Ge_(10)O_(28)单元构建的两个三维锗酸盐结构:(H_3O)_4Ge_7O_(16)·3H_2O和K_4Ge_9O_(20)

在半水溶剂热条件下 ,采用不同的合成条件合成了两个锗酸盐微孔分子筛 :(H3O) 4Ge7O16 ·3H2 O和K4 Ge9O2 0 .X射线单晶结构解析表明 ,两个晶体结构具有相同的“火箭状”二级结构单元 (SBU) ,SBU的不同的连接方式导致了完全不同的空间结构 .H4 Ge7O16 ·7H2 O的结晶学数据为Mr=894 2 7,P 43m ,a =0 7730 9( 18)nm ,V =0 462 0 5 ( 19)nm3,Z =1,MoKα ,λ =0 0 710 73nm ,R(F) =3 48% ,wR(F2 ) =8 39% .K4 Ge9O2 0 的结晶学数据为 :Mr=112 9 71,I4( 1) /a ,a =1 5 0 0 2 ( 3)nm ,c =0 7383( 2 )nm ,V =1 6618( 7)nm3,Z =4,MoKα ,R(F) =3 92 % ,wR(F2 ) =11 97% .     

磷酸锗铁铝分子筛的合成与鉴定

在氟离子体系中,合成了磷酸锗铁铝分子筛GeFeAPO-5的纯相,吸附吡啶后的红外光谱表明GeFeAPO-5分子筛中存在Brnsted酸和Lewis酸中心;X射线衍射分析、晶胞参数测定、电子探针、红外光谱、穆斯堡尔谱、电子顺磁共振谱、固体高分辨魔角旋转核磁共振谱等结果表明,锗和铁进入了GeFeAPO-5分子筛骨架。     

三维多立方烷类氯桥连的Cu（Ⅱ）簇合物[Cu3Cl6]∞的水热合成及其晶体结构

立方烷结构的过渡金属簇具有特殊的磁性,催化活性和稳定性等而备受关注[1]。超过7核的立方烷类铜簇化合物已知的甚少,典型的代表有羟基氧桥连的共角二联立方烷类七核铜簇[Cu7(OH)6Cl2(pn)(H2O)2](C(CN)3)4Cl2(pn=1,3 di aminopropane)[2]和[Cu7(bpym)6(OH)8(H2O)2](NO3)6·H2O(bpym=2,2 bipyrimidine)[3]以及烷氧桥连的双立方烷类八核铜簇[Cu8L8(O2CMe)4][ClO4]4(L=di 2 pyridyldetone)[4]等。我们采用水热方法合成了多立方烷类三维的具有开放式骨架的[Cu3Cl6]∞铜簇合物,并用X射线晶体衍射进行了结构表征。1　实验部分1 1…     

二维钨-钒簇聚物[Cu(en)_2]_2·[W_(4.5)~ⅥW_2~ⅤV~ⅤV_(9.5)~ⅣO_(44){Cu(en)_2(H_2O)}_2]·3H_2O的合成与表征

采用水热法合成了一个钨-钒簇聚物[Cu(en)2]2[WⅥ4.5WⅤ2VⅤVⅣ9.5O4 4{Cu(en)2(H2O)}2]·3H2O(1,en=乙二胺),并通过X射线单晶衍射、元素分析、傅里叶变换红外光谱、X射线粉末衍射、热重分析、价键计算、X射线光电子能谱、电子顺磁共振和磁性分析对其结构和性能进行了表征.结果表明,化合物1是以双支撑的四帽Keggin结构[WⅥ4.5WⅤ2VⅣ9.5O4 0(VⅤO4){Cu(en)2(H2O)}2]4-钨-钒簇合物阴离子为基本结构单元,与4个[Cu(en)2]2+配合物阳离子以共价键和弱键相连接形成二维层状结构,相邻层又通过氢键连接成三维超分子网络.研究了化合物1的磁性及光催化降解罗丹明B的活性.     

具有八-环开放骨架结构的Ni3(PO4)2·8H2O的水热合成与表征

由于开放骨架结构的金属酸盐具有潜在的应用前景，因此合成具有开放骨架结构的金属磷酸盐一直是研究的热点［1~3］. 自从第一个具有微孔结构的磷酸铝［4］被报道以来，许多其它具有开放骨架结构的金属磷酸盐被合成出来［5~14］. 然而有关磷酸镍研究的报道很少，仅有几个具有开放骨架结构的磷酸镍［15,16］和一些碱金属的磷酸镍［17~19］(大部分是通过固相法合成的). 本文通过水热法合成了一个新的具有层状结构的磷酸镍［Ni3(PO4)2·8H2O］，并通过X射线单晶衍射测定了其结构，其结构中包含共角的多面体连接成的四元环和八元环.     

Cu-ZSM-5型分子筛的合成与结构表征

近年来，杂原子ZSM-5分子筛合成研究发展极为迅速，许多原子例如B、Ge、Fe等取代铝或佳而进入了分子筛骨架[1-4]．特别是1986年Guth等人间报导在弱酸性体系氟离子存在下合成分子筛，为杂原子沸石分子筛的合成开辟了一条新途径．在碱性体系下，Ione等人[6,7]报导过含铜ZSM-5的合成，但铜是否进入分子筛骨架，尚未给出确切的说明．在微酸性介质中合成Cu－ZSM-5还未见报导．本文在弱酸性介质氟离子存在下，应技合成出氨型Cu-ZSM-5分子筛，并运用XRD、IR、SEM、XPS等方法证明了铜进入了分子筛骨架．1实验1．1试剂白炭．t（SIO。，…     

具有16元环超大孔道磷酸钒化合物的水热合成及表征

分别以正丁胺、正丙胺和哌啶为模板剂,在水热条件下合成了具有超大孔穴的开放骨架磷酸钒化合物VPO-n(n=1,2,3),并对其进行了X射线衍射(XRD)、电感耦合等离子体光谱(ICP)、元素分析、热重分析(TG)、扫描电子显微镜(SEM)、X射线光电子能谱分析(XPS)及单晶结构解析等表征.XRD结果表明,VPO-n(n=1,2,3)与报道的超大孔磷酸钒化合物[HN(CH2CH2)3NH]K1.35[V5O9(PO4)2]·xH2O(简称VPO-DABCO)具有相同结构.对VPO-1的单晶结构解析表明,其结晶属于立方晶系,Im3m空间群,晶胞参数a=b=c=2.6586(3)nm,α=β=γ=90°,V=18.791(4)nm3.VPO-1的无机骨架具有三维交叉的8元环和16元环孔道,以及最大窗口为32元环的超大空穴.详细考察了不同模板剂对合成产物的影响,结果表明,不同的有机胺模板剂可以影响产物的形貌、结构对称性和晶胞参数,并对骨架中孔道的尺寸具有一定的调控作用.     

二维钨-钒簇聚物[Cu（en）2]2·[WⅥ4·5WV2VVVⅣ9·5O44{Cu（en）2（H2O）}2]·3H2O的合成与表征

采用水热法合成了一个钨-钒簇聚物[Cu(en)2]2[WⅥ4.5WV2 VVVⅣ9.5O44{Cu(en)2(H2O)}2]·3H2O(1, en=乙二胺),并通过X射线单晶衍射、元素分析、傅里叶变换红外光谱、X射线粉末衍射、热重分析、价键计算、X射线光电子能谱、电子顺磁共振和磁性分析对其结构和性能进行了表征.结果表明,化合物1是以双支撑的四帽Keggin结构[WⅥ4.5WV2 VⅣ9.5O40(VVO4){Cu(en)2(H2O)}2]4-钨-钒簇合物阴离子为基本结构单元,与4个[ Cu( en)2]2+配合物阳离子以共价键和弱键相连接形成二维层状结构,相邻层又通过氢键连接成三维超分子网络.研究了化合物1的磁性及光催化降解罗丹明B的活性.     

二乙胺导向合成SAPO-34及与其它模板剂的对比

以二乙胺 (DEA) 为模板剂, 合成了 SAPO-34 分子筛, 详细考察了磷酸用量、水用量以及硅源和铝源等因素的影响. 结果表明, 在 0.7 ≤ n(P2O5)/n(Al2O3) ≤ 1.2 及 25 ≤ n(H2O)/n(Al2O3) ≤ 100 范围内, 可以得到纯相 SAPO-34 分子筛, 铝源对所得样品的组成影响较大. 同时, 采用三乙胺 (TEA)、吗啉 (MOR) 以及二乙胺-三乙胺 (DEA-TEA) 混合模板剂合成了 SAPO-34, 通过 X 射线衍射、X 射线荧光分析、扫描电镜、热重和 29Si 固体核磁共振等手段对所得样品进行了表征. 结果显示, 不同模板剂促使硅进入 SAPO-34 骨架的能力顺序为 SAPO-34 (DEA) SAPO-34 (MOR) SAPO-34 (TEA); SAPO-34 骨架中所能容纳的最大 Si(4Al) 含量顺序为 SAPO-34 (DEA) ≈ SAPO-34 (MOR) SAPO-34 (TEA).     

两个Keggin结构锗钨酸盐稀土衍生物的合成、晶体结构及表征

合成了两个基于Dy3＋阳离子和单缺位Keggin阴离子[GeW11O39]8-的锗钨酸盐, [(CH3)4N]1.5H3.5[Dy(H2O)2(GeW11O39)]×1.5H2O (1) 和[Cu(Hen)(en)]2[Cu(H2O)3]0.5{[Cu(H2en)(Hen)]     

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.     

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%).     

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.     

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.     

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.