一个富路易斯碱位配合物的合成、结构及对痕量Ag+的荧光检测

通过溶剂热方法合成了一个由氢键拓展的携带路易斯碱位的三维超分子配位聚合物：{[Cd（HTZ-IP）（HPYTZ）（H₂O）₂]·5H₂O}_n（HTZ-H₂IP=5-（5-四氮唑基）间苯二甲酸;HPYTZ=3,5-（4-吡啶基）-1,2,4-三唑]。X射线单晶衍射结果表明,中心镉离子由含氮杂环羧酸配体和富氮辅助配体连接成"有悬挂手臂"的一维链,而链间则凭借配位水和2个配体的氢键作用拓展成三维超分子化合物。有趣的是配合物存在大量裸露的未配位的N原子,此N原子具有路易斯碱性质,能与路易斯酸性质的Ag⁺有效结合,从而引起配合物的荧光猝灭。该性质能在无色溶液中有效检测10^-4~10^-6 mol·L^-1范围内的痕量Ag⁺离子。     

一个富路易斯碱位配合物的合成、结构及对痕量Ag~+的荧光检测（英文）

通过溶剂热方法合成了一个由氢键拓展的携带路易斯碱位的三维超分子配位聚合物:{[Cd(HTZ-IP)(HPYTZ)(H_2O)_2]·5H_2O}n(HTZ-H_2IP=5-(5-四氮唑基)间苯二甲酸;HPYTZ=3,5-(4-吡啶基)-1,2,4-三唑]。X射线单晶衍射结果表明,中心镉离子由含氮杂环羧酸配体和富氮辅助配体连接成"有悬挂手臂"的一维链,而链间则凭借配位水和2个配体的氢键作用拓展成三维超分子化合物。有趣的是配合物存在大量裸露的未配位的N原子,此N原子具有路易斯碱性质,能与路易斯酸性质的Ag~+有效结合,从而引起配合物的荧光猝灭。该性质能在无色溶液中有效检测10~(-4)~10~(-6) mol·L~(-1)范围内的痕量Ag~+离子。     

一维配位聚合物{[Co(dpa)(H2O)4] ·(dpdo)·(H2O)}n(H2dpa=2, 2′-联苯二酸, dpdo=N, N′-二氧化-4, 4′-联吡啶)的晶体结构和光谱性质

采用水热合成法制备了一个一维配位聚合物{[Co(dpa)(H₂O)₄] ·(dpdo)·(H₂O)}_n (1)(H₂dpa=2, 2′-联苯二酸, dpdo=N, N′-二氧化-4, 4′-联吡啶), 通过红外光谱、紫外光谱、元素分析、XRPD、TGA和X-射线单晶衍射进行了表征。Co(Ⅱ)原子采取了畸变的八面体构型, 6个配位氧原子分别来自于2个dpa^2-配体和4个配位水分子。每一个dpa^2-配体桥联2个Co(Ⅱ)中心, 每一个Co(Ⅱ)原子与2个dpa^2-配体配位进而形成了2₁螺旋链结构。借助溶剂水分子的连接作用, 螺旋链之间通过多种O-H…O氢键作用形成了2D网格, 通过dpdo和2D网格之间多种类型的氢键作用形成了三维超分子结构。测定了室温下聚合物1的固体荧光光谱。     

两个单核镍含氮配体配合物的合成、晶体结构及荧光性质

采用回流法在水溶剂中合成了2个含氮配体单核镍配合物[Ni（phen）₂（H₂O）₂]（1,6-nds）·2H₂O（1）和[Ni（phen）₃]（1,6-nds）·10H₂O（2）（1,6-nds=1,6-萘二磺酸根离子,phen=1,10-邻菲罗啉）。配合物1中,镍离子与2个1,10-邻菲罗啉和2个水分子配位,形成[Ni（phen）₂（H₂O）₂]²⁺阳离子。2个没有配位的水分子通过氢键与[Ni（phen）₂（H₂O）₂]²⁺和1,6-萘二磺酸根离子相互连接形成二维层状结构。配合物2中,镍离子与3个1,10-邻菲罗啉配位,形成[Ni（phen）₃]²⁺阳离子。大量的氢键将自由的水分子和1,6-萘二磺酸根离子连接形成三维网状结构。2个配合物中1,6-萘二磺酸根离子均没有与镍离子配位,只是起到平衡电荷的作用。室温下,配合物显示了较大的荧光发射峰,其最大发射峰分别在443和438nm。     

三个基于1,5-二(2-乙基苯并咪唑基)-戊烷柔性配体的镉配合物

通过设计柔性配体1,5-二（2-乙基苯并咪唑基）戊烷（bep）,在二羧酸辅助配体的调控下成功制备了3个配位聚合物[Cd（bep）（sba）]_n（1）,[Cd（bep）（bda）]_n（2）,and{[Cd₂（bep）（ada）₂]·H₂O}_n（3）（H₂sba=4,4’-磺酰基二苯甲酸,H₂bda=4,4’-联苯二甲酸,H₂ada=1,3-金刚烷二乙酸）。配合物均呈现二维层状结构。配合物1由交替的Cd（Ⅱ）/bep/sba^2-螺旋链构成。配合物2由Cd/bda^2-单元构成二维结构,bep作为单齿配体与Cd（Ⅱ）配位。配合物3的二维层通过Cd/ada^2-/H₂O氢键螺旋链拓展成三维超分子。此外,对配合物1~3的粉末X射线衍射、热稳定性以及荧光性质进行了研究。     

基于双吡啶酰胺配体的一维汞(Ⅱ)配位聚合物的合成、晶体结构、荧光及蒸气吸附性质

分别将2个双吡啶酰胺配体（L¹和L²）与碘化汞进行配位反应,设计并合成了2个配位聚合物{[Hg₂（L¹）（μ₂-I）₂I₂]·2DMF·H₂O}_n（1）和{[Hg（L²）I₂]·H₂O}_n （2）。X射线单晶分析表明,这2种配合物均呈现为一维“之”字形链状结构,但通过调整配体中的3-和4-吡啶氮原子位点表现出不同的配位模式。2个配合物中Hg（Ⅱ）中心均为四配位的扭曲四面体构型。在配合物1中,Hg（Ⅱ）中心与1个3-吡啶氮原子和3个碘离子配位,配体L¹与碘化汞的物质的量之比为1∶2。在配合物2中,Hg（Ⅱ）中心与2个4-吡啶氮原子和2个碘离子配位,配体L²与碘化汞的物质的量之比为1∶1。此外,考察了2个配合物的热稳定性、固态荧光及蒸气吸附性质。     

基于3,5-二(3-吡啶)-4-氨基-1,2,4-三唑配体的Co(Ⅱ)和Cu(Ⅱ)配合物的合成与晶体结构

利用3,5-二（3-吡啶）-4-氨基-1,2,4-三唑（L）配体与Co（Ⅱ）/Cu（Ⅱ）盐室温下反应得到了一维的配位聚合物{[CoL（H₂O）₄]SO₄·H₂O}_n（1）和单核配合物[Cu（hfac）₂L₂]（2,hfac=hexafluoroacetylacetonate）。通过红外、元素分析及X射线单晶衍射等检测手段对所合成的配合物进行了表征。结构研究表明,配合物1中,配体L呈顺式构型,采取双齿配位方式桥联Co（Ⅱ）离子形成一维正弦链状结构,一维链通过多种氢键相互作用连接进一步形成三维网状结构;溶剂水分子和硫酸根阴离子通过氢键连接在框架上。配合物2中,配体L则采取单齿配位方式,与Cu（Ⅱ）离子形成离散型的单核结构,通过多重氢键作用进而连接成三维网状结构。     

基于3,5-二(3-吡啶)-4-氨基-1,2,4-三唑配体的Co(Ⅱ)和Cu(Ⅱ)配合物的合成与晶体结构

利用3,5-二（3-吡啶）-4-氨基-1,2,4-三唑（L）配体与Co（Ⅱ）/Cu（Ⅱ）盐室温下反应得到了一维的配位聚合物{[CoL（H₂O）₄]SO₄·H₂O}_n（1）和单核配合物[Cu（hfac）₂L₂]（2,hfac=hexafluoroacetylacetonate）。通过红外、元素分析及X射线单晶衍射等检测手段对所合成的配合物进行了表征。结构研究表明,配合物1中,配体L呈顺式构型,采取双齿配位方式桥联Co（Ⅱ）离子形成一维正弦链状结构,一维链通过多种氢键相互作用连接进一步形成三维网状结构;溶剂水分子和硫酸根阴离子通过氢键连接在框架上。配合物2中,配体L则采取单齿配位方式,与Cu（Ⅱ）离子形成离散型的单核结构,通过多重氢键作用进而连接成三维网状结构。     

一系列萘羧酸膦酸镧系配合物的合成、结构和荧光性质

在溶剂热条件下，5-羧酸-1-萘膦酸（5-pncH₃）和稀土硝酸盐反应合成得到3例萘羧酸膦酸镧系配合物：[Pr （5-pnc）（H₂O）]·2H₂O （1）、[Sm （5-pnc）（H₂O）]·H₂O （2）和[Eu （5-pnc）（H₂O）]·H₂O （3）。采用单晶X射线衍射、粉末X射线衍射、元素分析、红外光谱、热重分析和荧光光谱对配合物进行了表征。晶体结构表明，每个七配位的镧系离子由来自5个膦酸盐配体的6个O原子和来自1个配位水分子的一个O原子配位。[LnO₇]通过O—C—O、O—P—O或—O—单元连接成一维双金属链结构，一维双金属链再进一步由萘羧酸膦酸配体（5-pnc^3-）连接成三维开放骨架结构。荧光性质研究表明，配合物3在330 nm的激发光下，发射Eu的红色特征荧光，而配合物1和2在蓝光区显示出非常宽的配体中心发射带。     

由异烟酰腙构建的多孔状Zn（Ⅱ）配位聚合物{[Zn（L）2（H2O）2]·4H2O}n 的合成及其晶体结构

以邻甲酰基苯磺酸钠和异烟肼为原料在乙醇/水溶液中制备了一种酰腙类Schiff碱配体（NaL）,采用常规溶液挥发法合成了由该配体构筑的Zn（(Ⅱ)配位聚合物{[Zn（L）₂（H₂O）₂]·4H₂O}_n。利用元素分析、IR、TGA和X-射线单晶衍射分析对配合物进行了表征。配合物晶体属三斜晶系,P1空间群,晶胞参数a=0.78698（4）nm,b=0.86926（5）nm,c=1.18044（7）nm,α=103.353（5）°,β=100.965（4）°,γ=93.123（4）°,Z=1,V=0.76724（7）nm³,D_c=1.697g·cm^-3。每个Zn(Ⅱ)离子被2个配体L^-阴离子双重桥联形成二核环状结构单元,并通过共用锌离子形成一维链配位聚合物,链与链之间通过氢键扩展为具有一维开放孔道的三维超分子网络结构。     

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.     

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.     

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.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

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.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

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.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

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.