多金属氧酸盐修饰的过渡金属配合物的催化效果和电化学行为

基于水热技术,合成了多金属氧酸盐修饰的2种新的过渡金属配合物[Cu（dmbipy）²（SiW¹²O⁴⁰）][Cu（dmbipy）（H₂O）₃]·3H₂O（1）和{（Hdmphen）²[Ag₂（dmphen）²（SiW¹²O⁴⁰）]}_n（2）（dmbipy=4,4’-二甲基-2,2’-联吡啶,dmphen=2,9-二甲基-1,10-菲咯啉）。配合物1的最小不对称单元包含2种不同的Cu（Ⅱ）单元,其中Cu（Ⅱ）离子都采用了五配位的模式,并且水分子也参与了配位。氢键将不同的Cu（Ⅱ）单元连接形成了一维链,并延伸至二维层。在配合物2中,多金属氧酸盐连接Ag（Ⅱ）离子形成一维链。氢键和π…π堆积作用将一维链拓展成了二维层。     

多金属氧酸盐修饰的过渡金属配合物的催化效果和电化学行为（英文）

基于水热技术,合成了多金属氧酸盐修饰的2种新的过渡金属配合物[Cu(dmbipy)2(Si W12O40)][Cu(dmbipy)(H2O)3]·3H2O(1)和{(Hdmphen)2[Ag2(dmphen)2(Si W12O40)]}n(2)(dmbipy=4,4′-二甲基-2,2′-联吡啶,dmphen=2,9-二甲基-1,10-菲咯啉)。配合物1的最小不对称单元包含2种不同的Cu(Ⅱ)单元,其中Cu(Ⅱ)离子都采用了五配位的模式,并且水分子也参与了配位。氢键将不同的Cu(Ⅱ)单元连接形成了一维链,并延伸至二维层。在配合物2中,多金属氧酸盐连接Ag(Ⅱ)离子形成一维链。氢键和π…π堆积作用将一维链拓展成了二维层。     

刚性不对称三氮唑衍生物的Cd(Ⅱ)配合物的制备、晶体结构及其荧光性质

用水热法合成了基于刚性不对称三氮唑衍生物配体H₂ptp （H₂ptp=4-（5-（1H-pyrazol-4-yl）-4H-1,2,4-triazol-3-yl）pyridine）的2个Cd（Ⅱ）配合物 {[Cd₂（Hptp）₂（OAc）₂]·7H₂O}_n （1）和{[Cd（Hptp）Cl（H₂O）]·H₂O}_n （2）,并通过元素分析、差热分析、粉末X射线衍射和单晶X射线衍射进行表征。配合物1具有一个梯状的一维结构,在π…π堆积作用下这些一维梯链形成了超分子二维平面。在氢键的连接作用下,客体水分子形成了独特的以双五元水簇为结构单元的水链,这些水链填充在相邻的二维平面之间并通过氢键把二维平面连接成了三维超分子网络。配合物2具有一个新型的二维双层结构,分子间氢键把这些二维平面连成了三维结构。另外,测试了2个配合物的荧光性质。     

基于配位键和次级作用力协同效应构建的两个Co (Ⅱ)/Cd (Ⅱ)配位超分子网络的结构及荧光性质

以3-羧基-1-（4-羧基苄基）吡啶溴酸盐（（H₂L） Br）分别与Co （Ⅱ）和Cd （Ⅱ）金属盐反应,制备了2个配合物[Co （L）₂（H₂O）₄]·2H₂O （1）和[Cd （L）2（H₂O）]·3H₂O （2）。晶体结构分析揭示配合物1是一个中性的单核配合物,其拥有丰富的并可作为超分子合成子的氢键和π-π作用力组分。对于1,单核的[Co （L）₂（H₂O）₄]实体首先通过氢键形成具有孔道结构的二维层,该二维层进一步通过π-π堆积作用形成三维的多孔配位超分子。配合物2具有一维的“之”字形链状结构,该链通过悬挂的L配体之间的π-π作用力形成一维梯形结构。该一维梯形链进一步通过梯形边之间存在的2种π-π堆积作用形成波浪状的二维层。二维层进一步通过8种类型的O—H…O氢键连接形成三维的超分子结构。根据拓扑的观点,配合物2中的一维链采取胶合板排列。此外,配合物2显示了强的紫外荧光发射,平均寿命为2.54 ns。     

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。     

由大茴香酸与含氮杂环配体构筑的锌、铜配合物的水热合成、晶体结构与荧光性质

通过水热法,以大茴香酸（Hmba=methoxybenzoic acid）、2,2’-联吡啶（bipy）为配体,合成了2个配合物：[Zn（mba）（bipy）（HCOO）]_n（1）和[Cu（mba）（bipy）₂]·2Hmba（2）,对其进行了红外光谱、热重分析、单晶X射线衍射和荧光光谱等分析。配合物1属单斜晶系,空间群为P2/c,Zn（Ⅱ）离子处在五配位的变形三角双锥环境中。每个HCOO-桥联2个相邻Zn（Ⅱ）离子,形成一维链,然后通过氢键作用和芳环间的π-π堆积延伸一维链为三维网络超分子结构。配合物2属三斜晶系,空间群为P1,Cu（Ⅱ）离子与配位原子构成五配位的变形三角双锥结构。其配合物单元通过芳环间的π-π堆积作用连接为一维超分子链,一维链通过氢键、芳环间的π-π堆积和C-H…π相互作用拓展为三维超分子结构。荧光光谱研究表明,配合物1在327 nm（λ_max）处具有强的荧光发射。     

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。     

1,3-金刚烷二乙酸配体构筑的两个镉配合物的合成、表征及晶体结构

合成了2个一维Cd(Ⅱ)配合物[CdL(2,2′-bipy)]_n·nH₂O (1)和[CdL(2,2′-bipy)(H₂O)]_n·4nH₂O (2)(H₂L为1,3金刚烷二乙酸),并经X-射线单晶衍射方法测定了它们的晶体结构。在配合物1中,中心金属Cd(Ⅱ)为七配位的单帽三棱柱结构,而在配合物2中,Cd(Ⅱ)为七配位的五角双锥结构。1,3金刚烷二乙酸根作为桥联配体连接中心金属Cd(Ⅱ)离子形成一维链,同时通过氢键和π-π堆积作用形成三维超分子结构。研究了配合物1的荧光光谱。     

基于单-和双-三唑衍生物的三个Cu(II)和Cu(I)多金属氧簇基配合物的水热合成及光催化性能

在水热条件下，利用多齿的单-和双-三唑衍生物，制备了3种基于多金属氧簇基（POM）的Cu（Ⅱ）和Cu（I）杂化材料，即{[Cu（L₁）₂（Mo₄O₁₃）]·2H₂O}_n（1），{[Cu_1.5（L₂）（HL₂）（H₂O）（Mo₄O₁₃）]·2H₂O}_n（2），{[Cu₂（L₃）_1.5（Mo₄O₁₃）]·H₂O}_n（3）（L₁=4-pyridine-2-1，2，4-triazole，HL₂=3-（4H-1，2，4-triazol-4-yl）benzoic acid，L₃=trans-4，4''-azo-1，2，4-triazole）。通过单晶X射线衍射、傅里叶变换红外光谱和粉末X射线衍射分析确定了它们的结构。在1中，Mo₄O₁₃^2-阴离子和Cu（Ⅱ）中心通过双齿L₁相互连接，最终形成了二维（2D）POMs基的Cu（Ⅱ）杂化金属-有机骨架。在2中，Mo₄O₁₃^2-阴离子和Cu（Ⅱ）中心通过桥接水原子（O18），双齿HL₂和三齿L₂^-相互连接，最终形成了三维（3D）POMs基的Cu（Ⅱ）微孔金属-有机骨架。在3中，L₃配体桥接相邻的Cu（I）中心和Mo₄O₁₃^2-阴离子，最终形成独特的双重穿插结构的3DPOMs基的Cu（I）杂化配位框架。光催化实验研究表明，样品1~3对于不同有机染料罗丹明B（RhB）、亚甲基蓝（MB）和甲基橙（MO）都具有很好的光催化降解能力。     

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。     

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%.     

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 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.     

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.