中心金属离子改变诱导MOFs结构和光催化性能的改变

在相同的水热条件下,铜盐、钴盐分别和配体H₂PPCA（H₂PPCA=5-pyrazin-2-yl-1H-pyrazole-3-carboxylic acid）发生反应,生成了2个结构截然不同的金属有机配合物,分别是[Cu（PPCA）（H₂O）]·H₂O（HPU-7）和{[Co（PPCA）（H₂O）]·H₂O}_n（HPU-8）。HPU-7是由CuCl₂·2H₂O与配体在160℃下反应而成的,它呈现出零维的双核铜单元结构。HPU-8是由Co（NO₃）₂·6H₂O与配体在160℃下反应生成的,它呈现出由双核钴单元与配体的骨架相连而成的4,4-连接的二维层结构。中心金属离子的改变导致了不同结构MOF的形成,并且它们的电化学性能研究表明它们是很好的半导体材料,它们都对亚甲基蓝（MB）具有较好的光催化效果。     

三个含4，4''-(吡啶-3，5-二基)二苯甲酸配体的锌(Ⅱ)、镍(Ⅱ)和钴(Ⅱ)配位聚合物的合成、晶体结构及催化性质

采用水热方法,选用4,4''-（吡啶-3,5-二基）二苯甲酸配体（H₂pdba）与菲咯啉（phen）、2,2''-联吡啶（bipy）或2,2''-联咪唑（H₂biim）分别与ZnCl₂、NiCl₂·6H₂O和CoCl₂·6H₂O在160 ℃温度下反应,合成了2个二维层状配位聚合物{[Zn（μ₃-pdba）（phen）]·H₂O}_n （1）和{[Ni（μ₃-pdba）（bipy）]·3H₂O}_n （2）,以及1个具有一维链结构的配位聚合物{[Co（μ₃-pdba）（H₂biim）（H₂O）]·H₂O}_n （3）,并对其结构和催化性质进行了研究。研究表明,在70 ℃条件下配合物1在Henry反应中显示出较好的催化活性。优化了反应参数,对反应底物范围也进行了研究。     

中心金属离子改变诱导MOFs结构和光催化性能的改变（英文）

在相同的水热条件下,铜盐、钴盐分别和配体H_2PPCA(H_2PPCA=5-pyrazin-2-yl-1H-pyrazole-3-carboxylic acid)发生反应,生成了2个结构截然不同的金属有机配合物,分别是[Cu(PPCA)(H_2O)]·H_2O(HPU-7)和{[Co(PPCA)(H_2O)]·H_2O}n(HPU-8)。HPU-7是由CuCl_2·2H_2O与配体在160℃下反应而成的,它呈现出零维的双核铜单元结构。HPU-8是由Co(NO_3)_2·6H_2O与配体在160℃下反应生成的,它呈现出由双核钴单元与配体的骨架相连而成的4,4-连接的二维层结构。中心金属离子的改变导致了不同结构MOF的形成,并且它们的电化学性能研究表明它们是很好的半导体材料,它们都对亚甲基蓝(MB)具有较好的光催化效果。     

基于2,4,4'-联苯三羧酸及菲咯啉的锰(Ⅱ)和镍(Ⅱ)双核配合物的合成、晶体结构及磁性质

通过水热方法,用2,4,4’-联苯三羧酸（H₃btc）和菲咯啉（phen）分别与MnCl₂·4H₂O和NiCl₂·6H₂O反应,合成了2个具有双核结构的配合物[Mn₂ （Hbtc）₂（phen）₄]·5H₂O（1）和[Ni₂（Hbtc）₂（phen）₄]·2H₃btc·4H₂O（2）,并对其结构和磁性质进行了研究。结构分析结果表明2个配合物的晶体都属于三斜晶系,P1空间群。配合物1和2均为双核结构,通过分子间的O-H…O氢键作用,双核的分子被进一步连接成了三维超分子框架。研究表明,双核分子中相邻金属离子间存在反铁磁相互作用。     

1,10-邻菲啰啉和四氟对苯二甲酸构建的两个镍（Ⅱ）的配合物：合成和晶体结构

以醋酸镍、四氟对苯二甲酸（H₂tfbdc）及1,10-邻菲啰啉（phen）为原料在不同的反应条件下合成了2个镍(Ⅱ)的配合物{[Ni（phen）₂（Htfbdc）]2（μ-tfbdc）}·3H₂O（1·3H₂O）和[Ni（phen）₃]2（tfbdc）₂·13H₂O（2·13H₂O）。单晶结构分析显示配合物1·3H₂O中3D超分子结构在C-H…O/F和C-F…π弱相互作用下而成;在配合物2·13H₂O中,水分子和羧酸离子构建的三维氢键框架中含有金属有机离子链客体。此外,在这些3D超分子结构中强氢键作用、C-H…O和C-H…F等弱氢键作用,π…π及C-F/H…π作用均起到了稳定结构的作用。     

基于3，3′，4，4′-四羧基偶氮苯构筑的三个金属配合物的合成、晶体结构及性质

在水热条件下利用H₄ddb配体合成了3个过渡金属配合物[Co₂（ddb）（phen）₂（H₂O）₆]·3H₂O（1）,[Co（ddb）_0.5（bpy）_0.5（H₂O）₃]_n（2）和{[Ag（dpe）]·0.5（H₂ddb）·H₂O}_n（3）（H₄ddb=3,3'',4,4''-四羧基偶氮苯,bpy=4,4''-联吡啶,dpe=1,2-二（4-吡啶基乙烯））,并用元素分析、红外光谱、X射线粉末衍射、X射线单晶衍射对其进行了表征。配合物1为双核结构,基于丰富的氢键作用扩展形成三维超分子网结构。配合物2为基于钴离子通过ddb^4-配体以μ₄：η¹,η¹,η¹,η¹的配位模式连接而成的二维网结构。配合物3是由Ag（Ⅰ）离子与dpe配体形成的直链结构,客体分子H₂ddb^2-通过氢键作用将其扩展为三维超分子结构。此外还研究了配合物1~3的荧光性质和热稳定性。     

基于双吡啶脲类Cd(Ⅱ)、Zn(Ⅱ)、Hg(Ⅱ)配合物的合成及晶体结构

间苯二胺和3-吡啶异氰酸酯在甲苯中加热回流得到双吡啶脲类配体L,然后将配体分别与CdSO₄·8H₂O,ZnI₂,HgI₂,HgCl₂进行配位反应,得到4个配合物{[Cd（L）（SO₄）（H₂O）₃]·H₂O}_n（1）,{[Zn（L）I₂]·2C₂H₅OH}_n（2）,{[Hg（L）I₂]·C₂H₅OH}_n（3）,[Hg（L）Cl₂]·H₂O（4）,并用元素分析、FT-IR、X射线单晶衍射、粉末衍射对其进行了表征。配合物1形成一维螺旋链结构,配合物2和3形成一维“之”字链结构,配合物4形成32元环状结构。     

由联苯三羧酸和含氮配体构筑的钴(Ⅱ)、铅(Ⅱ)和锌(Ⅱ)配合物的合成、晶体结构及荧光性质

采用水热方法，用联苯三羧酸配体（H₃btc）和菲咯啉（phen）或2，2''-联吡啶（2，2''-bipy）分别与CoCl₂·6H₂O、PbCl₂和ZnCl₂反应，合成了一个单核配合物[Co（Hbtc）（phen）₂（H₂O）]·3H₂O（1）以及2个一维链状配位聚合物[Pb（μ₃-Hbtc）（2，2''-bipy）]_n（2）和{[Zn₃（μ₂-btc）₂（μ₂-H₂O）（2，2''-bipy）₃（H₂O）₅]·8H₂O}_n（3），并对其结构和荧光性质进行了研究。结构分析结果表明3个配合物分别属于正交和三斜晶系，Pna2₁和P1空间群。配合物1具有零维单核结构，而且这些单核钴单元通过O-H…O氢键作用进一步形成了三维超分子框架。而配合物2和3具有基于双核单元的一维链结构。研究表明，配合物2和3在室温下能发出蓝色荧光。     

三个3, 5-二(4-吡啶)1, 2, 4-三唑构筑的Co(Ⅱ)配合物的合成, 晶体结构及其热稳定性

采用3,5-二（4-吡啶）1,2,4-三唑（Hbpt）为配体与钴盐反应,在水热法条件下成功合成了3个配合物,分别是：[Co（Hbpt）₂（HCOO）₂（H₂O）₂]_n·4nH₂O（1）,[Co（Hbpt）₂（HCOO）₂（H₂O）₂]_n（2）和[Co（bpt）₂（H₂O）₄]_n·2nH₂O（3）,并通过X-射线单晶衍射和红外对它们进行了表征。配合物1和2均为三斜晶系,P1空间群,配合物3为单斜晶系,P2₁/c空间群。中心金属Co（Ⅱ）都是六配位,每个Co（Ⅱ）分别与2个Hbpt配体桥联而形成零维的结构单元,这些结构单元通过氢键和π-π堆积弱作用进一步连接而形成三维超分子网络结构。此外,还对配合物1和3的热稳定性做了分析。     

基于2-(4'-羧基苯基)咪唑-4,5-二羧酸构筑的三个镉/锌配位聚合物的合成、拓扑结构、荧光光谱及DNA作用

以2-（4''-羧基苯基）咪唑-4,5-二羧酸（H₄CPhIDC,C₁₂H₈N₂O₆）为配体,用溶剂热合成了3种配位聚合物{[Cd₂（CPhIDC）（bimb）]·H₂O}_n（1）、{[Cd₂（CPhIDC）（phen）₂]·3H₂O}_n（2）、{[Zn₂（CPhIDC）（bpp）]·1.5H₂O}_n（3）（bimp=1,4-双咪唑基-丁烷,phen=1,10-菲咯啉,bpp=1,3-双（4-吡啶基）-丙烷）。用元素分析、红外光谱、粉末X射线衍射和单晶X射线衍射对配合物进行了表征和结构分析。结构分析表明,主配体以完全去质子化CPhIDC^4-的形式与中心金属离子形成以μ₄和μ₅为配位模式的二维及三维聚合物。配合物1和3是三维网络结构,同时呈现（3,4,5）-连接的（5·6·7）（4·5²·6·7²）（4·5²·6·7⁴·8²）拓扑结构,两者的不同之处是中心离子和辅助配体。配合物2是二维波纹状渔网结构,呈现4⁴·6²拓扑结构,在其空间填充上又类似于DNA双螺旋链的单螺旋结构。测定了产物的固体荧光光谱;用EtBr荧光探针法研究了配体及配合物与ct-DNA的相互作用。     

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.     

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.     

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.     

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.     

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.     

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.