Ag2 and Ag3 Clusters: Synthesis,Characterization, and Interaction with DNA

Subnanometric samples, containing exclusively Ag₂ and Ag₃ clusters, were synthesized for the first time by kinetic control using an electrochemical technique without the use of surfactants or capping agents. By combination of thermodynamic and kinetic measurements and theoretical calculations, we show herein that Ag₃ clusters interact with DNA through intercalation, inducing significant structural distortion to the DNA. The lifetime of Ag₃ clusters in the intercalated position is two to three orders of magnitude longer than for classical organic intercalators, such as ethidium bromide or proflavine.     

两种三齿多吡啶铜(Ⅱ)配合物的合成、表征及其与DNA的作用

本文合成了2个三齿多吡啶铜(Ⅱ)配合物[Cu(phpi)Cl₂]·H₂O和[Cu(tpy)Cl₂]·2H₂O(phpi=2-(苯并咪唑基-2)-1，10-邻菲咯啉，tpy=2，2:6′，2″-三联吡啶)，并通过元素分析、摩尔电导率、红外光谱、紫外光谱对其进行了表征。应用电子吸收光谱、荧光光谱和粘度法研究了配合物与DNA的相互作用。在抗坏血酸存在下，利用琼脂糖凝胶电泳方法研究了配合物对pBR322 DNA的切割作用并对其作用机理作了初步探讨。     

水溶性锌卟啉配合物的合成、表征及其与CTDNA的作用

合成了5,10,15,20-四[4-(3'-丙氧基吡啶溴化盐)苯基]卟啉(TPPBr)及其锌卟啉配合物TPPBr(Zn),用红外光谱、核磁共振和紫外光谱进行了表征.利用紫外-可见光谱、荧光光谱、圆二色谱和黏度实验研究了TPPBr(Zn)与小牛胸腺DNA(CTDNA)的相互作用,并计算了TPPBr(Zn)与CTDNA作用的表观键合常数为2.64×10⁵L/mol.进而证明了TPPBr(Zn)与CTDNA以外部自堆积和静电结合的混合模式作用.     

左旋多巴酪氨酰酪氨酸二肽的合成及与DNA的相互作用

采用Fmoc固相法合成了左旋多巴酪氨酰酪氨酸二肽(L-dopa-L-Tyr-L-Tyr), 并经RP-HPLC分离和纯化, 通过ESI-MS,¹H NMR和¹³C NMR表征了其结构. 采用紫外光谱、荧光光谱和琼脂糖凝胶电泳研究了左旋多巴(L-dopa)及L-dopa-L-Tyr-L-Tyr与DNA的相互作用. 结果表明, 随着L-dopa和L-dopa-L-Tyr-L-Tyr浓度的增加, 体系的紫外光谱呈减色效应; 根据Stern-Volmer方程可知荧光猝灭方式为静态猝灭; 琼脂糖凝胶电泳中, pUC18DNA的迁移速率变慢. 推测L-dopa和L-dopa-L-Tyr-L-Tyr与ctDNA作用模式为嵌入作用. 与L-dopa相比, L-dopa-L-Tyr-L-Tyr与DNA的相互作用更强.     

Cationic Lanthanide Luminescent Copolymer: Design,Synthesis and Interaction with DNA

Polymerizable rare earth complex Eu(AA)₃Phen was synthesized by complexion of europium ion, acrylic acid (AA), and 1,10-phenanthroline (Phen). The structure and fluorescence properties of the complex were studied by elemental analysis, ¹H-NMR spectroscopy, and fluorescence spectroscopy. Eu-containing copolymer poly(PEGMA-co-MMA-co-METAC-co-Eu(AA)₃Phen) (PPMMEu) was then synthesized by free radical copolymerization of Eu(AA)₃Phen and other functional monomers including poly(ethylene glycol) methyl ether methacrylate (PEGMA) and [2-(Methacryloyloxy) ethyl] trimethylammonium chloride (METAC). ¹H-NMR spectroscopy and fluorescence spectroscopy were used to characterize the copolymer and the interactions between the copolymer and DNA was investigated by TEM, fluorescence spectroscopy, and agarose gel electrophoresis. The desired luminescent cationic copolymer was successfully obtained. The copolymer can form micelles in water solution and can efficiently bind to DNA molecules through electrostatic interaction. The results suggest the potential use of PPMMEu in bioprobes and gene vectors.     

稀土-香兰素缩赖氨酸希夫碱配合物的合成、表征及其与DNA作用的研究

合成了香兰素缩赖氨酸希夫碱配体(HL)和15种香兰素缩赖氨酸希夫碱的稀土配合物REL(NO3)2.3H2O(RE=Y,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu),并通过元素分析、摩尔电导、热重分析、红外光谱、紫外光谱、核磁共振方法对配合物的组成和结构进行了表征。采用紫外光谱和荧光光谱方法初步研究了Nd,Tb,Yb,Lu这4种希夫碱配合物与DNA的相互作用,实验结果显示,随着DNA的加入,配合物在280 nm处的紫外吸收峰不断增强,同时配合物在418 nm左右的荧光发射峰随DNA浓度的增大均逐渐减小,说明配合物和DNA是以静电模式结合。     

Ag10Ti28‐Oxo Cluster Containing Single‐Atom Silver Sites: Atomic Structure and Synergistic Electronic Properties

Supported single‐atom catalysts have been emerging as promising materials in a variety of energy catalysis applications. However, studying the role of metal–support interactions at the molecular level remains a major challenge, primarily due to the lack of precise atomic structures. In this work, by replacing the frequently used TiO₂ support with its molecular analogue, titanium‐oxo cluster (TOC), we successfully produced a new kind of Ti‐O material doped with single silver sites. The as‐obtained Ag₁₀Ti₂₈ cluster, containing four exposed and six embedded Ag sites, is the largest noble‐metal‐doped Ti‐O cluster reported to date. Density functional theory (DFT) calculations show that the Ag₁₀Ti₂₈ core exhibits properties distinct from those of metallic Ag‐based materials. This Ti‐O material doped with single Ag sites presents a high ?_d and moderate CO binding capacity comparable to that of metallic Cu‐based catalysts, suggesting that it might display different catalytic performance from the common Ag‐based catalysts, for example, for CO₂ reduction. These results prove that the synergism of active surface metal atoms and the Ti‐O cluster support result in unique physical properties, which might open a new direction for single‐atom‐included catalysts.