基于N-乙酸基-5-氧烟酸的两个Pb（Ⅱ）配位聚合物的合成、晶体结构与荧光性质

采用水热法合成了2个以N-乙酸基-5-氧烟酸（H₂L）为配体的铅金属-有机配位聚合物：[Pb₄（μ₃-O）₂L₂]_n（1）和[Pb₃（μ₄-O）₂L]_n（2）。通过元素分析、红外光谱和X射线单晶衍射进行了结构表征。结构分析表明,聚合物1属单斜晶系,C2/c空间群,其由[Pb₄（μ₃-O）₂]_n构成的刚性无机链通过配体L^2-连接成三维网络结构。聚合物2属正交晶系,P2₁2₁2₁空间群,其三维结构由[Pb₃（μ₄-O）₂]_n构成的无机金属链与配体L^2-相互连接形成。研究了2的热稳定性及其在室温下的固体荧光性质。     

以3,5-二（吡啶-4-甲氧基）苯甲酸为配体构筑的两个钡（Ⅱ）、铅（Ⅱ）配位聚合物

以3,5-二（吡啶-4-甲氧基）苯甲酸（HL）为配体合成了2个配合物：[BaL₂]_n（1）和[PbL（Ox）_0.5]_n（2）（H₂（Ox）为草酸）,并通过元素分析,红外光谱,热重和X-射线单晶衍射实验对其结构进行了表征。分析表明,1由L^-连接形成二维结构,通过苯环之间的π…π作用连接成三维网络结构;2由于主配的连接形成二维层状结构,再通过辅配连接形成拓扑符号为（4³）（4⁴.5.6¹⁷.7².8²）（4.5²）的三维网络结构。     

联苯-2,4,4',6-四甲酸银、咪唑-菲啰啉-苯氧乙酸镉配位聚合物的合成、结构及与DNA的相互作用

由联苯-2,4,4'',6-四甲酸（H₄BPTC,C₁₆H₁₀O₈）和2-4-（1H-咪唑-2-[4,5-f] [1,10]菲啰啉基）苯氧乙酸（HPIMPHC,C₂₁H₁₄N₄O₃）,水热合成了2种新型配位聚合物[Ag₄（BPTC）]_n（1）,[Cd（PIMPHC）₂]_n（2）。用元素分析、红外光谱、热重分析和X射线单晶衍射对配合物进行了表征和结构分析。配合物 1 属三斜晶系,空间群为P1;Ag（Ⅰ）的配位数分别为4、3、2,配位构型为变形四面体、平面三角形和V型。配合物2属正交晶系,空间群为Pbcn;Cd（Ⅱ）的配位数为6,配位构型为变形的八面体,Cd（Ⅱ）离子间通过三齿配体 PIMPHC^-桥连,形成2D网状结构。用EtBr荧光探针法研究了配体及配合物与ct-DNA的相互作用。     

咪唑-菲咯啉-苯氧乙酸锌、铅配合物的合成,结构及与DNA的相互作用

以2-4-(1H-咪唑-2-[4,5-f] [1,10]菲咯啉基)苯氧乙酸(HPIMPHC)和2-2-(1H-咪唑-2-[4,5-f] [1,10]菲咯啉基)苯氧乙酸(HOIMPHC)为配体,水热合成了2种新型配合物[Zn(PIMPHC)₂]_n (1)和{[Pb(OIMPHC)₂]·4H₂O}_n (2)。配合物1属正交晶系,空间群为Pbcn;Zn(Ⅱ)的配位数为6,配位构型为变形的八面体,形成2D网状结构。配合物2属单斜晶系,空间群为P2₁/n;Pb(Ⅱ)的配位数为7,配位构型为变形的五角双锥,形成2D网状结构。荧光光谱的结果表明,配合物与DNA的相互作用强于配体。     

两个基于β-二酮配体构筑的银配位聚合物的合成和晶体结构

以配体3-（（5-（3-吡啶基）-2-（1,3,4-噁二唑基））硫代）-2,4-戊二酮（L₁）与AgSbF₆进行配位反应,得到配位聚合物{[Ag（L₁）₂]SbF₆}_n （1）;以配体3-（（5-（4-吡啶基）-2-（1,3,4-噁二唑基））硫代）-2,4-戊二酮（L₂）与AgCF₃SO₃进行配位反应,得到配位聚合物[Ag（L₂）（CF₃SO₃）]_n （2）。并通过粉末X射线衍射、红外光谱、元素分析和单晶X射线衍射对配合物的结构进行了表征。在固体状态下,配位聚合物1和2都形成1D链状结构。     

基于反-双(β-二酮)-1,4-环己二胺的席夫碱Hg(II)配位聚合物的合成与晶体结构

合成了反1,4-环己二胺桥联β-二酮的席夫碱配体L1（反-双（乙酰丙酮）-1,4-环己二胺）和L2（反-双（苯甲酰丙酮）-1,4-环己二胺）,然后将配体L1和L2分别与HgCl₂、HgI₂进行配位反应,得到4个Hg（Ⅱ）配合物：[Hg₂（L1）Cl₄]_n（1）,{[Hg₂（L2）Cl₄]·L2}_n（2）,[Hg₂（L1）I₄]_n（3）,[Hg₂（L2）I₄]_n（4）。并通过元素分析、红外光谱、粉末衍射、单晶X射线衍射等对配合物的结构进行了表征。在固体状态下,配合物1和2的Hg（Ⅱ）离子与配体中的γ-C原子及3个氯离子配位形成1D链结构,配合物3的Hg（Ⅱ）离子与L1配体中的烯醇式氧原子,以及3个碘离子配位形成2D网状结构,配合物4的Hg（Ⅱ）离子与配体L2中的烯醇式氧原子及3个碘离子配位形成1D链结构。     

基于反-双(β-二酮)-1,4-环己二胺的席夫碱Hg(Ⅱ)配位聚合物的合成与晶体结构

合成了反1,4-环己二胺桥联β-二酮的席夫碱配体L1（反-双（乙酰丙酮）-1,4-环己二胺）和L2（反-双（苯甲酰丙酮）-1,4-环己二胺）,然后将配体L1和L2分别与HgCl₂、HgI₂进行配位反应,得到4个Hg（Ⅱ）配合物：[Hg₂（L1）Cl₄]_n（1）,{[Hg₂（L2）Cl₄]·L2}_n（2）,[Hg₂（L1）I₄]_n（3）,[Hg₂（L2）I₄]_n（4）。并通过元素分析、红外光谱、粉末衍射、单晶X射线衍射等对配合物的结构进行了表征。在固体状态下,配合物1和2的Hg（Ⅱ）离子与配体中的γ-C原子及3个氯离子配位形成1D链结构,配合物3的Hg（Ⅱ）离子与L1配体中的烯醇式氧原子,以及3个碘离子配位形成2D网状结构,配合物4的Hg（Ⅱ）离子与配体L2中的烯醇式氧原子及3个碘离子配位形成1D链结构。     

基于吡啶二羧酸配体的稀土配合物的合成、结构及性质

以2,6-二甲基吡啶-3,5-二羧酸（H₂L₁）为主配体,1,10-菲咯啉（L₂）为辅配体,分别与五水合硝酸镝、六水合硝酸铽及六水合硝酸铕通过水热法合成[Dy₂（L₁）₃（L₂）₂]_n（1）、{[Tb₂（L₁）₃（L₂）₂]·5H₂O}_n（2）和{[Eu₂（L₁）₃（L₂）₂]·5H₂O}_n（3）三种配合物。通过单晶X射线衍射、红外光谱、荧光光谱和热重分析对其结构进行了表征与性质研究。结果表明,配合物1~3均以稀土离子为金属节点连接配体L₁^2-和L₂,形成无限延伸的一维链状结构。     

三个基于柔性4-取代双三唑配体锌配位聚合物的合成、晶体结构

以1,2-二（4H-1,2,4-三唑）乙烷（btre）和3个二元羧酸1,3-金刚烷二酸（H₂adc）、对苯二甲酸（1,4-H₂bdc）和邻苯二甲酸（1,2-H₂bdc）为配体,在室温下合成了3个锌配位聚合物{[Zn（μ₂-btre）（μ₂-adc）]H₂O}_n（1·H₂O）、[Zn₂（μ₂-btre）（μ₂-1,4-bdc）₂（H₂O）₂]_n（2）和[Zn（μ₂-btre）（μ₂-1,2-bdc）]_n（3）。测试了3个配合物的晶体结构,并用红外光谱、元素分析和粉末衍射对其进行表征。晶体结构测试表明,1为2D（4,4）网格结构,π-π作用将相邻的2D网格连接成3D结构。配合物2和3分别是3D和2D（4,4）网格结构。另外,研究了3个配合物的热稳定性和室温下的固体荧光。     

基于N-((3-吡啶基)磺酰基)天冬氨酸的Co(Ⅱ)、Zn(Ⅱ)、Cd(Ⅱ)配位聚合物的合成、磁性和荧光性质

以N-（（3-吡啶基）磺酰基）天冬氨酸（H₂L）为配体,采取水热合成的方法,合成了配位聚合物[M（HL）₂]_n （M=Co,1;Zn,2;Cd,3）。X射线单晶衍射分析表明,它们的晶体同构。1的磁性分析表明,1的Curie常数为4.66 cm³·mol^-1·K,Curie-Weiss常数为 -21.23 K;与配体H₂L相比,2和3的发射光谱发生了明显的蓝移,可能归因于配体到金属的电荷转移。     

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.     

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.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.