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.     

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.     

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     

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.     

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。     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.