Note: In the following questions a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: Complexes of MX6 and MX5L type (X and L are unidentate) do not show geometrical isomerism.
Reason: Geometrical isomerism is not shown by complexes of coordination number 6.
Assertion and reason both are true, but the reason is not the correct explanation of assertion.
Soln.: In the case of complexes type of MX6 and MX5L, plane of symmetry is always present as there is, only one or two types of ligands present. And the necessary condition for showing geometrical isomerism is that the complex must be of MX4B2 or [M (AB)2X2] type.
the plane of symmetry is aligned to the plane of any M-X.
the plane of symmetry is aligned to the plane of L-M-X.