NH_4[RE(Ac)_4·H_2O]发光稀土配合物的研究

以乙酸和乙酸铵为配体,合成了新颖发光稀土配合物,通过元素分析、红外光谱、热重分析等手段对配合物进行了表征,确定其结构为NH4[RE(Ac)4.H2O](RE=Tb或Eu).结果表明,配合物中羧基以螯合、双齿和单齿方式与稀土离子配位;并通过荧光光谱分析、荧光寿命研究了其发光性能,配合物能发射强的稀土离子的特征荧光且有较长的荧光寿命.     

对—苯二甲酸邻菲罗啉铕镧配合物的红外光谱及荧光光谱研究

用对-苯二甲酸铵和邻菲罗啉与氯化铕和氯化镧在乙醇-水溶液中反应,合成了对-苯二甲酸邻菲罗啉铕镧异核稀土配合物,测定了配合物的C,H,N和稀土元素的含量、红外光谱、紫外光谱及荧光光谱,确定了配合物的组成。结果表明,羧基氧和邻菲罗啉氮原子均与稀土离子配位,桥联配体对-苯二甲酸根可有效的传送能量,不发光的镧离子对铕离子的发光有明显的增强作用。     

模板法合成稀土大环配合物

用模板法合成了一系列稀土大环配合物,通过元素分析、摩尔电导、红外光谱、核磁共振谱、热重.热差和紫外吸收光谱对其进行了结构表征.结果表明,稀土大环配合物的结构为:[REL(NO3)3]·nH2O(RE=Pr,Dy,Nd,n=3;RE=Sm,Eu,La,n=4;L=2,3:10,11-dibenzo-4,9-tetraoxo-13,15-bis[diene-2(4-hydfoxy-3-methoxypheny)]-1,5,8,12.tetraazacyclomdeca-1,12.dione),配合物的产率约为80%.在DMF溶液中配合物为非电解质.配合物中3个硝酸根均以双齿配位的方式与稀土配位,稀土配位数为10,并且含有3～4个结晶水分子.同时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自由配体的特征发射荧光.     

2,2′-(1,2-亚苯基二氧)二(N-苯基乙酰胺)及其稀土配合物的合成、表征与荧光性质

稀土;芳香族酰胺;配合物;合成;荧光性质     

含稀土三元配合物高分子纳米纤维的制备与荧光性质研究

将发光良好的稀土三元配合物Eu(TTA)3phen和Tb(AA)3phen复合到水溶性的聚合物PVP中.通过静电纺丝技术得到了具有荧光特性的聚合物纳米纤维,并用扫描电镜和透射电镜对产物的微观结构进行了研究.同时研究了其荧光激发和发射光谱及荧光寿命.荧光测试表明稀土配合物在聚合物纳米纤维中比其在粉末中有更高的发光强度及更长的荧光寿命,其原因可归结为聚合物链状结构使得配合物无辐射的分子运动的受限,聚合物纳米纤维为稀土配合物提供了一个稳定的环境.该纳米纤维在紫外激发光的照射下可以发射出很强的稀土配合物的特征红光和绿光.     

稀土-姜黄素-菲啰啉配合物荧光和抑菌活性研究

合成了稀土与姜黄素和1,10-菲啰啉的稀土三元配合物和稀土与姜黄素的稀土二元配合物, 通过元素分析、摩尔电导、热重-差热分析、 IR 、 UV-Vis 和1H NMR方法, 确定配合物的化学组成分别为: REL3L′及REL3 · 2H2O (RE=Sm, Eu, Dy, L=姜黄素, L′=1,10-菲啰啉). 同时研究了配合物在室温下的荧光性质, 结果显示稀土三元、 二元配合物都表现出配体(L)的特征发射且发射强度大于配体(L), 三元配合物的荧光强于二元配合物. 抗菌活性试验结果表明, 稀土三元、 二元配合物对枯草杆菌和大肠杆菌都表现出很好的抑制作用, 而且稀土三元配合物REL3L′对所选菌种的抑菌性明显强于稀土二元配合物REL3 · 2H2O和配体姜黄素.     

钕三元配合物-聚氨酯发光材料的合成与荧光性能研究

在无水乙醇中,以1,10-邻菲啰啉和酒石酸为配体,合成了钕-酒石酸-邻菲啰啉三元稀土配合物;利用三元稀土配合物中的两个-OH作为多元醇的活性基团,以二丁基二月桂酸锡为催化剂,与具有活性基团-NCO的甲苯-2,4-二异氰酸酯反应制备新的键合型含稀土及高分子的发光材料.通过元素分析、EDTA配位滴定分析、红外、紫外、热分析和荧光光谱分析,测定了三元配合物及发光材料的组成、结构、热稳定性和发光性能.结果表明,酒石酸中的羧基以桥联方式与钕发生配位,phen与稀土离子之间的能量传递是主要过程,配合物的最大吸收与pben相比略有红移;在207nm波长激发下,三元配合物及发光材料在440和527nm处均能发出较强的特征荧光,预计在新型有机电致发光器件(OLEDS)和发光油漆方面有着广阔的应用前景.     

氯化稀土与苯基羧甲基亚砜配合物的合成、表征及Eu(Ⅲ)配合物的发光

稀土配合物;荧光;氯化稀土与苯基羧甲基亚砜配合物的合成、表征及Eu(Ⅲ)配合物的发光     

吡啶-2,6-二甲酸衍生物及其Tb(Ⅲ)和Eu(Ⅲ)配合物的合成与荧光性质

以吡啶-2,6-二甲酸(DPA)为起始物,合成了4-羟甲基吡啶-2,6-二甲酸(4-HMDPA)和4-(N,N-二羧甲基氨基)亚甲基吡啶-2,6-二甲酸(4-BMDPA)两种新型多功能配体,并制备了DPA,4-HMDPA及4-BMDPA的Tb(Ⅲ)和Eu(Ⅲ)配合物,对配合物的固体和溶液态的荧光性质进行了研究. 结果表明,在吡啶4位引入弱吸电子基团4-羟甲基会减弱稀土配合物的荧光强度; 在水溶液中稀土配合物与溶液的pH值有着密切的关联,中性水溶液中荧光强度较大; 分子偶极矩较小的溶剂中稀土配合物荧光强度较强. 表明4-BMDPA是较理想的稀土荧光敏化剂.     

异核稀土双亚砜配合物的合成、表征和荧光性质

合成得到一系列异核土双乙烷配合物和异核稀土双乙烷与１,１０－啡咯啉的配合物,通过元素分析,电感耦合等离子体法,电导,红外和紫外光谱对配合进行了表征,并研究了这些配合物的固体和溶液的荧光光谱。     

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.