JEE Main20209 Jan 2020Evening ShiftChemistryAminesActual
The decreasing order of basicity of the following amines is:
Options
- AI > I I I > I V > I I
- BI I I > I > I I > I V
- CI I > I I I > I V > I
- DI I I > I I > I > I V
Correct answer
D. I I I > I I > I > I V
Step-by-step solution
Basic strength depends upon availability of lone pairs. Greater the resonance of lone pairs lesser the basic strength. In ( II )   and   ( III ) lone pair is localised. ( III ) is more basic due to + I effect of carbon chain whereas in II , negative mesomeric effect is operating. In ( I )   and   ( IV ) lone pair is delocalised, so their basic strength is less that former two amines. If ( IV ) donates its lone pair then its aromaticity will get lost therefore, its basic strength is less than tha