Question

The complex can be formally formed from $K_2\left[PtC{l}_4\right]$ by which one of the following sequences of substitution of the chloride ions?

• A. $Py,B{r}^{-},N{H}_3$
• B. $B{r}^{-},Py,N{H}_3$
• C. $B{r}^{-},N{H}_3,Py$
• D. $N{H}_3,B{r}^{-},Py$

Answer 1

The correct option is D $N{H}_3,B{r}^{-},Py$

The correct sequence of substitution of the chloride ions for the formation of the complex from $K_2\left[PtC{l}_4\right]$ is $N{H}_3,B{r}^{-},Py$.
This will form the complex $\left[PtCl\right(N{H}_2\left)BrPy\right]$.
This is a ligand substitution reaction. The correct sequence of substitution of the chloride ions for the formation of the complex depends on the relative strength of the two metal-ligand bonds and the stability of the departing and incoming ligands.