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

Options

A. `NH_(3)gtCN^(-)gtBr^(-)gtC_(6)H_(5)^(-)`
B. `CN^(-)gtC_(6)H_(5)^(-)gtBr^(-)gtNH_(3)`
C. `Br^(-)gtCN^(-)gtNH_(3)gtC_(6)H_(5)^(-)`
D. `CN^(-)gtBr^(-)gtC_(6)H_(5)^(-)gtNH_(3)`

Answer

B

Explanation

Trans effect is the effect of a coordinated group upon the rate of substitution at the position trans to itself in a square or octahedral complex. As the rate of substitution of the trans ligand increases, the intensity of trans effect also increases. Thus, correct order is,
`CN^(-)gtC_(6)H_(5)^(-) gtBr^(-)gtNH_(3)`