Arrange the following amines in the increasing order of basicity : n-Butylamine (I), sec-Butylamine (II), Isobutylamine (III), tert-Butylamine IV.
Arrange the following amines in the increasing order of basicity : n-Butylamine (I), sec-Butylamine (II), Isobutylamine (III), tert-Butylamine IV.
A. `I lt II lt III lt IV`
B. `IV lt III lt II lt I`
C. `II lt III lt I lt IV`
D. `III lt IV lt I lt II`.
1 Answers
Correct Answer - B
Steric hindrance decrease the availablity of lone pair no nitrogen atom which in turn decreases the basic character. Thus, increasing order of basic character is : `IV lt III lt II lt I`.
Here the `+I` effect of the alkyl group operates in a direction opposite to that due to steric hindrance i.e., `+I` effect of tert-butyl group is maximum thus (IV) has to be most basic while it is least for (I) which has to be least basic. However, in this case steric factors far out weights the `+I` effect of the R-group. As such the net effect is that due to steric factors