较重的性土和异金属s-块"ate"复合物中的二胺氧联体:固态结构和动态溶液相行为
Matthew D Haynes1, Andrea O'Reilly2, Alice J M Poole1
1Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK. zoe.turner@earth.ox.ac.uk.
Dalton transactions (Cambridge, England : 2003)
|February 12, 2025
概括
这项研究详细介绍了新的土金属复合物,使用灵活的二胺氧联体. 研究人员探索了它们的结构,溶液动力学和异金属胺形成,揭示了对s块化学的洞察力.
科学领域:
- 无机化学 无机化学 有机化学
- 有机金属化学 有机金属化学
- 材料科学 材料科学 材料科学
背景情况:
- 对s块金属复合物的合成和表征对于理解其多样化的化学性质至关重要.
- 化配体在稳定反应性金属中心和影响复杂结构方面发挥着至关重要的作用.
- 探索较重的土金属 (Ca-Ba) 为协调化学的周期性趋势提供了洞察力.
研究的目的:
- 为了合成和表征较重的土金属的新型中性和异金属s-block"ate"复合物.
- 研究这些复合物的固态结构和溶液相动态.
- 为了比较由di(amido) siloxane连接体支持的复合体与使用不同连接体骨干的复合体的特性.
主要方法:
- 用原始溶解反应来合成二次性性土复合物 [(NON-DippL) Ae]2.
- 复合物被转化为单体添加物在四水富兰 (thf).
- 通过涉及KN'和或土前体的反应合成异金属Ae/K胺"ate"复合物,随后进行结构分析 (包括X射线衍射) 和溶液相研究 (NMR,热力学).
主要成果:
- 三维性土复合物,[(NON-DippL) Ae]2 (Ae = Ca, Sr, Ba),已经成功地准备好.
- 在thf中形成了单体添加物,[(NON-DippL) Ae(thf) n].
- 合成了异金属复合物[{NNO-DippL}Mg{μ-N'''K}和[{NON-DippL}Ae{μ-N''K} (Ae=Ca,Sr,Ba),它们作为固态的1D协调聚合物存在.
- 复合体8具有重新排列的NNO联结体,而复合体9-11保留了NON联结体.
- 溶液研究揭示了可逆的KN'''从9-11复合体中解离,并阐明了热力学参数.
结论:
- 二胺氧联体有效地支持较重的土金属复合体中的多种结构和溶液动力学.
- 异金属Ae/K复合体表现出独特的协调聚合物结构,由K+-aryl相互作用驱动.
- 连接体的灵活性和金属的大小影响结构结果和反应性,为s块化学提供可调节的特性.
相关概念视频
Metal-Ligand Bonds
20.5K
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
20.5K
Structural Isomerism
19.1K
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
19.1K
Valence Bond Theory
8.4K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
8.4K
Complexation Equilibria: The Chelate Effect
421
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
421
Complexation Equilibria: Factors Influencing Stability of Complexes
319
In complexation reactions, metal cations are the electron pair acceptors, and the ligands are the electron pair donors. The stability of the metal complexes depends primarily on the complexing ability of the central metal ion and the nature of the ligands. Generally, the complexing ability of the metal ion depends on the size and charge of the ion. As the metal ion size increases, the stability of the metal complexes decreases, provided that the valency of the metal ion and the ligands remain...
319
Complexometric Titration: Ligands
878
Different monodentate and polydentate ligands are used as complexing agents in complexometric titration reactions. The formation of complexes by mono- and bidentate ligands involves two or more intermediate steps, limiting their use as complexing agents. In comparison, polydentate ligands can form complexes with metal ions in a single-step process, facilitating sharper end points. This means polydentate ligands, such as amino carboxylic acid derivatives, are most commonly employed in...
878


