铕和镧与吡啶－2，6－二甲酸配合物的NMR研究

合成了稀土铕、镧与吡啶－２，６二甲酸形成的二元配合物及铕与邻菲罗啉和吡啶－２，６二甲酸形成的三元配合物。经元素分析确定该配合物的组成分别为二元：Ｎａ３［Ｅｕ（ＤＰＣ）３］·２Ｈ２Ｏ，Ｎａ３［Ｌａ（ＤＰＣ）３］·２Ｈ２Ｏ；三元：ＮａＥｕ（ＤＰＣ）２·ｐｈｅｎ·４Ｈ２Ｏ。用核磁共振研究了配体与稀土的配位方式，讨论了诱导效应、屏蔽效应及稀土离子的顺磁性对配合物化学位移和ＮＭＲ谱图的影响。ＮＭＲ研究表明，三种配合物具有相似的对称结构和相同的化学位移变化规律。吡啶－２，６二甲酸中的羧酸以单齿配位（整个分子为三齿配位），二元配合物中，铕和镧的配位数均为９，三元配合物中，铕的配位数最低为８。     

铕和镧与吡啶—2,6—二甲酸配合物的NMR研究

合成了稀土铕，镧与吡啶－２，６－二甲酸形成的二元配合物及铕与邻菲罗啉和吡啶－２，６－二甲酸形成的三元配合物，经元素分析确定该配合物的组成分别为二元：Ｎａ３「Ｅｕ（ＤＰＣ）３」．２Ｈ２Ｏ，Ｎａ３「Ｌａ（ＤＰＣ）３」２Ｈ２Ｏ；三元：ＮａＥｕ（ＤＰＣ）２；ｐｈｅｎ．４Ｈ２Ｏ。用核磁共振研究了配体与稀土的配位方式，讨论了诱导效应、屏蔽效应及稀土离子的顺磁性对配合物化学位移和ＮＭＲ谱图的影响。     

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.     

吡啶-2,6-二甲酰胺衍生物Tb(Ⅲ)、Eu(Ⅲ)配合物的制备及荧光性能测试

从吡啶-2,6-二甲酸(L1)出发,合成了2种含有多个共轭体系和多齿的N2,N6-二(3-甲基吡啶)-2-取代吡啶-2,6-二甲酰胺(L2)配体和N2,N6-二对甲苯基吡啶-2,6-二甲酰胺 (L3) 配体;制备了化合物N2,N6-二(3-甲基吡啶)-2-取代吡啶-2,6-二甲酰胺(L2)与Tb(Ⅲ)和Eu(Ⅲ)的配合物,培养出了单晶.通过红外光谱、元素分析和X射线单晶衍射仪确定配合物的组成和结构.结果表明:在Tb(Ⅲ)配合物的稀溶液中,当溶液pH值为7时荧光强度最强,pH值大于或小于7荧光强度都逐渐减弱;当溶液pH为7时,N2,N6-二(3-甲基吡啶)-2-取代吡啶-2,6-二甲酰胺对Tb(Ⅲ)的荧光强度敏化远大于吡啶-2,6-二甲酸;N2,N6-二(3-甲基吡啶)-2-取代吡啶-2,6-二甲酰胺和吡啶-2,6-二甲酸与Eu(Ⅲ)形成稀的配合物溶液的荧光强度随pH值的增加而增大(pH 3～11).     

吡啶—2，6—二甲酸类配体稀土配合物的荧光性能

以13种配体分别与10余种稀土离子形成二元配合物, 研究其水溶液荧光强度 , 结果发现, 只有Tb3+和Eu3+有较强荧光, Dy3+和Sm3+只有非常弱的荧光, 而其他稀土离子不发光.荧光强度顺序除配体DPA为Eu3+＞Tb3+ ＞Dy3+＞Sm3+外, 其余配体的荧光强度顺序为Tb3+＞Eu3+＞D y3+＞Sm3+. 以数种4-位取代吡啶-2,6-二甲酸衍生物为配体, 与Tb3 +形成二元配合物体系, 研究了pH、溶剂等因素对体系荧光强度的影响, 测定了pH近中性情况下配合物体系的激发与发射光谱, 发光寿命等; 研究了3或4-位不同取代基对体系发光性能的影响. 结果表明 (1) 当pH值近中性时体系的发光性能最好; (2) 不同取代基对体系的发光性能也有较大的影响, 取代基为供电子基团时, 体系的发光性能要优于取代基为吸电子基团的发光体系; (3) 溶剂效应的影响对体系的发光性能影响较大, 其中低极性溶剂对体系的发光性能要优于高极性溶剂. 其中4-异丙氧基吡啶-2,6-二甲酸、 4 -乙酰氨基吡啶-2,6-二甲酸和3-乙酰氨基吡啶-2,6-二甲酸为Tb3+的理想敏化剂.     

[Cu(HDPC)_2]·(HO_x)_2·6H_2O的合成及晶体结构

铜是重要的生命元素,它与铁一样能起到输送氧气和电子载体的作用。把铜的配合物作为生物体内金属离子／酶／底物间相互作用的模拟研究一直十分活跃犤１～４犦。我们选取Cu?与吡啶－２,６－二甲酸（H２DPC）和８－羟基喹啉（HOx）,合成了配合物犤Cu（HDPC）２犦·（HOx）２·６H２O,并获得其单晶,测定了其晶体结构,讨论了存在于体系中的氢键作用。１实验部分１．１配合物的合成先将１mmolH２DPC用NaOH（１mmol·L－１）溶液调配成pH＝７．０的钠盐,然后滴加１０mL溶有１mmolHOx的９５％乙醇溶液,在搅拌下,上述混合液慢…     

噻吩甲酰三氟丙酮和4,5-二氮芴-9-酮及4,5-二氮芴-9-酮连氮铕(Ⅲ)三元配合物的合成和表征

合成了Ｅｕ（ＴＴＡ）３Ｌ１（Ⅰ）和［Ｅｕ（ＴＴＡ）３］２Ｌ２（Ⅱ）二种新的铕（Ⅲ）三元配合物（ＴＴＡ＝噻吩甲酰三氟丙酮一价阴离子、Ｌ１＝４，５－二氮芴－９－酮、Ｌ２＝４，５－二氮芴－９－酮连氮）。用元素分析、ＩＲ、ＵＶ和溶液荧光光谱对配合物进行了表征。探讨了溶剂对Ｅｕ（Ⅲ）三元配合物荧光光谱的影响，发现在ＣＨ３ＣＮ中Ｅｕ（Ⅲ）三元配合物发光效果最好，而溶剂ＤＭＦ会使配合物荧光减弱     

铜（Ⅱ）－4－（吡啶－2′－甲基）－1，4，7，10－四氮杂环十三烷－11，13－二酮－α－氨基酸（5－取代邻菲罗啉）三元配合物的稳定性研究

用ｐＨ法在２５．０±０．１℃，Ｉ＝０．１ｍｏｌ·ｄｍ－３ＫＮＯ３条件下，测定铜（Ⅱ）－４－（吡啶－２′－甲基）－１，４，７，１０－四氮杂环十三烷－１１，１３－二酮－α－氨基酸（５－取代邻菲罗啉）三元配合物的稳定常数；比较了带吡啶甲基二氧四胺大环配体和二氧四胺大环配体与Ｃｕ（Ⅱ）的配位能力、配位方式；研究了该三元体系配合物稳定性与配体α－氨基酸酸碱强度之间的直线自由能关系；探讨了Ｃｕ（Ⅱ）和５－取代邻菲罗啉之间的ｄ－ｐ反馈π键以及邻菲罗啉取代基Ｈａｍｍｅｔｔ诱导效应与该三元配合物稳定性之间的关系。讨论了４－（吡啶－２′－甲基）－１，４，７，１０－四氮杂环十三烷－１１，１３－二酮和４－（喹啉－２′－甲基）－１，４，７，１０－四氮杂环十三烷－１１，１３－二酮与Ｃｕｘｐｈｅｎ所形成配合物的不同空间结构及其对配合物稳定性产生的影响。     

吡啶-2,6-二甲酰腙类化合物及其Tb(Ⅲ)和Eu(Ⅲ)配合物的合成与荧光性能

吡啶-2,6-二甲酸经酯化,肼解得吡啶-2,6-二甲酰肼(2),(2)与芳香醛缩合得到了3个新的酰腙配体:吡啶-2,6-二甲酰肼苯甲醛腙(3a)、吡啶-2,6-二甲酰肼水杨醛腙(3b)和吡啶-2,6-二甲酰肼呋喃甲醛腙(3c),其结构经元素分析、IR、1HNMR和MS进行了确认。制备了吡啶-2,6-二甲酰肼与这三种新型配体的Tb(III)和Eu(III)配合物,并对配合物的溶液态的荧光性质进行了研究。结果表明,吡啶-2,6-二甲酰肼苯甲醛腙(3a)和吡啶-2,6-二甲酰水杨醛腙(3b)作为荧光敏化剂,对Eu3+和Tb3+的荧光敏化性能比吡啶-2,6-二甲酰肼以及大多数吡啶-2,6-二甲酸衍生物要好,是较理想的稀土荧光敏化剂,它们的稀土配合物在分子偶极矩较小的溶剂中荧光强度较强。     

铕(Ⅲ)-色氨酸-咪唑三元配合物的电化学行为研究

本文合成了铕（Ⅲ）－色氨酸－咪唑二元及三元配合物,并对配合物进行了红外光谱分析,确定了配合物的成键特征．应用循环伏安法研究了铕（Ⅲ）稀土离子、铕（Ⅲ）与色氨酸及咪唑混合溶液、铕（Ⅲ）二元及三元配合物在玻碳电极上的电化学行为．实验结果表明,在—０．４～—１．０Ｖ（ｖｓ．ＳＣＥ）电位扫描范围内,配体为非电活性物质,铕（Ⅲ）及其与配体的混合溶液以及配合物均显示了准可逆的电子迁移过程．     

Luminescence of Europium(III) Chelates with 4-(Arylethynyl)pyridines as Ligands

Some Spectral properties and luminescence intensities of Eu^III chelates with 4-(arylethynyl)pyridine-2,6-dicarboxylic acids 1 – 15 and 2,2′,2″,2′″-{[4-(arylethynyl)pyrridine-2,6-diyl]bis(methylenenitrilo)} tetrakis(acetic acids) 16 – 26 were measured both in H₂O and EtOH solutions for the purpose of developing suitable labels to be used in time-resolved luminescence-based bioaffinity assays (Tables 1 and 2). The substitution at the Ar group has a significant effect upon the observed luminescence intensities, excitation wavelengths, and decay constants of the complexes, Moreover, the changes in the environment cause great variation in those properties of certain Eu^III chelates.     

Interaction of pyridine‐ and 4‐hydroxypyridine‐2,6‐dicarboxylic acids with heavy metal ions in aqueous solutions

Interactions between pyridine‐2,6‐dicarboxylic acid and 4‐hydroxypyridine‐2,6‐dicarboxylic acid with Cu(II), Pb(II), and Cd(II) ions were characterized in aqueous solutions (20°C; I = 0.4 (KNO₃)) by means of dc‐polarography. In solutions with excess of ligand, Cu(II), Pb(II), and Cd(II) form 1:2 complexes with the tridentate dianion of pyridine‐2,6‐dicarboxylic acid (dipic²⁻) from weak acid to alkaline solutions. The values of log β₂ for Cu(II), Pb(II), and Cd(II) are 16.1, 11.8, and 11.0, respectively. The complexing ability of pyridine‐2,6‐dicarboxylic acid is higher in acid solutions and lower in alkaline solutions than that of 4‐hydroxypyridine‐2,6‐dicarboxylic acid. This difference is attributed to the OH‐group, which can deprotonate in basic pH. In acid solutions the OH‐group acts as an electron acceptor and reduces the electron donation available to the nitrogen atom in 4‐hydroxypyridine‐2,6‐dicarboxylic acid, whereas in alkaline solutions the OH‐group is deprotonated, and the deprotonated O₋ group acts as an electron donor and increases the coordination ability of the ligand. The triple‐deprotonated anion of 4‐hydroxypyridine‐2,6‐dicarboxylic acid (chel^3‐) forms a stable diligand complex with Cu(II), the stability constant logarithm being 21.5 ± 0.2.© 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:625–632, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10203     

Simultaneous spectrophotometric determination of atrazine and cyanazine by chemometric methods

Three novel ligands containing pyridine-2,6-dicarboxylic acid unit, trans-4 -(4'-methoxystyryl) pyridine-2,6-dicarboxylic acid, trans-4-(4'-(dimethylamino)styryl)pyridine-2,6-dicarboxylic acid, and trans-4-(4'-(diphenylamino)styryl)pyridine-2,6-dicarboxylic acid were synthesized and their complexes with Eu(III), Tb(III) ions were successfully prepared. The ligands and the corresponding metal complexes were characterized by means of MS, elemental analysis, IR, (1)H NMR and TG-DTA. The luminescence spectra of Eu(III) and Tb(III) complexes in solid state were studied. The strong luminescence emitting peaks at 615 nm for Eu(III) and 545 nm for Tb(III) can be observed. The applications in cell imaging of the europium and terbium complexes were investigated.     

Synthesis of Eu(III) and Tb(III) complexes with novel pyridine dicarboxylic acid derivatives and their fluorescence properties

Starting from pyridine-2,6-dicarboxylic acid (DPA), a series of novel pyridine-2,6-dicarboxylic acid derivatives were synthesized. In these compounds, 4-(hydroxymethyl)pyridine-2,6-dicarboxylate (4-HMDPA) and 4-[(bis-carboxymethyl-amino)-methyl]-pyridine-2,6-dicarboxylic acid (4-BMDPA) were used as multifunctional ligands to coordinate with Tb(III) and Eu(III) and the complexes were prepared. The fluorescence properties of the solid complexes and their solutions were investigated in detail. The results indicated that the weak election-withdrawing group 4-hydroxymethyl in 4-position of pyridine in 4-HMDPA could weaken the fluorescence intensity of the lanthanide complexes. The contradistinctive experimental results showed that the fluorescence intensities of these complexes are related to pH values of the aqueous solutions and the dipole moments of solvent molecules: in the neutral aqueous solutions, the fluorescence intensities of these complexes were strongest, while the dipole moments were lower when the fluorescence intensities were stronger. 4-BMDPA is the better sensitizer and may be used as time-resolved fluoroimmunoassay. __________ Translated from Chemical Journal of Chinese Universities, 2006, 27(3) (in Chinese)     

Remarkable tuning of the photophysical properties of bifunctional lanthanide tris(dipicolinates) and its consequence on the design of bioprobes

Derivatives of dipicolinic acid with a polyoxyethylene pendant arm at the pyridine 4-position have been functionalized for potential grafting with biological material. Four ligands with different terminal functions (alcohol, methoxy, phtalimide and amine) have been synthesized, which react with trivalent lanthanide ions Ln (III) to yield triple helical [Ln(L) 3] (3-) complexes, as shown by NMR and UV-vis titrations. The tris chelates display large thermodynamic stability with log beta 13 approximately 19-20 for all Eu (III) complexes for instance. Photophysical measurements reveal adequate sensitization of the metal-centered luminescence in the europium (eta sens = 33-72%) and terbium complexes, which is modulated by the nature of the terminal function. The lifetimes of the metal-centered excited states are long, up to 1.4 ms for [Eu(L) 3] (3-) and 1.6 ms for [Tb(L) 3] (3-) at room temperature, in line with hydration numbers essentially equal to zero. Quantum yields are as high as 29% for the [Eu( L ( NH2 )) 3] (3-) and 18% for the [Tb( L ( OH )) 3] (3-) tris chelates in water at physiological pH. These series of complexes demonstrate the extent of fine-tuning achievable for lanthanide luminescent probes and are simple models for investigating the effect of binding to biological molecules on the metal-centered luminescent properties.     

Synthesis of Novel Derivatives of Pyridine‐2,6‐dicarboxylic Acid

Two series of novel derivatives of pyridine‐2,6‐dicarboxylic acid with potential as polydentate ligands were synthesized from pyridine‐2,6‐dicarboxylic acid. All new compounds were characterized by NMR, MS, IR, and EA.     

铽与1-苯基-3-甲基-4-酰代吡唑啉-5-酮的三元配合物的合成、表征与荧光性能

合成了铽与1-苯基-3-甲基-4-异丁酰基吡唑啉-5-酮(HPMIBP)、1-苯基-3-甲基-4-苯甲酰基吡唑啉-5-酮(HPMBP)的四个三元配合物Tb(PMIBP)3.2H2O(A1), Tb(PMIBP)3.bpy(A2), Tb(PMBP)3.2H2O(B1)和Tb(PMBP)3.bpy(B2)(bpy=2, 2'-联吡啶)。用元素分析确定了它们的组成, 并用紫外-可见光谱、红外光谱、差热-热重谱对其进行了表征。研究了它们在固态和溶液中的荧光光谱, 并用频域法测定了它们在溶液中的荧光寿命, 结果表明A1和A2的荧光强度比相应的B1和B2强三个数量级, A2与A1或B2与B1相比, 荧光强度也有一定程度的增强,并且不同溶剂对其荧光强度和荧光寿命都有较大的影响。     

Synthesis of Eu(III) and Tb(III) complexes with novel pyridine dicarboxamide derivatives and their luminescence properties

A novel ligand, N2,N6-bis[2-(3-methylpyridyl)]pyridine-2,6-dicarboxamide (L2) and the corresponding Eu(III) and Tb(III) hydrochlorate complexes have been synthesized and characterized in detail based on elemental analysis, IR and NMR. The crystal and molecular structure of the complexes was determined by X-ray crystallography. The Eu(III) and Tb(III) ions were found to coordinate to the amido nitrogen atoms and pyridine nitrogen atoms. The luminescence properties of lanthanide complexes in solid state, in different solutions and in different pH value were investigated. The result shows that Tb(III) complexes exhibit more efficient luminescence than Eu(III) complexes, and the ligand (L2) is an excellent sensitizer to Tb(III) ion.