Question

In which the following inversion is not possible?
A.\[C{H_3}C{H_2} - N{H_2}\]
B.Propan-2-amine
C.

D.

Answer 1

Hint: There is a formation of product with respect to the molecular configuration by the spatial rearrangement of a group of atoms or atoms which is present in a dissymmetric molecule. And the product will be a mirror image of that original compound. During inversion of an atom, its relative configuration should be changed. And here the configuration may change cis to Trans and vice versa.

Complete answer:
In this case, the amine group present in the ethyl amine will show the inversion and there is a formation of methyl amine and ethyl amine. Hence, option (A) is incorrect.
The propan-2-amine is also known as isopropyl amine. And the nitrogen inversion does not take place in isopropyl alcohol. Because, the nitrogen inversion happens only when the R group is linked with nitrogen should be unique. Then the compound should be a chiral compound.
But in the case of propan-2-amine, all the atoms attached with nitrogen are the same. Therefore, inversion is not possible in the case of propan-2-amine. Hence, option (B) is correct.
In this compound all the groups are unique and the inversion occurs. Hence, option (C) is incorrect.
Here, the nitrogen is attached with four different groups and the inversion is possible in this compound. Hence, the option (D) is incorrect.

Note:
Among these given compounds, the inversion is not possible in the case of propan-2-amine. Because, the inversion of nitrogen depends on the groups attached to the nitrogen and all the groups should be unique for the inversion of this compound. But in the case of propan-2-amine, all the groups attached with nitrogen are methylene groups which are the same. Hence, it will not undergo the inversion.