齐聚苯胺修饰的三联吡啶铁配合物的合成及其光谱和电化学性质

合成了一系列齐聚苯胺修饰的三联吡啶铁配合物,研究了齐聚苯胺链长、不同取代基等对配合物光谱性质和氧化还原性质的影响。 结果表明,相对于配合物[Fe(TPY)₂]²⁺(TPY:三联吡啶),供电子齐聚苯胺单元的引入,使得修饰基团与配合物中心核[Fe(TPY)₂]²⁺之间形成了强的D-A体系,导致配合物¹MLCT吸收波长显著红移至594 nm,且摩尔吸光系数增加近5倍。 配合物同时具有基于金属中心、三联吡啶配体和齐聚苯胺单元的多个氧化还原过程,强拉电子取代基使齐聚苯胺单元氧化还原峰简并且峰电势明显正移,而正丁基取代基对氧化还原峰电势的影响较小。     

联三吡啶配体及其衍生物合成进展

金属-配体间的配位作用是超分子化学中最重要的相互作用之一, 寡聚吡啶配体可以与许多过渡金属离子配位, 形成具有独特磁、光物理和电化学性质的过渡金属络合物, 因此联三吡啶配体的合成及其过渡金属络合物性能研究引起化学家的广泛关注. 综述了联三吡啶配体及其衍生物的合成方法, 主要包括成环缩合反应、过渡金属催化的偶联反应以及其它方法, 并选取具有代表性的实例对联三吡啶配体的结构和合成方法进行详细地阐述.     

Synthesis,Crystal Structure and Photoluminescence of a One-dimensional Zinc(Ⅱ)Coordination Polymer with Substituted Terpyridine

<正>The title compound,[Zn(4-pytpy)(NO_3)_2](4-pytpy=4'-(4-pyridyl)-2,2':6',2"- terpyridine)1,has been synthesized by the solvothermal reaction of Zn(NO_3)_2·6H_2O with 4-pytpy in CH_3OH solution.It crystallizes in the triclinic system,space group P_1~-with a=8.358(6),b= 11.121(8),c=11.374(8)(?),α=74.226(11),β=74.532(11),γ=83.085(12)°,M_r=499.74,V= 979.3(12)(?)~3,Z=2,D_c=1.695 g/cm~3,F(000)=508,μ=1.309 mm~(-1),the final R=0.0547 and wR= 0.1588.X-ray crystal structure analysis revealed that the Zn~Ⅱis hexa-coordinated by two oxygen atoms from two nitrate groups and four nitrogen atoms,three of which are from the tridentate domain of one 4-pytpy and the other from the monodentate domain of another 4-pytpy.4-pytpy as a bridging ligand connects Zn~Ⅱinto a one-dimensional coordination polymer.     

Wire-type ruthenium(II) complexes with terpyridine-containing [2]rotaxanes as ligands: Synthesis, characterization, and photophysical properties

[2]Rotaxanes based on the 1,2-bis(pyridinium)ethane subset[24]crown-8 ether motif were prepared that contain a terminal terpyridine group for coordination to a transition-metal ion. These rotaxane ligands were utilized in the preparation of a series of heteroleptic [Ru(terpy)(terpy-rotaxane)]2+ complexes. The compounds were characterized by 1D and 2D 1H NMR spectroscopy, X-ray crystallography, and high-resolution electrospray ionization mass spectrometry. The effect of using a rotaxane as a ligand was probed by UV/Vis/NIR absorption and emission spectroscopy of the Ru(II) complexes. In contrast with the parent [Ru(terpy)(2)]2+ complex, at room temperature the examined complexes exhibit a luminescence band in the near infrared region and a relatively long lived triplet metal-to-ligand charge-transfer (3MLCT) excited state, owing to the presence of strong-electron-acceptor pyridinium substituents on one of the two terpy ligands. Visible-light excitation of the Ru-based chromophore in acetonitrile at room temperature causes an electron transfer to the covalently linked 4,4'-bipyridinium unit and the quenching of the MLCT luminescence. The 3MLCT excited state, however, is not quenched at all in rigid matrix at 77 K. The rotaxane structure was found to affect the absorption and luminescence properties of the complexes. In particular, when a crown ether surrounds the cationic axle, the photoinduced electron-transfer process is slowed down by a factor from 2 to 3. Such features, together with the synthetic and structural advantages offered by [Ru(terpy)2]2+-type complexes compared to, for example, [Ru(bpy)3]2+-type compounds, render these rotaxane-metal complexes promising candidates for the construction of photochemical molecular devices with a wire-type structure.     

Tuning the thermotropic and lyotropic properties of liquid-crystalline terpyridine ligands

A rational synthetic strategy is developed to provide compact and simple terpyridine (terpy) mesogens that show liquid-crystallinity both as pure compounds and in organic solution (amphotropic compound). The use of a central 4-methyl-3,5-diacylaminophenyl platform equipped with two lateral aromatic rings, each bearing three appended aliphatic chains, allows connection of a 2,2':6',2'-terpyridine fragment through a polar group such as an ester, amide, or flat conjugated alkyne linker. For the T(12)ester and T(12)amide scaffolds, the mesophase is best described as a lamellar phase, in which the molecules self-assemble into columnar stacks held together in layers. In the T(12)amide case, the additional amide link results in significant stabilization of the lamellar phase. The driving forces for the appearance of columnar ordering are the hydrogen-bonding interactions of the amide groups, which induce head-to-tail pi-stacking of the terpy subunits. Replacing the polar linker by a nonpolarized but linear alkyne spacer, as in the T(12)ethynyl compound, provides a columnar mesophase organized in a rectangular lattice of p2gg symmetry. In this arrangement, two nondiscotic molecules arranged into dimers by hydrogen bonding and pi-pi stacking pile up in a head-to-tail manner to form columns. In addition, the T(12)amide compound proves to be an excellent gelator of cyclohexane, linear alkanes, and DMSO. The resulting robust and transparent gels are birefringent and formed by large aggregates that are readily aligned by shear-flow. TEM and freeze-fracture microscopy reveal that the gels have an original layered morphology made of fibers.     

含茂铁基三联吡啶钌功能分子的光电性质*

多吡啶钌配合物在光化学、光物理、电化学、电子转移、能量转移、分子组装和分子识别等研究领域都扮演着非常重要的角色。茂铁基具有化学稳定性、氧化还原活性、富电子性和结构易修饰等特点,使其在功能分子的设计与合成等领域得到广泛的应用。结合茂铁的电化学活性和[Ru(tpy)₂]²⁺的光学活性,在[Ru(tpy)₂]²⁺分子中三联吡啶的4′位上引入茂铁基,可以构筑性能优良的光电功能分子。本文介绍了近年来含茂铁基（尤其是具有扩展共轭体系的茂铁炔基或茂铁苯炔基）三联吡啶钌光电功能分子的研究进展,并结合本课题组的研究成果探讨了炔基的引入、炔基位置的不同和炔基长度（由单炔基到双炔基）的变化对该类化合物光电性质的影响。     

基于三联吡啶/苯三羧酸类配体构筑的两个配合物的合成、结构和性质

基于H3tbtd、H3bbta和bpy配体在水热条件下合成了配位聚合物{[Co3(tbtd)2(bpy)2(H2O)]·5H2O}n(1)和配合物[Cd2(Hbbta)(bpy)3(C2O4)(H2O)](2)(H3tbtd=4?(2,4,6?三羧基苯基)?2,2′,6′,2″?三联吡啶,H3bbta=1?氟?2,4,6?苯三酸,bpy=2,2′?联吡啶),并用元素分析、红外光谱、X射线单晶衍射等对其进行了表征。配聚物1为二维网状结构,基于丰富的氢键作用扩展形成三维超分子网结构。配合物2为双核结构,相邻的双核结构通过吡啶环之间的π…π堆积作用和氢键作用扩展为二维超分子网状结构。配聚物1在紫外光照射下对染料甲基橙(MO)的降解具有光催化活性,对紫外光催化具有良好的稳定性。此外还研究了配合物2的荧光性质和配合物1~2的热稳定性。     

Ratiometric Fluorescent Determination of the Zinc Ion Using a Terpyridine Derivative

Zinc is essential for normal growth and development, and hence selective recognition and detection for zinc has been a significant area of research. Here 4′-(4-methoxyphenyl)-2,2′:6′,2″-terpyridine is described for the ratiometric fluorescence quantification of zinc ion with high selectivity. The fluorescence of 4′-(4-methoxyphenyl)-2,2′:6′,2″-terpyridine at 406?nm was quenched in the presence of zinc, and a new emission band appeared at 452?nm. The ratiometric method for the determination of zinc ion was based on the dual fluorescence measurements at 406 and 452?nm. This fluorescence response is caused by the formation of a 1:1 complex between 4′-(4-methoxyphenyl)-2,2′:6′,2″-terpyridine and the zinc(II) ion. The analytical figures of merit for the protocol were obtained. The linear dynamic range extended for zinc concentrations from 3.0 to 40.0?µmol/L with a limit of detection of 0.28?µmol/L. Zinc was determined in water with satisfactory results.     

Electrocatalytic activity in sensing of nitrite by films produced by electropolymerization of [Fe(Br-ph-tpy)2]2+

Nitrite is a preservative agent broadly used in the food industry. Its excessive consumption can cause several diseases including cancer. Thus, the development of sensors for nitrite is indispensable for strict nitrite level control in industrialized products and consequently for human welfare. Herein, is presented a study of the modification of electrodes by electropolymerization of [Fe(Br-ph-tpy)₂](PF₆)₂ and its use as electroactive films in sensing of nitrite. The films were characterized by cyclic voltammetry, electrochemical quartz crystal microbalance, atomic-force microscopy and they were employed in electroanalytical experiments. The film obtained by electropolymerization exhibited some fibers dispersed on the substrate, reflecting the formation polymers on the surface of the electrode. The electrodes were further improved by drop casting a film of the complex on a glass carbon electrode, and then performing the electropolymerization of the complex. An increase in stability and a 41% enhancement of the electrocatalytical response for nitrite ions have been observed, in comparison with the bare electrode.