多羧酸根铕二元配合物的合成及光谱分析

分别以1,3,5-苯三甲酸(H₃BTC)、苯六甲酸(H₆MTA)和1,2,3,4,5,6-环己六甲酸(H₆CCA)为配体合成了Eu(III)的二元发光配合物Eu(BTC)·2H₂O, Eu₂(MTA)·4H₂O 和Eu₂(CCA)·4H₂O. 通过元素分析、红外光谱和等离子体原子发射光谱对其化学组成进行了结构表征, 表征结果与理论吻合良好. 利用荧光分度计, 研究了所制备配合物室温条件下的荧光性能(荧光激发光谱、发射光谱、荧光寿命和量子效率), 结果表明: 该三种配合物在紫外光照射下, 均发射Eu(III)离子的特征红光, 其中Eu₂(MTA)·4H₂O(量子效率＝10.25%, 荧光寿命＝0.36 ms)的荧光性能最好, 这说明配体H₆MTA 的能级与Eu³⁺离子能级匹配程度很好. 另外, 通过热分析对配合物的热稳定性进行了分析, 结果表明: 该三种配合物均具有良好的热稳定性, 主要分解温度远高于其他β-二酮配合物.     

姜黄素稀土大环配合物的光致变色性能研究

通过模板反应, 以姜黄素和二乙烯三胺为配体合成了一系列的双姜黄素缩双二乙烯三胺(L)稀土大环配合物. 并用核磁共振氢谱、红外光谱、热重-差热、摩尔电导和元素分析进行了表征. 确定配合物的组成为: [LnL(NO₃)₃]•4H₂O (Ln＝La, Ce, Pr, Nd, Sm, Eu, Dy). 研究了配合物在室温下的荧光性质, 结果表明配合物表现出相应姜黄素的特征发射. 实验表明配合物具有良好的光致变色性能, 并用稳态和时间相关荧光光谱对配合物溶液的光致变色行为进行了研究. 在光照下, 配合物分子中的配体结构由烯胺式变为亚胺式, 溶剂对配合物光致变色性质的影响也进行了探讨.     

桑色素金属(Ⅱ)固体配合物的抗氧性研究（英文）

本文报道了五种金属(Ⅱ)桑色素固体配合物的合成.通过元素分析、溶解尔电导、红外光谱、热重差热、核磁共振氢谱和荧光分析测定了配合物的组成和性质，结果表明配合物组成为ML2*nH2O[M=Mn(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、Cu（Ⅱ)、Zn(Ⅱ)；L=Morin(失去2`-OH中质子）；n=2或3].并对配体、配合物进行了脂质过氧化物生成的抑制和清除O-2。自由基的对比研究。     

PMBP缩氨基酚配合物的合成、结构和抑菌活性

利用PMBP缩邻、间和对氨基酚配体(C23H19N3O2), 合成了它们的Cu (II), Co (II), Fe (II) 和Zn (II) 配合物. IR, UV, 1 H NMR和EI-MS测定结果表明PMBP缩邻氨基酚配体以负二价三齿形式与金属形成1:1的配合物, 而PMBP缩间氨基酚和PMBP缩对氨基酚配体均以二齿形式与金属形成2:1的配合物。抑菌活性测定结果表明配合物对金黄色葡萄球菌和大肠杆菌的抑制活性大于配体, 其中PMBP缩邻氨基酚合钴(II) 配合物在2.5 g/L浓度下对大肠杆菌的抑菌环直径达到19 mm, 为研究配合物的生物活性提供了科学依据。     

新型水溶性手性Salen配合物的合成及性质研究

合成并表征了新型水溶性手性Salen 配体(R,R)-N,N’-二{4-[2-(三甲胺基)乙氧基]水杨醛}-1,2-环己二胺二高氯酸盐(L)及金属配合物ML [M＝Zn(II), Cu(II), Ni(II), Co(II), Fe(III), Mn(III)]. 讨论了手性配体L及配合物ZnL的电子光谱和圆二色光谱性质, 用UV-Vis光谱滴定和CD光谱滴定法研究了ZnL对手性氨基酸对映异构体的分子识别. 测定了主体ZnL与客体氨基酸轴向配位反应的配位数(n)、缔合常数(K)及热力学函数 测得缔合常数的大小顺序为KPhe＞KVal＞KThr. 研究发现反应是放热、熵减小的过程. 用凝胶电泳的方法初步研究了此类手性金属配合物在H2O2存在下对DNA的裂解作用.     

含四硫富瓦烯Schiff碱配体和配合物二阶非线性光学性质的密度泛函理论研究

采用密度泛函理论(DFT)B3LYP(UB3LYP)/6-31g*方法对含四硫富瓦烯Schiff碱配体和它的Fe(III/II),Co(II),Ni(III/II),Cu(II)配合物的极化率和二阶非线性光学(NLO)性质进行了研究,并对其中闭壳层分子采用含时密度泛函理论(TD-DFT)方法计算了电子光谱.结果表明:含四硫富瓦烯Schiff碱配体本身具有较大的二阶NLO系数,二价金属配合物二阶NLO系数与配体接近,三价金属配合物二阶NLO系数约为配体的30倍.金属配合物不同自旋多重度时其二阶NLO系数相差不大.结合配体和配合物的前线分子轨道分析可知,配体和二价金属配合物的二阶NLO系数主要是配体内的电荷转移(ILCT)的贡献,三价金属配合物既有ILCT又有金属与配体间电荷转移(MLCT),同时前线分子轨道能级差显著减小,因此它们的二阶NLO系数显著增大.     

一种新颖酰基硫脲金属簇合物的合成与晶体结构

报道了一种新型酰基硫脲金属簇合物[Cu₆(HL)₆] (HL＝N-乙氧羰基-N'-4-氟苯基硫脲)的合成和晶体结构. 对化合物用元素分析、红外光谱、核磁共振谱、差热-热重分析确定了配合物的组成, 并经X射线单晶衍射法确定了其单晶结构. 晶体结构表明, 该化合物属于三斜晶系, 空间群, a＝1.2508(11) nm, b＝1.3011(11) nm, c＝1.4686(12) nm, a＝102.401(14)°, β＝97.859(2)°, γ＝114.700(13)°, V＝2.051(3) nm³, Z＝1, D_c＝1.687 Mg/m³. 标题化合物是由六个铜离子和六个硫脲配体组成的笼状金属簇合物, 每一个硫脲配体上与乙氧酰基相连的氮原子与铜进行配位, 并且配体上硫羰基上的硫原子与铜也发生配位作用, 使它们互相连接形成畸变的多面体结构.     

桑色素金属(Ⅱ)固体配合物的抗氧性研究

本文报道了五种金属(Ⅱ)桑色素固体配合物的合成。通过元素分析、溶解度、摩尔电导、红外光谱、热重差热、核磁共振氢谱和荧光分析测定了配合物的组成和性质,结果表明配合物组成为ML₂·nH₂O[M=Mn(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、Cu(Ⅱ)、Zn(Ⅱ);L=Morin(失去2′-OH中质子);n=2或3]。并对配体、配合物进行了脂质过氧化物生成的抑制和清除O₂^-·自由基的对比研究。     

2,2'-联苯二羧酸配合物的合成、表征及性质

基于配体2,2'-联苯二羧酸(H₂oba),以水热法合成出双核簇状配位化合物[Zn₂(oba)₂·2H₂O]_n,并通过单晶X衍射分析、元素分析、荧光分析和热重分析对其进行结构表征。 结果表明,配合物属于单斜晶系,P2₁/c空间群,配合物的晶胞单元中包含2个独立的锌离子、2个H₂oba配体和两个水分子。 在配位键的作用下,配合物具有无限循环的一维链状结构,再通过氢键的作用最终形成二维空间结构。 此外,还对该化合物做了抗氧化活性(SOD)的研究,抗氧化活性研究表明配合物有较好的抗氧化活性,其IC₅₀(半数抑制浓度)值为25.0 mg/L,是一种良好的超氧化物歧化酶(SOD)模拟物。     

水杨醛缩L-异亮氨基酸Schiff碱过渡金属Cu(Ⅱ),Zn(Ⅱ),Ni(Ⅱ)配合物的电化学合成及表征

采用Cu, Zn, Ni为“牺牲”阳极, 在无隔膜电解槽和含配体水杨醛缩L-异亮氨基酸Schiff碱的乙腈溶液中电解合成了Cu(Ⅱ), Zn(Ⅱ)和Ni(Ⅱ)配合物. 利用元素分析、红外光谱、紫外光谱、热分析等手段对配合物的结构进行了表征, 测定了Cu(Ⅱ)配合物的电化学性质. 结果表明, 配合物的化学组成为ML·nH2O(L=C13H15NO3, M=Cu(Ⅱ), Zn(Ⅱ), Ni(Ⅱ), n=1, 1, 2), 配合物具有相似的空间结构, 配体均以三齿进行配位; 电合成配合物的电化学效率Ef 接近0.5 mol/F[Zn(Ⅱ), Ni(Ⅱ)]和1.0 mol/F[Cu(Ⅱ)], Cu(Ⅱ)配合物中Cu(Ⅱ)L/Cu(Ⅰ)L电对的可逆半波电位Er1/2为-0.79 V.     

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.     

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.     

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.