化纯化协调聚合物:溶液中的和表面上的合成,光谱和电化学
S Bernhard1, K Takada, D J Díaz
1Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, USA.
Journal of the American Chemical Society
|October 18, 2001
概括
使用立体特异反应和铁 (II) 合成了多达60个重复单元的状协调聚合物. 循环二元化和STM成像证实了它们的螺旋结构和高顺序,具有类似于单体复合物的电化学特性.
科学领域:
- 协调化学 协调化学
- 聚合物科学 聚合物科学
- 超分子化学 超分子化学
背景情况:
- 嵌合式特皮里迪尔类型的配体是复杂架构的构建块.
- 立体特异合成对于控制聚合物性至关重要.
- 铁 (II) 复合物具有可调节的氧化还原特性.
研究的目的:
- 为了合成化纯粹的化协调聚合物.
- 描述聚合物的结构和螺旋性.
- 为了研究性氧化还原聚合物的电化学行为.
主要方法:
- 用于配体合成的立体特异性化.
- 用于反应监测的光谱摄影仪.
- 循环二元化和STM成像用于结构分析.
- 循环电压测量用于电化学研究.
主要成果:
- 我们成功地制备了纯净的桥接配体和奇拉协调聚合物.
- 在HOPG基板上形成了多达60个单位的高度排序的螺旋聚合物域.
- 圆形二重化证实了螺旋结构的绝对配置.
- 聚合物的电化学特性与单体复合物相似,具有独立的金属中心行为.
结论:
- 该研究表明,成功合成了高度有序的,性纯粹的性协调聚合物.
- 这些发现突显了这些材料在需要奇拉识别和氧化还原活性的领域的潜力.
- 金属中心的独立行为表明了分子电子学中的应用.
相关概念视频
Photochemical Electrocyclic Reactions: Stereochemistry
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
Complexation Equilibria: Overview
Complexation reactions take place when dative or coordinate covalent bonds form between metal ions and ligands. The compounds formed in these reactions are called coordination compounds. The number of bonds formed between the metal ion and the ligands is called its coordination number. Generally, most metal ions in an aqueous solution are solvated by water molecules and thus exist as aqua complexes.
The equilibrium constant of the complexation reaction is represented as the formation constant...
The equilibrium constant of the complexation reaction is represented as the formation constant...
Colloidal precipitates
The high insolubility of some precipitates can result in an unfavorable relative supersaturation. This can lead to colloidal particles with a large surface-to-mass ratio, where adsorption is promoted. For instance, in the precipitation of silver chloride, silver ions are adsorbed on the surface of the colloidal particles, forming a primary layer. This layer attracts ions of opposite charge (such as nitrate ions), forming a diffuse secondary layer of adsorbed ions. This electric double layer...
Mass Spectrometry: Complex Analysis
Mass spectrometry is an important technique for the identification of pure compounds. However, it has some limitations for the analysis of complex mixtures, often due to excessive fragmentation making the spectrum too complicated to decipher. Mass spectrometry can be combined with suitable separation methods in sequence, forming hyphenated methods, which are useful in the analysis of complex mixtures.
GC–MS is a powerful hyphenated method commonly used in forensics and environmental...
GC–MS is a powerful hyphenated method commonly used in forensics and environmental...
Analyte Adsorption and Distribution
In certain chromatographic separations, solutes transfer between the mobile phase and the stationary phase via sorption, which typically refers to the process of adsorption. For many chromatographic systems, the sorption process often depends on the polarity of the compounds—an expression of the overall dipole moment within the molecule. During the separation process, there is competition between the solute and solvent for adsorption to the stationary phase. Highly polar compounds and solvents...
Affinity Chromatography
Affinity chromatography is a powerful technique extensively utilized for separating and purifying specific biomolecules from complex mixtures. It capitalizes on the highly selective binding between an analyte and its counterpart, such as antibody-antigen interactions. The counterpart is immobilized on the stationary phase, forming an affinity column. The stationary phase typically consists of solid support, such as agarose or porous glass beads, immobilizing the affinity ligand. The mobile...


