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)]     

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.     

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.     

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.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.