Question

The correct increasing order of trans-effect of the following species is :

• A. $B{r}^{-}>C{N}^{-}>N{H}_3>C_6{H}_5^{-}$
• B. $C{N}^{-}>B{r}^{-}>C_6{H}_5^{-}>N{H}_3$
• C. $N{H}_3>C{N}^{-}>B{r}^{-}>C_6{H}_5^{-}$
• D. $C{N}^{-}>C_6{H}_5^{-}>B{r}^{-}>C_6{H}_5^{-}$

Answer 1

The correct option is D $C{N}^{-}>C_6{H}_5^{-}>B{r}^{-}>C_6{H}_5^{-}$

Trans effect order $C{N}^{-}>C_6{H}_5^{-}>B{r}^{-}>N{H}_3$

Trans effect can be defined as the effect of a ligand towards substitution on other ligand which is trans to it. Those ligands which are trans directing, that means, which prefer a trans structure, mostly in Square planar complexes. The intensity of the trans-effect as measured by the increase in rate of substitution of the trans ligand.