If Ni 2 + is replaced by Pt 2 + in the complex NiCl 2 Br 2 2 - , which of the following properties are…

When${\mathrm{Ni}}^{2+}$ is replaced by${\mathrm{Pt}}^{2+}$ in the complex ${\left[{\mathrm{NiCl}}_2{\mathrm{Br}}_2\right]}^{2-}$, the following properties are expected to be changed:

A. Geometry: Since ${\mathrm{Pt}}^{2+}$ and${\mathrm{Ni}}^{2+}$ have different coordination preferences and atomic sizes, the replacement is likely to result in a change in the geometry of the complex. That is it changes to square planar.

B. Geometrical isomerism: If the replacement of ${\mathrm{Ni}}^{2+}$ with ${\mathrm{Pt}}^{2+}$ leads to a change in the ligand arrangement, it can result in the generation of cis and trans isomers.

C. Magnetic properties: ${\left[{\mathrm{PtCl}}_2{\mathrm{Br}}_2\right]}^{2-}$ is diamagnetic.

Both the complex species are optically inactive.