基于{Mo_6O_(19)}簇构筑的1D链状化合物的合成及结构研究

利用水热工艺,选用有机配体3,3',5,5'-四甲基-4,4'-联邻二氮杂茂(H_2X)和CuCl_2·2H_2O为起始原料,合成了1个新的多酸基杂化化合物[Cu_2(H_2X)_2(Mo_6O_(19))]·2H_2O被合成.采用X-射线单晶衍射、红外光谱、元素分析和热重分析等手段对该化合物的结构进行了表征.单晶测试结果表明该化合物为1D链状化合物,属于三斜晶系,P-1空间群,晶胞参数a=0.946 9(3) nm,b=0.954 4(3) nm,c=2.059 9(6) nm,α=90.717(4)°,β= 93.518(5)°,γ=102.802(4)°,V=1.811 2(9) nm~3,Z=4,R1=0.082 9,wR_2=0.151 2.     

一例单缺位Dawson型多酸稀土衍生物的合成、结构及荧光性能研究

在常规水浴条件下成功合成了一例基于单缺位Dawson型二聚的多酸基稀土衍生物[TMA]_8[Tb(H_2O)_8]H_3[Tb(H_2O)_2P_2W_(17)O_(61)]_2·49H_2O (1),并对其进行了红外、X射线单晶衍射等结构表征以及荧光性能研究.X射线单晶衍射结构分析表明,该化合物属于三斜晶系,P-1空间群.其晶胞参数为a=1.313 76(3)nm,b=1.814 70(5) nm,c=1.990 26(6) nm,α=93.549 0°,β=97.273 0(10)°,γ=96.656 0(10)°,Z=1,Mr=10 461.62,V=4.660 9(2) nm~3,μ=22.528 mm~(-1),R_1=0.033 7,wR_2=0.067 0 [I>2σ(I)].此外,化合物1具有Tb~(3+)离子本征荧光发射峰.     

对氨基苯甲酸共价修饰的杂多钼酸盐的合成、结构及性质

以(NH_4)_6Mo_7O_(24)·4H_2O为基本原料,与对氨基苯甲酸、亚磷酸、CsCl在常规水溶液中反应,合成了一例新型杂多钼酸盐Cs_(2.5)H_(2.5)[HPMo_6O_(21)(O_2CC_6H_4NH_2)_3]·7H_2O(1),通过X射线单晶衍射、元素分析、红外光谱、紫外光谱和荧光光谱等方法对该化合物进行了结构表征和性质研究.X射线单晶衍射分析表明,化合物1属于三斜晶系,P-1空间群,晶胞参数a=1.177 46(7)nm,b=1.249 69(8)nm,c=1.880 99(12)nm,α=73.715 0(10)°,β=85.432 0(10)°,γ=84.061 0(10)°.化合物1阴离子结构中包含一个{PMo6}结构单元,并且三个对氨基苯甲酸共价修饰在{PMo6}框架上;紫外光谱分析结果表明,化合物1在水溶液中5 h内相对稳定,荧光光谱的结果表明化合物1存在配体发射.     

以[As_2W_(19)O_(67)(H_2O)]~(14-)单元和Ce~(3+)构筑的二聚的砷钨酸盐的合成、结构及表征

以介稳态的K_(1 4)[As_2W_(19)O_(67)(H_2O)]为多酸前驱体与Ce Cl_3·6H_2O和2,6-吡啶二羧酸反应,采用常规水溶液合成法制得了二聚的且保持多酸前驱体[As_2W_(19)O_(67)(H_2O)]~(14-)结构骨架的多酸基稀土衍生物K_(14)H_8{Ce(H_2O)_3[As_2W_(19)O_(67)(H_2O)]}_2·48H_2O(1),并测定了其晶体结构.同时,通过红外光谱以及热分析对其进行了表征.X射线单晶结构分析表明,化合物1属于三斜晶系,P-1空间群,晶胞参数为a=1.241 13(5)nm,b=1.842 15(8)nm,c=2.193 97(9)nm,α=69.966 0(10)°,β=77.803 0(10)°,γ=77.926 0(10)°,Z=1,M_r=11 125.90,V=4.554 9(3)nm~3,μ=25.519 mm~(-1),R_1=0.045 9,wR_2=0.117 2[I2σ(I)].化合物1是二聚结构,其中Ce~(3+)离子采用八配位畸变的双加冠三棱柱配位构型.     

基于2-(2-呋喃基)咪唑[4,5-f]1,10-邻菲罗啉配体的Cd(Ⅱ)配合物的合成以及晶体结构

本文基于邻菲罗啉衍生物2-(2-呋喃基)咪唑[4,5-f]1,10-邻菲罗啉(L)分别与戊二酸(GLA)和己二酸(ADA)为配体,水热条件下合成配合物[Cd_3(OOC(CH_2)_3COO)_3(C_(17)N_4O_1H_(10))_2]_n(1)和[Cd_3(OOC(CH_2)_4COO)_3(C_(17)N_4O_1H_(10))_2]_n(2),经元素分析、X-射线单晶衍射、红外光谱、热重和荧光进行表征。化合物1属于三斜晶系,空间群p-l,晶胞参数a=8.3633(16),b=10.240(2),c=14.948(3),α=97.598(3)°,β=103.276(3)°,γ=109.053(3)°,Z=2;化合物2属三斜晶系,空间群p-l,晶胞参数a=8.583(3),b=10.332(3),c=15.038(5),α=98.558(4)°,β=105.521(5)°,γ=107.308(5)°,Z=2。晶体1和2配位方式相似,Cd(1)都为七配位,被来自L分子中的两个N原子和GLA(或ADA)中的五个O所包围,中心Cd(2)是与GLA(或ADA)中六个O原子配位,结果导致Cd中心展示为畸形八面体几何晶体结构,并对化合物1进行自然键轨道(NBO)分析(CCDC:1:1559551;2:1559550)。     

一种新型钼钒多酸化合物的合成、结构与荧光性能

采用水热技术,合成了一种新型四帽Keggin结构多酸化合物[H_3Mo_8~ⅥV_8~ⅣO_(40)(AsO_4)](en)_2(4,4-bipy)_7·9H_2O(en:乙二胺;bipy:联吡啶)(1),并对化合物进行了元素分析、红外光谱、X射线光电子能谱和X射线单晶结构分析。晶体结构分析表明,化合物属三斜晶系,P1空间群,晶胞参数a=1.47395(5)nm,b=1.48172(6)nm,c=1.62881(7)nm,α=66.16(3)°,β=87.15(2)°,γ=63.42(1)°,V=2.8723(2)nm3,Z=1,R1=0.0728,w R_2=0.2014。化合物由四帽Keggin多酸阴离子、4,4'-联吡啶、乙二胺和结晶水分子构成,化合物分子间存在大量的氢键,使化合物1形成3-D超分子结构。荧光测试表明,化合物1能发出较强的荧光,有可能成为潜在的光活性材料。     

[2,4—CH3）2C5H5]2TiCO的合成及结构

合成了开环夹心羰基化合物[2,4-(CH_3)_2C_5H_5]_2GCO,得到了该分子的单晶结构,[2,4-(CH_3)_2C_5H_5]_2TiCO晶体属于正交晶系,P2_12_12_1空间群,晶胞参数a=1.0078(5)nm,b=1.1909(8)nm,c=1.1946(5)nm,b=1.4337(13)nm~3,Z=4,R=0.054。单晶结构表明该分子为平行覆盖型开环夹心化合物,用EHMO方法计算了[2,4-(CH_3)_2C_5H_6]_2TICO的电子结构。     

基于[As_2W_(19)O_(67)(H_2O)]~(14-)构筑的含镧砷钨酸盐的合成和结构表征

通过水热法合成了一例[As_2W_(19)O_(67)(H_2O)]~(14-)({As_2W_(19)})构型保持的稀土衍生物K_(14)H_8[La(H_2O)_3As_2W_(19)O_(67)(H_2O)]_2·53H_2O(1),并测定了其晶体结构.同时,通过红外光谱、粉末衍射(XRPD)以及热分析对其进行了表征.X射线单晶结构分析表明,化合物1属于三斜晶系,P-1空间群,晶胞参数为a=1.239 5(10)nm,b=1.847 8(16)nm,c=2.268 5(19)nm,α=68.366(12)°,β=78.215(13)°,γ=78.406(12)°,Z=1,Mr=11 351.63,V=4.683(7)nm3,μ=24.794mm-1,R1=0.056 4,wR2=0.150 8[I2σ(I)].化合物1是二聚结构,其中LaIII离子采用九配位畸变的单加冠四方反棱柱配位构型.     

基于{PMo_(12)O_(40)(VO)_(0.5)}的Cu(Ⅰ)配合物的合成及荧光性质研究

利用磷钼十二酸、偏钒酸铵、CuCl_2·2H_2O和3,3′,5,5′-四甲基-4,4′-联邻二氮杂茂(H_2X)在水热条件下反应,合成出了1个新的多酸基杂化化合物Cu_4(H_2X)_4[(PMo_(12)O_(40)(VO)_(0.5))].通过X射线单晶衍射、红外光谱和热重分析等测试手段对该化合物进行了结构表征.单晶结构解析表明该化合物为2D层状化合物,属于单斜晶系,C2/c空间群,晶胞参数a=2.637 6(5)nm,b=1.542 2(5)nm,c=2.057 0(5)nm,α=90.000(5)°,β=112.677(5)°,γ=90.000(5)°,V=7.720(3)nm~3,Z=4,R_1=0.061 5,wR_2=0.164 6.     

两种钴离子支撑钼磷多金属氧酸盐的水热合成及晶体结构

利用水热技术合成了2个新型钴支撑的磷钼多金属氧酸盐超分子化合物:(C2N2H10)5[(P4Mo6O25(OH)6)2Co](1)和(Co(H2O)6)2(C5NH6)6[(P4Mo6O25(OH)6)2Co]·10H2O(2).并通过元素分析、红外光谱、热重分析和X射线单晶衍射对2个化合物进行了表征.结果表明:化合物1属于三斜晶系,P-1空间群;晶胞参数a=1.179 9(2)nm,b=1.337 7(2)nm,c=1.479 7(3)nm,α=73.435(2)°,β=74.383(2)°,γ=66.499(2)°,V=2.020 5(6)nm3,F(000)=1 327,Z=1;化合物2属于属于三斜晶系,P-1空间群;晶胞参数a=1.220 68(11)nm,b=1.381 08(13)nm,c=1.687 18(15)nm,α=92.275(1)°,β=104.774(1)°,γ=114.475(1)°,V=2.468 8(4)nm3,F(000)=1 649,Z=1.     

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.     

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.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.     

Catalyst free,visible-light promoted photoaddition reactions between C60 and N-trimethylsilylmethyl-substituted tertiary amines for synthesis of aminomethyl-1,2-dihydrofullerenes

An efficient and benign method for the preparation of aminomethyl-substituted fullerenes has been developed. The process, involving catalyst free, visible-light irradiation of 10% EtOH-toluene solutions containing fullerene C₆₀ and N-trimethylsilylmethyl-substituted amines by using a 20 W compact fluorescent lamp, leads to formation of aminomethyl-substituted fullerene adducts in a highly efficient manner. The photoaddition reaction takes place via a pathway initiated by visible light absorption by C₆₀, followed by SET from the amine to the triplet excited state of C₆₀. Ethanol-promoted desilylation of the resulting a minimum radical then generates the corresponding α-amino radical which couples with the C₆₀ radical anion to form the anion precursor of the fullerene adducts. The new approach using visible-light takes place under mild conditions and it does not require the use of photocatalysts. Thus, the method developed in this effort could broadens the range of functionalized fullerene derivatives that can be readily prepared.     

Highly efficient and stereoselective cycloaddition of nitrones to indolyl- and pyrrolylacrylates

The reactions of various nitrones with indolyl- and pyrrolylacrylates proceeds regioselectively with high diastereoselectivity in the case of aldonitrones, and represents an effective method for obtaining new indolyl- and pyrrolyl-substituted isoxazolidine carboxylates stabilized by weak (CH?O) and moderate (NH?N) strength intramolecular hydrogen bonding. The resulting cycloadducts exhibit promising in vitro anti-influenza activities.     

Transition metal-free direct amination of benzoxazoles using formamides as nitrogen sources

A transition metal-free method for the direct amination of benzoxazoles using formamides as nitrogen sources is reported, which was mediated by an inexpensive and environmentally friendly tetrabutylammonium iodide/tert-butyl hydroperoxide system and gave the 2-aminobenzoxazole derivatives with moderate to good yields.     

l-Proline-catalyzed five-component domino reaction leading to multifunctionalized 1,2,3,4-tetrahydropyridines

Multifunctionalized 1,2,3,4-tetrahydropyridines are concisely synthesized in good yields via l-proline-catalyzed or l-proline/FeCl₃-cocatalyzed one-pot multicomponent reactions (MCRs). The MCRs involve a domino hydroamination/prins reaction/Mannich-type reaction/intramolecular dehydration-cyclization process. The molecular structure of 5baa, one of multifunctionalized 1,2,3,4-tetrahydropyridines, was confirmed by single-crystal X-ray diffraction.     

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.