2-氨基-4-噻唑乙酸乙酯构筑的两个镉配合物的晶体结构及荧光性质

以2-氨基-4-噻唑乙酸乙酯(EATA)和氯化镉水合物为原料,在无水乙醇和乙醇-水混合物两种溶剂中分别合成了配合物[CdCl2(EATA)]n(1)和[CdCl2(EATA)2](2),并利用X-射线单晶衍射、元素分析、红外光谱和荧光光谱对它们进行了表征。配合物1和2都属于单斜晶系,分别为P21/c和Cc空间群,它们的中心金属离子Cd2+均为扭曲的六配位八面体构型。在配合物1中,相邻的2个八面体单元通过2个μ2-Cl-阴离子双桥连形成一维链结构,该一维链进一步通过N-H…Cl分子间氢键形成了三维网络结构,而配合物2则通过大量的N-H…Cl和C-H…Cl分子间氢键等弱作用组装成二维超分子结构。固态荧光光谱分析表明,配合物1和2荧光性质相似,均可归属于由配体到金属间的电荷转移(LMCT)。     

一个基于2-(2-羧基苯基)-1H-咪唑并[4,5-f][1,10]邻菲啰啉配体的二维铅(Ⅱ)配合物的水热合成及晶体结构

在水热条件下,利用邻菲啰啉衍生物2-(2-羧基苯基)-1H-咪唑并[4,5-f][1,10]邻菲啰啉(HL)和Pb(NO₃)₂反应合成了一个配合物[PbL₂]_n (1),并用红外、元素分析和X射线单晶衍射对其结构进行了表征。配合物1属于单斜晶系,空间群为P2₁/c,晶胞参数a=1.345 9(9) nm,b=0.709 4(5) nm,c=3.265 5(2) nm,β=99.6260(10)°,V=3.074 0(4) nm³,Z=4,C₄0H₂₂N₈O₄Pb,M_r=885.85,D_c=1.914 g·cm^-3,μ(Mo Κα)=5.551 mm^-1,F(000)=1 728,GOOF=1.038,R=0.027 0,wR=0.058 1,其中5 067个可观测点(I>2σ(I))。结构分析表明配合物1为二维层状结构。此外,对配合物的热稳定性和发光性质也进行了研究。     

N-皮考林酰肼及其双核钯配合物的晶体结构和荧光性质

合成了配体N-皮考林酰肼(简写为Hphz)及其双核钯配合物[Pd₂(phz)₂Cl₂]. X射线衍射实验结果表明, 配体和配合物晶体均属于单斜晶系, 空间群分别为C 2/c和P 2₁/c, 分子式分别为C₆H₇N₃O和C₁₂H₁₂Cl₂N₆O₂Pd₂. 晶体学参数, Hphz, a＝1.9245(2) nm, b＝0.38927(2) nm, c＝1.8073(2) nm, b＝107.255(2)°, V＝1.2931(2) nm³, Z＝8, D_c＝1.409 Mg/m³, F(000)＝576, μ(Mo Kα)＝0.102 mm^－1, R＝0.0541, wR＝0.1762; [Pd₂(phz)₂Cl₂], a＝1.48274(9) nm, b＝1.44797(9) nm, c＝0.73951(5) nm, b＝92.719(3)°, V＝1.5860(2) nm³, Z＝4, D_c＝2.329 Mg/m³, F(000)＝1072, μ(Mo Kα)＝2.62 mm^－1, R＝0.0262, wR＝0.0555. 在配合物[Pd₂(phz)₂Cl₂]分子内, 两个钯(II)原子, 均呈畸变的N₃Cl平面正方形配位构型, 晶体内通过分子间氢键N—H…Cl 作用形成一维链状结构, 分子间吡啶环存在相互作用. 量子化学从头算方法计算结果表明, 分子内及分子间的金属钯之间也存在相互作用. 红外光谱表明, 配体在形成配合物后, ν(C＝O)和ν(C＝N)红移, ν(C—N)蓝移, 荧光光谱表明, 配合物金属对配体n-π*激发(310 nm)引起的发射峰有较大的影响.     

二维Co(nip)2(py)2(H2O)2配合物的水热合成, 晶体结构和热分解机理研究(nip＝5-硝基间苯二甲酸根, py＝吡啶)

用水热法以5-硝基间苯二甲酸和吡啶为配体合成并培养了Co(nip)₂(py)₂(H₂O)₂的单晶. 对单晶进行了X射线单晶衍射分析、元素分析、傅里叶变换红外光谱分析、差热分析和热重-微商热重分析. 该配合物晶体为单斜晶系, 属于P2(1)/c空间群. 晶胞参数为a＝1.1662(3) nm, b＝1.7734(4) nm, c＝0.6988(2) nm, β＝102.46(4)°, V＝1.4112(6) nm³, Z＝2, D_c＝1.585 Mg/m³, μ(Mo Kα)＝0.688 mm^－1. 所有晶体数据的R因子为: R₁＝0.1064, wR₂＝0.1270; 最终R因子[I＞2σ(I)]为: R₁＝0.0467, wR₂＝0.1008. X射线单晶衍射分析的结果表明, 依靠分子内氢键、分子间氢键、硝基氧之间的弱相互作用以及π-π堆积作用, 配合物分子被连成二维无限平面结构. 根据配合物的热分析结果, 配合物及热分析各阶段残渣的傅里叶变换红外光谱, 我们推测出了配合物的热分解机理.     

4-甲基苯硫乙酸与含氮配体构筑的两个化合物的合成，晶体结构，热稳定性与发光性质的研究

合成了2个配合物[ZnL₂(Him)₂] (1)和[ (Cu₂L₂(phen)₂( μ₂-Cl)₂)·(Cu₂( μ₂-L)₂(phen)₂Cl₂)] (2)(L=4-甲基苯硫乙酸,Him=咪唑,phen=1,10-邻菲咯啉),进行了元素分析、红外、热重等表征,并测定了其晶体结构。配合物1晶体属于单斜晶系,空间群为C2/c。配合物2晶体属于三斜晶系,空间群为P1。配合物1是由N-H…O氢键作用形成的一维带状结构。配合物2的单胞中含有2个分别由氯原子与羧基氧原子桥联的双核独立分子,通过C-H…O,C-H…Cl氢键以及C-H…π作用而构成三维结构。室温固体荧光分析显示配合物1具有较强荧光吸收。     

2-(4-甲基苯甲酰基)苯甲酸构筑的锰(Ⅱ)配合物的晶体结构、电化学、荧光及磁性研究

以2-(4-甲基苯甲酰基)苯甲酸(HL)为配体合成了一个新的锰((Ⅱ)配合物Mn(L)₂(2,2'-bipy)₂。该配合物晶体属单斜晶系,空间群P2₁/c,晶胞参数：a=1.7198(2)nm,b=1.03980(14)nm,c=2.3463(3)nm,β=95.732(3)°,V=4.1748(9)nm₃,D_c=1.346g·cm^-3,Z=4,μ(MoKα)=0.373mm^-1,F(000)=1756,最终偏离因子R₁=0.0423,wR₂=0.0949。标题配合物的中心锰(Ⅱ)离子处于变形的八面体配位环境中。测定了配合物的电化学、荧光和磁性。结果表明：在循环伏安过程中,配合物的电子转移是准可逆的,对应的电极反应是Mn(Ⅲ)/Mn(Ⅱ);配合物在536~556nm之间有一个较强的荧光发射峰;在300~2K,配合物有反铁磁性。     

以5-甲基-3-吡唑甲酸和菲咯啉为配体的锰和镉的配合物的合成、晶体结构和荧光性能

以5-甲基-3-吡唑甲酸和菲咯啉为配体, 合成了一个单核锰(Ⅱ)配合物[Mn(HMPCA)₂(phen)]·2H₂O (1)和一个具有双核结构单元的一维镉(Ⅱ)的配位聚合物[Cd₂(HMPCA)₂(phen)₂(H₂O)₂]·2H₂O (2)(H₂MPCa=5-甲基-3-吡唑甲酸, phen=菲咯啉), 并用元素分析、红外光谱、X-射线单晶衍射结构分析、热重分析等对其进行了表征。配合物1属于三斜晶系, 空间群为P1, 配合物2属于正交晶系, 空间群为Pccn。配合物1中的锰(Ⅱ)离子位于一个畸变的八面体配位环境中, 独立结构单元间通过分子间氢键作用构成一个三维的超分子结构。而在2中, 每个镉(Ⅱ)离子位于一个五角双锥体中, 来自5-甲基-3-吡唑甲酸根的氧原子桥联2个相邻的镉(Ⅱ)离子, 形成一个一维链;这些一维链和水分子通过分子间氢键进一步形成一个三维的超分子结构。考察了配合物1和2的热稳定性和荧光性能。     

以4-(1-咪唑基)苯甲酸和桥联氯构筑的一维梯状结构的镉配位聚合物的晶体结构和荧光性质

水热条件下以CdCl₂和4-(1-咪唑基)苯甲酸(Himbz)为反应物合成出一个新的具有一维梯子型链状结构的配位聚合物 [Cd(imbz)(Cl)(H₂O)]_n(1), 并分别用元素分析, 红外谱图, 差热分析和X-射线单晶衍射表征该结构。晶体结构分析结果表明:4-(1-咪唑基)苯甲酸离子(imbz)将Cd(Ⅱ)离子连接成一维Z字链, 进而通过桥联氯原子被连接成一维梯状链结构, 荧光谱图表明常温固态下配合物1发射蓝色荧光, 荧光寿命为2.21 ns。     

双-单齿芳香酰胺型配体桥联La3＋一维配位聚合物的合成与晶体结构

通过硝酸镧和双-单齿芳香酰胺型配体L {L＝1,4-双[(2'-苄胺甲酰基苯氧基)-甲基]苯}之间的反应得到了配位聚合物{[La(NO₃)₃]₂•L₃}_n, 并用X射线单晶衍射测定了配合物的晶体结构. 配合物为三斜晶系, _P1空间群, 晶胞参数a＝1.1298(2) nm, b＝1.2689(1) nm, c＝2.1030(3) nm, α＝81.189(9)°, β＝80.95(1)°, γ＝65.832(9)°, V＝2.7032(6) nm³, Z＝2, R＝0.0267, wR＝0.0679, La^3＋为9配位, 呈变形的三帽三角棱柱配位构型. 配合物通过配体的桥联作用形成一维环链相间的配位聚合结构, 由于相邻链间不存在氢键和π-π堆积作用, 所以配合物是以单链形式堆积排列.     

以5-甲基-3-吡唑甲酸和菲咯啉为配体的锰和镉的配合物的合成、晶体结构和荧光性能

以5-甲基-3-吡唑甲酸和菲咯啉为配体, 合成了一个单核锰(Ⅱ)配合物[Mn(HMPCA)₂(phen)]·2H₂O (1)和一个具有双核结构单元的一维镉(Ⅱ)的配位聚合物[Cd₂(HMPCA)₂(phen)₂(H₂O)₂]·2H₂O (2)(H₂MPCa=5-甲基-3-吡唑甲酸, phen=菲咯啉), 并用元素分析、红外光谱、X-射线单晶衍射结构分析、热重分析等对其进行了表征。配合物1属于三斜晶系, 空间群为P1, 配合物2属于正交晶系, 空间群为Pccn。配合物1中的锰(Ⅱ)离子位于一个畸变的八面体配位环境中, 独立结构单元间通过分子间氢键作用构成一个三维的超分子结构。而在2中, 每个镉(Ⅱ)离子位于一个五角双锥体中, 来自5-甲基-3-吡唑甲酸根的氧原子桥联2个相邻的镉(Ⅱ)离子, 形成一个一维链;这些一维链和水分子通过分子间氢键进一步形成一个三维的超分子结构。考察了配合物1和2的热稳定性和荧光性能。     

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.     

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.     

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 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.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.