Question

Write the structure of the geometrical isomer of the following complex:

[Pd(NO₂)₂(NH₃)₂]

Write the structure of cis- and trans-isomers of the following complex: 

[Pd(NH₃)₂(NO₂)₂]

Answer 1

1. In the cis isomer, the two NO₂ ligands are adjacent to each other (at a 90° angle in the square planar arrangement). The two NH₃ ligands are also adjacent to each other, occupying the other two positions.
   \[\begin{array}{cc}
   \phantom{.}\ce{H3N}\phantom{...}\ce{NO2}\\
   \backslash\phantom{..}/\\
   \ce{Pd}\\
   /\phantom{..}\backslash\\
   \phantom{.}\ce{H3N}\phantom{...}\ce{NO2}\phantom{.}\\
   \ce{cis-isomer}
   \end{array}\]
2. In the trans isomer, the two NO₂ ligands are opposite to each other (at a 180° angle in the square planar arrangement). The two NH₃ ligands occupy the remaining two positions, also opposite each other.
   \[\begin{array}{cc}
   \phantom{.}\ce{H3N}\phantom{...}\ce{NO2}\\
   \backslash\phantom{..}/\\
   \ce{Pd}\\
   /\phantom{..}\backslash\\
   \phantom{.}\ce{O2N}\phantom{...}\ce{NH3}\phantom{.}\\
   \ce{trans-isomer}
   \end{array}\]