二维网格结构的新型配位聚合物[Zn(PDA)]n的合成、晶体结构及荧光性质

以2,6-吡啶二酸为配体, 与锌盐通过水热合成法得到具有二维网格结构的新型配位聚合物[Zn(PDA)]n(PDA=2,6-吡啶二羧酸根); 采用红外光谱、元素分析、热重分析及单晶X射线衍射等手段对[Zn(PDA)]n的晶体结构进行了表征. 并进一步研究了[Zn(PDA)]n的荧光性质.     

两例基于相同的含氮及联苯二羧基混合配体构筑的Zn(Ⅱ)/Cd(Ⅱ)配位聚合物:不同的穿插结构和荧光性质（英文）

在溶剂热条件下合成了2个锌(Ⅱ)/镉(Ⅱ)配位聚合物:{[Zn(1,3-bip)(bpdc)]·0.5H2bpdc}n(1),{[Cd2(1,3-bip)2(bpdc)2]·DMF}n(2),H2bpdc=4,4′-联苯二甲酸,1,3-Bip=1,3-二(咪唑基)丙烷。并通过X射线单晶衍射,粉末XRD、红外光谱、元素分析以及热重分析对其结构进行表征。单晶解析结果表明:配位聚合物1是一个五重穿插3D→3D三维空间网络结构,配位聚合物2是一个二重穿插的2D→2D二维的(4,4)网格层状结构。另外,研究了2个配位聚合物在室温下的热稳定和荧光性能。     

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。     

三维配位聚合物[Sr(BDC)(H2O)]的合成、结构与热稳定性

利用溶剂热法在硝酸锶、1,4-对苯二甲酸（BDC）、N,N′-二甲基甲酰胺（DMF）和水体系中合成了一种新的配位聚合物[Sr（BDC）（H₂O）]（1）,并通过单晶X射线衍射、变温粉末X射线衍射、元素分析、红外光谱和热重-质谱联用对其进行了表征.该化合物属正交晶系的Pbca空间群,晶胞参数为a=1.1854（2）nm,b=0.7122（1）nm,c=2.0031（4）nm.该化合物具有三维网络结构,由共面的SrO₈四方反棱柱组成的zigzag链通过1,4-对苯二甲酸配体连接而成.热重-质谱联用和变温粉末X射线衍射分析表明它的骨架具有较高的热稳定性。     

两例基于相同的含氮及联苯二羧基混合配体构筑的ZnⅡ/CdⅡ配位聚合物:不同的穿插结构和荧光性质

在溶剂热条件下合成了2个锌Ⅱ/镉Ⅱ配位聚合物：{[Zn（1,3-bip）（bpdc）]·0.5H₂bpdc}_n（1）,{[Cd₂（1,3-bip）₂（bpdc）₂]·DMF}_n（2）,H₂bpdc=4,4''-联苯二甲酸,1,3-Bip=1,3-二（咪唑基）丙烷。并通过X射线单晶衍射,粉末XRD、红外光谱、元素分析以及热重分析对其结构进行表征。单晶解析结果表明：配位聚合物1是一个五重穿插3D→3D三维空间网络结构,配位聚合物2是一个二重穿插的2D→2D二维的（4,4）网格层状结构。另外,研究了2个配位聚合物在室温下的热稳定和荧光性能。     

普鲁士蓝类配位聚合物KCd[Cr(CN)6]·H2O的合成、结构及多孔性能研究

以Cd2 和[Cr(CN)6]3-为建筑基元通过自组装合成普鲁士蓝类配位聚合物KCd[Cr(CN)6]·H2O(1·H2O),并用红外光谱、元素分析、单晶X射线衍射、粉末X射线衍射、热重分析和氮气吸附脱附等手段对其进行了表征.配位聚合物1·H2O属于面心立方晶系,空间群Fm-3m,晶胞参数:a=b=c=1.09059mn,α=β=γ=90°.配位聚合物1·H2O是由K ,Cd2 ,[Cr(CN)6]3-离子和一个结晶水分子组成的三维多孔结构.热重分析结果表明失水样品1的骨架结构在120～200℃之间保持稳定.氮气吸附脱附研究表明:失水样品1具有683.6m2·g-1的比表面积,氮气最大吸附量为8.83mmol·g-1.     

两例基于相同的含氮及联苯二羧基混合配体构筑的Zn(Ⅱ)/Cd(Ⅱ)配位聚合物:不同的穿插结构和荧光性质

在溶剂热条件下合成了2个锌Ⅱ/镉Ⅱ配位聚合物：{[Zn（1,3-bip）（bpdc）]·0.5H₂bpdc}_n（1）,{[Cd₂（1,3-bip）₂（bpdc）₂]·DMF}_n（2）,H₂bpdc=4,4''-联苯二甲酸,1,3-Bip=1,3-二（咪唑基）丙烷。并通过X射线单晶衍射,粉末XRD、红外光谱、元素分析以及热重分析对其结构进行表征。单晶解析结果表明：配位聚合物1是一个五重穿插3D→3D三维空间网络结构,配位聚合物2是一个二重穿插的2D→2D二维的（4,4）网格层状结构。另外,研究了2个配位聚合物在室温下的热稳定和荧光性能。     

双咪唑基丁烷及邻苯二甲酸根构筑的镍多孔配位聚合物的合成、结构及性质研究

在水热反应条件下,合成了一种新的镍配位聚合物,[Ni(Pht)(bbim-4)]n(Pht=邻苯二甲酸阴离子,bbim-4=1,4-双(咪唑-1-基)丁烷),经元素分析、粉末X射线衍射、热重和X射线单晶衍射表征了配合物。该配合物属于单斜晶系,空间群C2/c。结构分析表明:该配合物是一个三维的具有三角形孔道的多孔配位聚合物。配位聚合物表现出一个整体上的铁磁行为。77 K温度下,气体吸附研究表明该多孔配位聚合物对N2和CO2气体的吸附具有选择性。     

辅助配体导向合成两个锌金属配位聚合物:结构,稳定性和荧光性质（英文）

以二苯-4,4′-二羧酸和六水硝酸锌为原料,在相同反应条件下,通过改变不同的辅助配体(2,2′-二甲基-4,4′-联吡啶和三乙烯二胺),合成出2个金属有机配位聚合物:{[Zn(DBA)(dmbpy)_(0.5)]·2H_2O}_n(1)和[Zn_2(DBA)_2(dabco)]_n(2)(H_2DBA=二苯-4,4′-二羧酸,dmbpy=2,2′-二甲基-4,4′-联吡啶,dabco=三乙烯二胺)。通过元素分析、红外光谱、差热分析、X射线粉末衍射和X射线单晶衍射等手段对配合物进行了结构表征。结果显示,化合物1为二维(4,4)网络结构,2个二维结构在平行方向上通过互锁进一步形成2D→2D的互锁网络结构。化合物2为一维带状结构。热稳定性表明化合物1能够稳定到370℃;而化合物2稳定性差。荧光分析表明常温固态下配合物1和2均发射蓝色荧光,荧光寿命分别为231.4 ns和2.33 ns。     

两个双核稀土金属配位聚合物的溶剂热合成、晶体结构及荧光性质

以顺丁烯二酰肼(MH)为配体,通过溶剂热法合成了配位聚合物[Dy2(MH)6]n·0.5DMF(1)和[Eu2(MH)6]n(2)。通过红外光谱、X射线粉末衍射、X射线单晶衍射表征了2个晶体的结构。配合物1和2都是三斜晶系,P1空间群。以双核结构为顶点作图得到配合物的空间拓扑结构,拓扑类型为tsi。配合物的热重分析结果表明2个配合物在315℃左右仍有较好的热稳定性。固体荧光结果表明配合物2在激发波长为375 nm时有对应Eu~(3+)的5D0→7FJ(J=0~4)能级能量的5个发射峰,最强发射峰波长为616 nm,归属为Eu~(3+)的5D0→7F2能级跃迁。     

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.     

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%).     

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.     

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.