Question

Geometrical isomerism is not observed in complexes of coordination number 4 with tetrahedral geometry.
State True or False.
A.True
B.False

Answer 1

The definition of tetrahedral is that the 4 parts are equidistant and of equal angles from the others. Isomerism is changing the molecule based on the ligand positions when rotated or exchanged. However, since the ligands are all the same in respect to every other, their relative positions do not really matter. It can always simply be rotated to match the original.

Complete step by step answer:
Geometric isomers are two or more compounds with the same number and types of atoms, and bonds, but which have different geometries for the atoms.
The most likely example of geometric isomerism you will meet at an introductory level is but-2-ene. In one case, the $C{H_3}$ groups are on opposite sides of the double bond, and in the other case they are on the same side. Geometric isomers can only occur where there is restricted rotation about a bond.
Tetrahedral complexes do not show geometrical isomerism because the relative positions of the unidentate ligands attached to the central metal atom are some with respect to each other.
Tetrahedral complexes do not show geometrical isomerism because of the following two reasons:
because all the four ligands are adjacent or equidistant to one another in the tetrahedral complex.
because the relative positions of donor atoms of ligands attached to the central atom are the same with respect to each other.

Therefore, the correct answer is option (B).

Note: We should note that geometrical isomerism requires the possibility of a different structure where the distance between any two particular groups can be changed as compared to the first structure.