配体较弱的配体之间的差异

Key Difference – Strong LigandvsWeak Ligand

A ligand is anatom，离子或捐赠或共享其中两个的分子electronsthrough a协调共价键带有中央原子或离子。配体的概念在协调化学下进行了讨论。配体是与金属离子形成复合物的化学物种。因此，它们也被称为complexing agents。配体可以根据配体的牙齿性是单齿，二齿，三叉戟等。牙齿是配体中存在的供体群体的数量。单态意味着配体只有一个供体组。双齿意味着每个配体分子有两个供体组。基于分类的两种主要类型的配体crystal field theory;较强的配体（或强场配体）和弱配体（或弱田配体）。这关键区别在较强的配体和弱配体之间the splitting of orbitals after binding to a strong field ligand causes a higher difference between the higher and lower energy level orbitals whereas the splitting of orbitals after binding to a weak field ligand causes a lower difference between the higher and lower energy level orbitals.

CONTENTS

1。概述和关键差异
2。What is Crystal Field theory
3。什么是强壮的配体
4.什么是弱配体
5.Side by Side Comparison – Strong Ligand vs Weak Ligand in Tabular Form
6.Summary

What is Crystal Field Theory?

Crystals field theory can be described as a model that is designed to explain the breaking of degeneracies (electron shells of equal energy) of electronorbitals(usually d or f orbitals) due to the static electric field produced by a surrounding阴离子或阴离子（或配体）。该理论通常用于证明过渡金属离子复合物的行为。该理论可以解释磁性特性，配位络合物的颜色，水合焓等。

理论：

金属离子与配体之间的相互作用是金属离子之间带有正电荷的吸引力和配体未配对电子的负电荷。该理论主要基于在五个退化的电子轨道中发生的变化（金属原子具有五个d轨道）。当配体接近金属离子时，未配对的电子比金属离子的其他D轨道更接近某些D轨道。这会导致退化。而且，D轨道中的电子驱除了配体的电子（因为两者都是负电荷）。因此，与其他D轨道相比，接近配体的D轨道具有高能量。这导致基于能量将D轨道分解为高能轨道和低能轨道。

Some factors affecting this splitting are; nature of the metal ion, the oxidation state of metal ion, the arrangement of ligands around the central metal ion and the nature of ligands. After the splitting of these d orbitals based on energy, the difference between the high and low energy d orbitals is known as a crystal-field splitting parameter (∆_十月for octahedral complexes).

分裂模式：由于有五个d轨道，因此分裂的比例为2：3。在八面体配合物中，两个轨道处于高能水平（统称为“”eg’), and three orbitals are in the lower energy level (collectively known ast2g）。在四面体复合物中，相反的发生。三个轨道处于较高的能级，两个轨道处于较低的能级。

什么是强壮的配体?

强壮的配体或强场配体是一种配体，可以导致较高的晶体场分裂。This means, the binding of a strong field ligand causes a higher difference between the higher and lower energy level orbitals. Examples include CN^-(cyanide ligands), NO₂^-（硝基配体）和CO（羰基配体）。

In the formation of complexes with these ligands, at first, the lower energy orbitals (t2g) are completely filled with electrons before filling to any other high energy level orbitals (eg). The complexes formed in this way are called “low spin complexes”.

什么是弱配体？

配体弱或弱场配体是一种配体，可以导致较低的晶体场分裂。这意味着弱场配体的结合会导致较高和较低能级轨道之间的差异较低。

In this case, since the low difference between the two orbital levels causes repulsions between electrons in those energy levels, the higher energy orbitals can be easily filled with electrons when compared to that in low energy orbitals. The complexes formed with these ligands are called “high spin complexes”. Examples of weak field ligands include I^-（碘化物配体），BR^-（溴化物配体），等等。

What is the Difference Between Strong Ligand and Weak Ligand?

强壮的配体与弱配体
强壮的配体或强场配体是一种配体，可以导致较高的晶体场分裂。	配体弱或弱场配体是一种配体，可以导致较低的晶体场分裂。
理论
这splitting after binding a strong field ligand causes a higher difference between the higher and lower energy level orbitals.	结合弱场配体后的轨道分裂会导致较高和较低能级轨道之间的差异较低。
Category
这complexes formed with strong field ligands are called “low spin complexes”.	由弱场配体形成的复合物称为“高自旋配合物”。

概括 -Strong LigandvsWeak Ligand

强壮的配体和弱配体是阴离子或分子，这些阴离子或分子将金属离子的D轨道分解为两个能级。强配体和弱配体之间的差异是，结合强场配体后的分裂会导致较高和较低的能级轨道之间的较高差异，而结合弱场配体后轨道的分裂会导致较高和较低的差异较低的差异能级轨道。

参考：

1。Helmenstine, Anne Marie, D. “Ligand Definition.” ThoughtCo, Feb. 11, 2017.在这里可用
2。“Ligands.” Chemistry LibreTexts, Libretexts, 19 Jan. 2018.在这里可用
3。这Editors of Encyclopædia Britannica. “Ligand.” Encyclopædia Britannica, Encyclopædia Britannica, inc., 12 Aug. 2010.在这里可用

图片提供：

1.英语Wikipedia用户Yana，'conthechedral Crystal-field分裂(CC BY-SA 3.0)通过下议院维基梅迪亚
2.’cft-low旋转拆分图 - 向量'By nnfopt，（公共领域）通过下议院维基梅迪亚
3.’cft-ft-thigh旋转拆分图 - 矢量'Bynfopt，由Yana创建的参考图像 - 自己的作品（公共领域）通过下议院维基梅迪亚