Arrange the following compounds in increasing order of their basic strength.

Options

A. `I lt II lt III lt IV`
B. `IV lt III lt II lt I`
C. `IV lt II lt I lt III`
D. `IV lt II lt III lt I`

Answer

C

Explanation

Pyrrole (IV) is least basic in the above list because lone pair of nitrogen is part of aromatic ring. Not available for donation to a Lewis acid. III is most basic because lone pair on nitrogen is not involved in any delocalisation as well as present on `sp^(3)` -N. I is more basic than II because lone pair is present on `sp^(3)`-N in pyridine while it is on `sp^(3)`-N in aniline.