Editing Isolobal principle (section)

==Extensions of the analogy==
The isolobal analogy has applications beyond simple octahedral complexes. It can be used with a variety of ligands, charged species and non-octahedral complexes.<ref name=Miessler>{{cite book|last1=Miessler |first1=G. L.|last2=Tarr |first2=D. A.|edition=3rd|publisher=Pearson Education|title=Inorganic Chemistry|year=2008}}</ref>

===Isoelectronic fragments===
The isolobal analogy can also be used with isoelectronic fragments having the same coordination number, which allows charged species to be considered. For example, Re(CO)<sub>5</sub> is isolobal with CH<sub>3</sub> and therefore, [Ru(CO)<sub>5</sub>]<sup>+</sup> and [Mo(CO)<sub>5</sub>]<sup>−</sup> are also isolobal with CH<sub>3</sub>. Any 17-electron metal complex would be isolobal in this example.

In a similar sense, the addition or removal of electrons from two isolobal fragments results in two new isolobal fragments. Since Re(CO)<sub>5</sub> is isolobal with CH<sub>3</sub>, [Re(CO)<sub>5</sub>]<sup>+</sup> is isolobal with {{chem|CH|3|+}}.<ref name=DMA>{{cite book|last1=Douglas |first1=B.|last2=McDaniel |first2=D.|last3=Alexander |first3=J.|edition=3rd|publisher=Wiley & Sons|title=Concepts and Models of Inorganic Chemistry|year=1994}}</ref>

===Non-octahedral complexes===

{|style="float: left;" class=wikitable border="1"
|+Figure 7: Isolobal relationship between octahedral and square planar complexes.
!Octahedral<br>ML<sub>''n''</sub>
!Square-planar<br>ML<sub>''n''−2</sub>
|-
|d<sup>6</sup>: Mo(CO)<sub>5</sub>
|d<sup>8</sup>: [PdCl<sub>3</sub>]<sup>−</sup>
|-
|d<sup>8</sup>: Os(CO)<sub>4</sub>
|d<sup>10</sup>: Ni(PR<sub>3</sub>)<sub>2</sub>
|}

[[Image:Isolobal Figure8.tif|thumb|250px|right|'''Figure 8:''' Examples of non-basic shapes in the isolobal analogy.]] 
The analogy applies to other shapes besides tetrahedral and octahedral geometries. The derivations used in octahedral geometry are valid for most other geometries. The exception is square-planar because [[square-planar complex]]es typically abide by the 16-electron rule. Assuming ligands act as two-electron donors the metal center in square-planar molecules is d<sup>8</sup>. To relate an octahedral fragment, ML<sub>''n''</sub>, where M has a d<sup>''x''</sup> electron configuration to a square planar analogous fragment, the formula ML<sub>''n''−2</sub> where M has a d<sup>''x''+2</sup> electron configuration should be followed.

Further examples of the isolobal analogy in various shapes and forms are shown in figure 8.
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