二价铜配合物都能有效的光催化降解有机染料。     

基于不对称三氮唑衍生物配体的三个配合物的制备、晶体结构及光催化性能

利用水热法合成了基于不对称三氮唑衍生物配体Hptp（Hptp=2-（5-（pyridin-3-yl）-1H-1,2,4-triazol-3-yl）pyrazine）的3个配合物[Cd₂（ptp）₂（SO₄）（H₂O）₂]_n（1）、[Zn（ptp）₂（H₂O）₂]（2）和[Cd（ptp）₂（H₂O）₂]（3）,它们的结构通过元素分析,红外,粉末X射线衍射和X射线单晶衍射表征。配合物1中,配体ptp^-和Cu²⁺形成波浪状的一维结构,这些一维链通过SO₄^2-链接形成三维结构。配合物2和3是同构化合物,单核单元在分子间氢键的作用下形成超分子二维平面。光催化降解实验表明,在双氧水存在时配合物1~3在60 min内使亚甲基蓝的降解率分别达到79%、81%和88%。     

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%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.