基于[P_2W_(15)O_(56)]~(12-)构筑块的四核铜夹心型化合物的合成、结构表征及其热稳定性

以三缺位型Dawson结构的钨磷酸盐前驱体Na12[α-P2W15O56]·24H2O与CuCl2·6H2O和Na3PO4为原料、水为溶剂,经溶液合成法合成了四核夹心型多金属氧酸盐化合物Na3H13[Cu4(H2O)2(P2W15O56)2]·72H2O(1);利用X射线单晶衍射仪、红外光谱仪、紫外光谱仪、X射线粉末衍射仪等分析了合成产物的结构,采用变温红外光谱测定了其热性质.结果表明,该化合物为三斜晶系,P-1空间群;其晶胞参数为:a=1.318 1(2)nm,b=1.345 1(2)nm,c=2.497 3(4)nm,α=78.149(3)°,β=88.242(3)°,γ=62.087(2)°.该化合物的骨架结构由两个三缺位的Dawson结构单元{P2W15O56}通过一个{Cu4O16}簇连接而成;其在350℃以下表现出一定的热稳定性.     

[Cu(en)_2]~(2+)修饰的二维仲钨酸化合物:[{Na_3(H_2O)_(10)}_2H_2{Cu(en)_2(H_2W_(12)O_(42))}]·16H_2O(英文)

利用水热合成法制备了一种基于[Cu(en)2]2+修饰的仲钨酸化合物:[{Na3(H2O)10}2H2{Cu(en)2(H2W12O42)}].16H2O(en=乙二胺)(1),借助元素分析、X射线单晶衍射分析I、R、UV、热分析和X射线光电子能谱对这种化合物进行了结构和性质研究.化合物(1)属于三斜晶系,P-1空间群.晶胞参数为:a=1.183 2(5)nm,b=1.296 0(6)nm,c=1.416 9(6)nm,α=63.348 0(10)°,β=82.844 0(10)°,γ=68.907 0(10)°,V=1.810 0(14)nm3,Z=1,R1[I2σ(I)]=0.024 7,wR2[I2σ(I)]=0.058 2.化合物(1)通过仲钨酸阴离子,铜离子和[Na3(H2O)10]3+三核簇形成了新型的二维层状结构.     

含新颖一维金属氧簇阳离子的聚金属氧簇化合物[{M(2,2''-bipy)}5O14]4-[2,2''-H2bipy]2(As2W18O62)2·8H2O(M=Mo,W)的合成、晶体结构与表征

以Na2WO4·2H2O,Na2MoO4·2H2O,Na2HAsO4·7H2O和2,2'-bipyridine为原料,在水热条件下制得了含一维阳离子的聚金属氧簇化合物:[{M(2,2'-bipy)}5O14]4[2,2'-H2bipy]2(As2W18O62)2·8H2O(M=Mo/W;2,2'-bipy=2,2'-bipyridyl),并用元素分析,IR,TG和单晶X-ray衍射等手段进行了表征.标题化合物属于单斜晶系,C2/c空间群,a=4.1721(5)nm,b=2.4629(5)nm,c=1.7541(5)nm,β=91.119(3)°,V=18.021(5)nm3,Z=2,R1=0.0629,wR2=0.1605[I>2σ(I)].标题化合物的阳离子链由五元金属氧簇构筑块[{M(2,2'-bipy)}5O14]2 通过氧原子桥联而成,构筑块[{M(2,2'-bipy)}5O14]2 中的五个金属原子呈畸变的"A"字型排布,阳离子展现出新颖的一维锯齿链状结构.     

Anderson-B-型多金属氧酸盐[Co(2,2''-bipy)3]H-[Al(OH)6(Mo6O18)]·5H2O的合成及晶体结构

以AlCl3·6H2O、Na2MoO4·2H2O、CoCl2·6H2O和2,2'-联吡啶为主要原料合成了Anderson-B-型多金属氧酸盐[Co(2,2'-bipy)3]H[Al(OH)6(Mo6O18)]·5H2O,进行了红外光谱、紫外光谱、差热分析和单晶结构测定.晶体学测定结果表明,化合物属于三斜晶系,Pi空间群,晶胞参数:a=1.216 0(2),b=1.221 5(2),c=1.780 0(4)nm,α=86.83(3)°,β=88.76(3)°,γ=89.82(3)°,V=2.639 4(9)nm3,Z=2,R1=0.079 4,wR2=0.176 6.化合物结构分析表明,在晶体学上,标题化合物分子是由1个[Co(2,2'-bipy)3]2+配阳离子,1个H+离子,2个1/2[Al(OH)6(Mo6O18)]3-多阴离子和5个结晶水分子组成.多阴离子[Al(OH)6(Mo6-O18)]3-借助水分子和金属配离子通过超分子作用形成二维网状结构,网状结构之间又借助超分子作用形成三维无限伸展结构.差热分析表明,标题化合物的失重过程分为2步,多阴离子骨架破坏温度为547.5℃.     

新型无机-有机杂化化合物(Hmorph)_4[SiMo_(12)O_(40)]·2H_2O合成与性质研究

合成了1种无机-有机杂化钼酸盐化合物(Hmorph)4[SiMo12O40]·2H2O(Hmorph=morpholine,吗啉).用元素分析、X射线单晶衍射、红外光谱和热重对晶体的结构进行了表征.该晶体属于三斜晶系,P-1空间群,晶胞参数a=1.214 71(13)nm,b=1.399 0(3)nm,c=1.735 1(2)nm,α=79.892(13)°,β=82.719(9)°,γ=71.812(14)°,V=2.749 7(7)nm3,Z=2.在该化合物晶体结构中包含质子化的吗啉分子、带负电荷的Keggin结构多阴离子簇以及水分子,在分子中通过静电引力及氢键作用交替排列.紫外光谱和电化学实验证明,标题化合物(Hmorph)4[SiMo12O40]·2H2O在水溶液中对ClO3-具有良好的电催化性质.     

一种有机-无机复合Dawson类型磷钨酸盐[H_24,4′-bpy]_5[H_2bpb]_(0.5)H[α-P_2W_(18)O_(62)]_2·4H_2O（英文）

利用水热技术合成了一种新的有机-无机复合的磷钨酸盐[H24,4′-bpy]5[H2bpb]0.5H[α-P2W18O62]2·4H2O(1)(4,4′-bpy=4,4′-bipyridine,bpb=1,4-bis(pyrid-4-yl)benzene),并通过红外光谱和X射线单晶衍射等技术对其结构进行了表征.化合物1属于三斜晶系,P-1空间群,其晶体学数据为a=1.461 83(10)nm,b=2.161 31(14)nm,c=2.632 87(19)nm,α=81.686 0(10)°,β=80.124 0(10)°,γ=84.893 0(10)°,V=8.091 5(10)nm3,Z=2,GOOF=1.007,R1=0.058 6,wR2=0.121 4.化合物1分子结构包含5个双质子化的4,4′-联吡啶阳离子、0.5个双质子化的1,4-二(4-吡啶基)苯阳离子、1个H+离子、2个饱和Dawson结构多阴离子[α-P2W18O62]6-和4个结晶水分子.此外,我们还研究了它的电化学性质.     

N-苯甲酰基水杨酰肼为配体的三核镍(Ⅱ)配合物的合成与结构

N-苯甲酰基水杨酰肼配体(简写为H3Bzshz)与Ni(OAc)2·4H2O在不同的溶剂中反应得到2个三核镍配合物[Ni3(Bzshz)2(C5H5N)6](C5H5N)·CH3OH·2H2O(1)和[Ni3(Bzshz)2(OH)2(C2H6O)2]·2(C3H7NO)·0.5C2H6O(2).X射线衍射实验结果表明:化合物1属单斜晶系,空间群为P2(1)/n,晶胞参数a=2.198 9(2) nm,b=1.336 9(1) nm,c=2.503 4 nm,β=107.886(1)°,V=7.004(1) nm3,Z=4,R1=0.081 0,wR=0.215 4.3个Ni原子依次以八面体/八面体/平面正方形配位,其中Ni(1)…Ni(2)…Ni(3)原子间角是169.84(3)°,形成准直线形三核镍配合物;化合物2属三斜晶系,空间群为P-1,晶胞参数a=1.138 9(2) nm,b=1.368 2(2) nm,c=1.563 3(2) nm,α=67.190(2)°,β=83.953(2)°,γ=83.618(2)°,V=2.226 3(4) nm3,Z=2,R1=0.065 2,wR=0.188 0,而3个中心原子Ni(1)…Ni(2)…Ni(3)原子间角是180°,且依次以平面正方形/八面体/平面正方形相交替方式配位,具有中心对称的直线形结构.     

以钒为杂原子的Keggin结构阴离子有机-无机复合物[Co(phen)3]4[VW12O40](OH)5的合成及晶体结构

以NH4VO3、Na2WO4.2H2O、CoCl2.2H2O、C12H8N2.H2O(邻菲啰啉,phen)为原料,用水热合成法制得了分子式为[Co(phen)3]4[VW12O40](OH)5的有机-无机复合物,并对其进行了元素分析、IR及X射线单晶衍射等表征。结构测定表明,该化合物属于三斜晶系,P墿空间群,晶胞参数:a=1.638 9(3)nm,b=1.774 4(4)nm,c=18.275(4)nm,α=61.04(3)°,β=78.49(3)°,γ=64.64(3)°,V=4.201 8(15)nm3,Z=1,R1=0.083 6,wR2=0.222 8。标题化合物分子是由4个手性的[Co(phen)3]2 配阳离子,1个[VW12O40]3-阴离子及5个游离的OH-组成。4个[Co(phen)3]2 配阳离子通过静电引力呈平行四边形分布在[VW12O40]3-阴离子的周围,[VW12O40]3-阴离子位于平行四边形的中心。化合物分子间通过π-π堆积等作用形成三维网状结构。     

由柔性双吡唑配体构筑的两个多酸基化合物

利用水热合成方法合成了两个新的Keggin基有机-无机杂化化合物:[Cu(H2bdpm)2(H2PMo12O40)]·3H2O(1)和[Ag(H2bdpm)2Na2(H2O)3(HSi W12O40)]·3H2O(2),并通过元素分析、红外光谱和X-射线单晶衍射方法确定了两个化合物的晶体结构。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a=12.827(7)nm,b=12.888(7)nm,c=19.345(11)nm,α=80.414(10)°,β=89.761(10)°,γ=78.477(10)°,V=3088.6(3)nm3。化合物2属于三斜晶系,P-1空间群,晶胞参数a=12.958(5)nm,b=12.965(5)nm,c=19.522(7)nm,α=80.731(6)°,β=89.284(6)°,γ=78.047(7)°,V=3166(2)nm3。化合物1展示了一个由Keggin型多酸和[Cu(H2bdpm)2]+亚单元相互连接而形成的一维链结构;化合物2中包含一个Si W12-Na构筑的无机链,而[Ag(H2bdpm)]+亚单元上下交替共价键连到该无机链上,进一步稳固了一维链的结构。标题化合物的光催化降解亚甲基蓝实验表明,目标化合物具有光催化性能,可作为潜在的无机-有机杂化功能材料。     

[Ln2（HINC）4]6+（Ln=Ce,Eu）二聚体修饰的两个Dawson型超分子化合物的合成与晶体结构

利用水热合成方法合成了2个新的双核稀土-异烟酸配合物修饰的Dawson型有机-无机杂化化合物[Ln2(HINC)4(H2O)8(P2W18O62)]·nH2O(Ln=Ce(1),Eu(2);n=16(1),9(2);INC=4-吡啶羧酸/异烟酸).化合物1与2同构,并通过红外光谱、元素分析和X-射线单晶衍射方法确定了该化合物的晶体结构.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a=1.323 6(3)nm,b=1.865 0(4)nm,c=2.287 2(5)nm,α=67.26(3)°,β=78.01(3)°,γ=70.34(3)°,V=4.883 8(17)nm3,Z=2.化合物2也属于三斜晶系,P-1空间群,晶胞参数a=1.320 1(2)nm,b=1.856 9(3)nm,c=2.285 6(4)nm,α=67.378(2)°,β=77.745(3)°,γ=70.039(3)°,V=4.839 8(13)nm3,Z=2.     

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.     

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.     

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%).     

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.