Geometries of Complexes with Different Coordination Numbers

GEOMETRIES OF COMPLEXES WITH DIFFERENT COORDINATION NUMBERS 

Coordination number 2 This is a relatively uncommon coordination number and is restricted to a few cases, such as Cu(I), Ag(I), Au(I), and Hg(II) ions having d configuration. [CuCy and [Ag(NHy)2] are the representative complexes of this coordination number. 

The possible geometries for the complexes with CN = 2 are linear and angular. Linear geometry is commonly observed in such complexes. 

However, CN = 3 is also illustrated by a few true complexes such as Hgl3 and [Cu(SPMe3)] ions. These complexes exhibit trigonal planar geometry, as shown in the figure. 

Coordination number 4 This is one of the most commonly observed coordination numbers. There are two possible geometries associated with CN = 4, viz, tetrahedral and square planar. 

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