稳定,单一结合的Pd2(6+) 化合物的高产合成
F Albert Cotton1, Igor O Koshevoy, Pascual Lahuerta
1Department of Chemistry, Laboratory for Molecular Structure and Bonding, P.O. Box 30012, Texas A&M University, College Station, Texas 77842-3012, USA. cotton@tamu.edu
Journal of the American Chemical Society
|October 19, 2006
概括
研究人员开发了一种新方法,用于合成具有单键Pd2核的罕见 (III) 化合物. 碳酸盐联结体上的电子捐赠组增强了化合物的稳定性和产量.
科学领域:
- 无机化学 无机化学
- 有机金属化学 有机金属化学
- 协调化学 协调化学
背景情况:
- 的化学性质对于催化和材料科学至关重要.
- 低价值团的合成,特别是那些具有金属-金属键的团,带来了独特的挑战.
- 了解化合物的电子结构和稳定性是它们应用的关键.
研究的目的:
- 建立具有单一结合Pd2(6+) 核的二化合物的一般合成途径.
- 研究连接体替代剂对这些复合物的稳定性和产量的影响.
- 描述合成化合物的电子配置和结构性质.
主要方法:
- 双化合物的一般合成,其公式为R,S-cis-Pd2(C6H4PPh2)2(O2CR) 2Cl2.2.
- 碳酸联体中基组 (R) 的变化,以研究电子效应.
- 通过X射线晶体学来确定Pd-Pd键距离.
- 密度函数理论 (DFT) 计算以阐明电子配置.
主要成果:
- 成功开发了一种用于合成单键Pd2(6+) 核心的二化合物的通用方法.
- 化合物表现出高稳定性和产量,当电子捐赠组存在于碳酸盐连接体上时.
- 特定的Pd-Pd距离被确定为二磁性化合物 (例如,2.5434(4) Å对于R=CF3,2.5241(9) Å对于R=CMe3).
- DFT计算显示了sigma2pi4delta2delta*2pi*4.4的电子配置.
结论:
- 该研究提出了稳定的 (III) 化合物的罕见例子.
- 开发的合成方法为新型团化合物提供了一条途径.
- 这些发现有助于理解低价值复合物的金属-金属结合和电子结构.
相关概念视频
Hybridization of Atomic Orbitals II
sp3d and sp3d 2 Hybridization
Molecular Orbital Theory II
Molecular Orbital Energy Diagrams
Preparation and Reactions of Sulfides
Sulfides are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohol. Like ethers, sulfides also consist of two hydrocarbon groups bonded to the central sulfur atom. Depending upon the type of groups present, sulfides can be symmetrical or asymmetrical. Symmetrical sulfides can be prepared via an SN2 reaction between 2 equivalents of an alkyl halide and one equivalent of sodium sulfide.
π Molecular Orbitals of 1,3-Butadiene
Conjugated dienes have lower heats of hydrogenation than cumulated and isolated dienes, making them more stable. The enhanced stabilization of conjugated systems can be understood from their π molecular orbitals.
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...
Cycloaddition Reactions: Overview
Cycloadditions are one of the most valuable and effective synthesis routes to form cyclic compounds. These are concerted pericyclic reactions between two unsaturated compounds resulting in a cyclic product with two new σ bonds formed at the expense of π bonds. The [4 + 2] cycloaddition, known as the Diels–Alder reaction, is the most common. The other example is a [2 + 2] cycloaddition.
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.
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