一个高度减少的v(2)(3+) 单位,其金属对金属的结合顺序为3.5
F Albert Cotton1, Elizabeth A Hillard, Carlos A Murillo
1Department of Chemistry, Laboratory for Molecular Structure and Bonding, Texas A&M University, College Station, Texas 77842-3012, USA.
Journal of the American Chemical Society
|February 20, 2003
概括
研究人员合成了一种新型的复合物,具有独特的M(2)(3+) 核心. 这种偏磁性化合物表现出较短的V-V键和非局部化的电子,表明键次序为3.5.
科学领域:
- 无机化学 无机化学
- 材料科学 材料科学 材料科学
- 协调化学 协调化学
背景情况:
- 四叶片轮复合体在各种化学应用中都很重要.
- 在这样的复合体中,与的结合并未完全被理解.
- 之前的研究集中在V(2)(4+) 核心,使V(2)(3+) 核心的探索较少.
研究的目的:
- 为了分离和描述第一个带有V(2)(3+) 核心的四叶片轮复合体.
- 为了研究这种新型瓦纳物种的结构和电子特性.
- 了解V-V键和电子移位的性质.
主要方法:
- 通过减少使用KC的V(2)(DPhF)(4) 前体合成复合物.
- 由此产生的深绿色,偏磁性化合物的隔离和净化.
- 使用X射线衍射进行结构性表征.
- 使用电子磁共振 (EPR) 谱学的电子表征.
主要成果:
- 成功分离了K ((THF) ((3) [V ((2) ((DPhF) ((4)),这是第一个带有M ((2) ((3+) 核心的四叶片轮复合体.
- 确定V-V键距离为1.9295(8) Å,比V(2)(4+) 种更短.
- 在EPR光谱中观察到15行超细分离模式,表明未配对电子的脱局部.
结论:
- 合成的复合物代表了一类新的瓦纳轮化合物.
- 较短的V-V键和电子移位表明键顺序为3.5.
- 这项工作为减少的复合体中的电子结构和结合提供了新的见解.
更多相关视频
07:14Experimental Approaches for the Synthesis of Low-Valent Metal-Organic Frameworks from Multitopic Phosphine Linkers
Published on: May 12, 2023
06:53Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
相关概念视频
Ionic Bonding and Electron Transfer
Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence shell, and an anion (a negative ion) forms when a neutral atom gains one or more electrons in its valence shell. Compounds composed of ions are called ionic compounds (or salts), and their constituent ions are held together by ionic bonds: electrostatic forces of attraction between oppositely charged cations and anions.
Valence Bond Theory
Overview of Valence Bond Theory
Formation of Complex Ions
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
Properties of Transition Metals
Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3–12 are transition elements. The f-block elements, also called inner transition metals (the lanthanides and actinides), also meet this criterion because the d orbital is partially occupied before the f orbitals.
Coordination Number and Geometry
For transition metal complexes, the coordination number determines the geometry around the central metal ion. Table 1 compares coordination numbers to molecular geometry. The most common structures of the complexes in coordination compounds are octahedral, tetrahedral, and square planar.
Valence Bond Theory
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...
