铕(Ⅲ)-二苯甲酰甲烷-聚(苯乙烯-丙烯酸)配合物及其发光性质研究

研究了铕(Ⅲ)和二苯甲酰甲烷(HDBM)形成的有机配合物与聚(苯乙烯-丙烯酸)(PSAA)发生配位反应得到配位聚合物Eu(Ⅲ)-DBM-PSAA。红外光谱、紫外光谱、X光电子能谱的测试表明了Eu^3^+分别与PSAA,DBM^-发生配位,元素分析和电导率测定结果证明了一个Eu^3^+分别与PSAA中三个链节的羧基和一个DBM^-发生配位。从而得到该配合物的结构并对其荧光性进行研究,配位聚合物不能溶于普通有机溶剂,只能溶于丙三醇/异丙醇混合溶剂常温下配合物在紫外光下发出强的红光,主要是Eu离子的^5D0→^7F2的跃迁。     

含稀土铕(Ⅲ)配位聚合物的研究——铕(Ⅲ)噻吩甲酰三氟丙酮苯乙烯丙烯酸共聚物的研究

研究了铕 (Ⅲ )和噻吩甲酰三氟丙酮 (HTTA)形成的有机配合物与苯乙烯 丙烯酸共聚物 (PSAA)在不同pH值时发生配位反应得到配位聚合物NaEu(Ⅲ ) TTA PSAA的 3种样品 (a)、(b)、(c) .红外光谱、紫外光谱、X光电子能谱、DTA TG等测试手段证实Eu3+ 分别与PSAA、TTA- 发生配位 .元素分析和电导率测定结果证明了配位组成和结构在不同的pH条件下发生变化 .结果表明 ,配合物试样 (a)、(b)、(c)中Eu3+ 的含量分别为11 89%、12 5 5 %和 13 4 1% .由于配合物中存在着Eu3+ 分别与TTA- 和PSAA分子中羧基的配位作用并进一步交联 ,因此配合物样品均不溶于大部分有机溶剂 ,只能溶于N ,N 二甲基甲酰胺和丙三醇和异丙醇的混合溶剂 ,而且耐热性能均提高 .该配合物均是褐色固体 .荧光光谱表明 ,样品在常温、紫外光下发出强的红光 ,主要是Eu离子的5D0 →7F2 的跃迁 .讨论了溶剂、pH值对配合物荧光强度的影响 .当pH =10时 ,合成的配合物有最好的荧光性质 .     

新型铕双β-二酮红光材料的合成与发光性质

通过分子设计,合成了一种新颖的双β-二酮有机配体9-乙基-3,6-二（乙酰基-3-苯甲酰基）咔唑（H2L）及其铕配合物,红外光谱和电子光谱表明Eu^3＋与H2L发生配位。配合物的溶液荧光光谱不仅有613 nm处的中心离子Eu^3＋的特征红光,属^5D0→^7F2跃迁带,还有445nm处配体的宽带蓝色发光,属H2L^＊→H2L跃迁带,而配合物的光致发光光谱只有611 nm处为中心离子Eu^3＋的特征红光,属^5D0→^7F2跃迁带,峰形尖锐,半峰宽仅7 nm,单色性好,表明该固体铕双β-二酮配合物是一种潜在的红色发光材料。     

对称吡啶双酰胺及其稀土配合物的合成、表征与荧光性质的研究

以元素分析、红外光谱、差热及核磁进行表征了配体及其五种稀土（La^3＋,Eu^3＋,Tb^3＋,Gd^3＋,Yb^3＋）配合物,确定了其组成,研究了部分配合物的固态荧光.同时以低温磷光光谱确定了配体的三重态能级为22989 cm^-1,研究了配体与稀土离子的能级匹配情况,详细讨论了配合物的发光性能.结果发现,铽配合物能发出很强的特有荧光,而铕配合物所发荧光很弱,说明配体L与Tb^3＋ 的^5D4匹配.对于Tb^3＋而言,当2000 cm^-1〈ΔE（T-^5D4）〈3000 cm^-1时,稀土铽离子发出强的荧光;对于Eu^3＋ 而言,ΔE（T-^5D1）超过3000 cm^-1时,则几乎不发荧光.     

新氮杂冠醚稀土配合物的制备、表征及其荧光性质

合成了一新的大环氮杂冠醚及其稀土配合物,并通过元素分析、摩尔电导、热分析及红外的测定对配合物进行了表征。结果表明,冠醚配体上的C和N原子均参与配位,并推测了配合物的可能组成。室温下研究了配合物的固体及在溶液中的荧光光谱。固态时Sm^3 ,Eu^3 ,TB^3 ,Dy^3 的冠醚配合物均有较强荧光,其中Tb^3 的荧光强度最高,表明冠醚配体三重态的能量与Tb^3 的振动能级更为匹配。在Eu^3 配合物中,强度比η(^5D0→^7F2/^5D0→^7F1)=5.3,表明Eu^3 处于一非对称配位环境中。     

1-(2-羟基苯基)-3-苯基-1,3-丙二酮及其铕(Ⅲ)配合物的合成和发光研究

以邻羟基苯乙酮和苯甲酰氯为原料, 经过酯化反应、 Fries重排合成了1-（2-羟基苯基）-3-苯基-1,3-丙二酮（HPPPD）及其与铕（Ⅲ）的配合物, 并通过IR, 热重-差热分析和^1H-NMR谱对其进行了表征. 研究了酚羟基的引入对稀土配合物发光性能的影响. 结果表明该配体与铕（Ⅲ）形成的配合物发出很强的铕（Ⅲ）的特征荧光, 并且以邻菲罗啉为第二配体的三元配合物的荧光强度明显高于二元配合物. 但是, 配体HPPPD与铽（Ⅲ）、钐（Ⅲ）和镝（Ⅲ）等形成的配合物, 无论是二元的, 还是三元的发光均很弱. 这是由于该配体的能级与不同稀土离子能级匹配程度的差别所致.     

两步溶胶-凝胶法于SiO2/聚合物杂化基质中原位合成铕的三元配合物及其发光性质

采用两步溶胶－凝胶过程制备了含铕的三元配合物的凝胶。荧光激发光谱证实于ＳｉＯ２基质中原位合成了铕的配合物。含铕配合物的杂化材料发出铕的特征荧光，与相应的纯配合物溶于乙醇相比，铕离子具有较长的荧光寿命。     

溶剂和冠醚结构对铕冠醚配合物的氧化还原电子转移性质的影响

用循环伏安法在二氯甲烷,乙腈,丙酮,甲醇,二甲基甲酰胺和二甲亚砜等有机溶剂体系中研究了硝酸铕与不同冠醚配合物的电还原反应.溶剂介质和冠醚结构对Eu^3+冠醚配合物氧化还原反应有显著影响.在弱配位溶剂中冠醚的配位作用稳定了Eu^2^+,使Eu^3^+的还原电位向阳极方向移动200mV左右.由于强配位溶剂的作用,体系还原反应可能成为EC机制.同一冠醚配合物在不同弱配位溶剂中S差别不大,但在强配位溶剂中其S明显下降.同时,电还原反应的E~1/2越负,S也越小.     

一种新型铕(Ⅲ)三元配合物的合成与电致发光

合成了一种含有空穴传导基团三苯胺、电子传导基团嗯二唑的新型配体（EtPOTIP）及其铕（Ⅲ）的三元配合物Eu（DBM）,EtPOTIP,通过^1HNMR、IR、元素分析及质谱对它们的结构进行了表征．对配体和配合物的吸收光谱及光致发光光谱研究结果表明：配体和配合物对近紫外光有强烈吸收,配合物在近紫外光激发下发出强的Eu^3＋特征红光,荧光量子效率为0．48;热分析显示配合物具有高的热稳定性,表明合成的配合物是一种优良的多功能红色发光材料。制作了相应的明亮电致发光器件,显示EtPOTIP同时具备空穴传导和电子传导性能,EtPOTIP在配合物中的存在显著改善了器件的电致发光性能。     

铽（III）-噻吩甲酰三氟丙酮-电化学聚合漆酚配合物的研究

研究了铽（III）和噻吩甲酰三氟丙酮（HTTA）形成的配合物与电化学聚合方 法得到的聚合漆酚（EPU）发生配位反应及pH = 10.2时形成配合物Tb(III)-TTA- EPU的组分和结构。红外光谱、X光电子能谱的测试表明Tb~(3+)分别与EPU，TTA~- 发生配位。元素分析和电感偶合等离子体发射光谱（AES）测定结果证明了每个 Tb~(3+)分别与EPU分子中1个链节单元的羟基和3个TTA~-发生配位，从而得到配合 物的结构。动态机械热分析（DMTA）表明发生配位反应后该配合物进一步交联，从 而难溶于大部分有机溶剂，其玻璃化转变温度和耐热性能均得到很大提高。我们对 其荧光性质进行了研究，发现常温下配合物在紫外光下发生强的荧光，主要是Tb~ (3+)离子的~5D_4→~7F_5的跃迁。讨论了溶剂、pH值对配合物荧光强度的影响。当 pH = 10.2时，合成的配合物有最好的荧光性质。     

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.     

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.     

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.     

Catalyst free,visible-light promoted photoaddition reactions between C60 and N-trimethylsilylmethyl-substituted tertiary amines for synthesis of aminomethyl-1,2-dihydrofullerenes

An efficient and benign method for the preparation of aminomethyl-substituted fullerenes has been developed. The process, involving catalyst free, visible-light irradiation of 10% EtOH-toluene solutions containing fullerene C₆₀ and N-trimethylsilylmethyl-substituted amines by using a 20 W compact fluorescent lamp, leads to formation of aminomethyl-substituted fullerene adducts in a highly efficient manner. The photoaddition reaction takes place via a pathway initiated by visible light absorption by C₆₀, followed by SET from the amine to the triplet excited state of C₆₀. Ethanol-promoted desilylation of the resulting a minimum radical then generates the corresponding α-amino radical which couples with the C₆₀ radical anion to form the anion precursor of the fullerene adducts. The new approach using visible-light takes place under mild conditions and it does not require the use of photocatalysts. Thus, the method developed in this effort could broadens the range of functionalized fullerene derivatives that can be readily prepared.     

Highly efficient and stereoselective cycloaddition of nitrones to indolyl- and pyrrolylacrylates

The reactions of various nitrones with indolyl- and pyrrolylacrylates proceeds regioselectively with high diastereoselectivity in the case of aldonitrones, and represents an effective method for obtaining new indolyl- and pyrrolyl-substituted isoxazolidine carboxylates stabilized by weak (CH?O) and moderate (NH?N) strength intramolecular hydrogen bonding. The resulting cycloadducts exhibit promising in vitro anti-influenza activities.     

Transition metal-free direct amination of benzoxazoles using formamides as nitrogen sources

A transition metal-free method for the direct amination of benzoxazoles using formamides as nitrogen sources is reported, which was mediated by an inexpensive and environmentally friendly tetrabutylammonium iodide/tert-butyl hydroperoxide system and gave the 2-aminobenzoxazole derivatives with moderate to good yields.     

l-Proline-catalyzed five-component domino reaction leading to multifunctionalized 1,2,3,4-tetrahydropyridines

Multifunctionalized 1,2,3,4-tetrahydropyridines are concisely synthesized in good yields via l-proline-catalyzed or l-proline/FeCl₃-cocatalyzed one-pot multicomponent reactions (MCRs). The MCRs involve a domino hydroamination/prins reaction/Mannich-type reaction/intramolecular dehydration-cyclization process. The molecular structure of 5baa, one of multifunctionalized 1,2,3,4-tetrahydropyridines, was confirmed by single-crystal X-ray diffraction.     

Studies of Photoionization of CF3 I by Femtosecond Time-resolved Mass Spectrometry

The multi-photon dissociative photoionization dynamics of CF3I has been studied with femtosecond two-color pump-probe time of flight mass spectra at a pump pulse of 265 nm and a probe pulse of 398 nm. The life constants of CF3I+ and its fragment ions CF3+ and I+ are obtained as (96±7), (198±130) and (167±6)fs, respectively. The multi-photon dynamics leading to these ions differ. CF3I+ corresponds to a (1+2′) transition with one-photon pump excitation to the A band of CF3I. CF3+ are mainly formed by a tow-photon probe excitation to the CF3+ with subsequent dissociation of parent ions. I+ are produced in (2+2′) combined with (1+1′+2′) process. The results provide information on the multi-photon pathways involved.