Question

Giving suitable examples, discuss the geometrical isomerism shown by the following type of complex:

[Ma₂b₂]^n±

Answer 1

• Geometrical isomerism in [Ma₂b₂] coordination complexes arises from the spatial arrangement of the ligands around the central metal ion.
• For a coordination compound with the formula [Ma₂b₂], where M is the central metal ion and a and b are different ligands, geometrical isomerism arises due to the possible different spatial arrangements of these ligands around the central metal ion.
• This type of isomerism is typically observed in complexes with a coordination number of 4, often exhibiting square planar or tetrahedral geometry.
• For example, the cis and trans forms of complex diamminedichloridoplatinum (II), [PtC1₂(NH₃)₂].
  Cis Isomer: Both NH₃ ligands are adjacent to each other, and both Cl⁻ ions are opposite each other.
  Trans Isomer: The NH₃ ligands are opposite to each other, and the Cl⁻ ions are adjacent to each other.