Question

Are the following compounds primary, secondary, or tertiary?

Short answer

The categories of the given compounds are:

1. Tertiary alcohol.
2. Primary amine.
3. Secondary alcohol.
4. Secondary amine.

Step-by-step solution

Definition of primary, secondary, and tertiary amines

Primary amines are amines in which the main atom is 1°, which means that there is only one group attached to the compound and the others are hydrogens attached to the group.

Example: NH₃.

Secondary amines are amines in which an amine (2°) has two groups attached to the main atom and the remaining atoms are hydrogen atoms.

Example: isobutyl group, -CH(CH₃)₂.

Tertiary amines are amines in (3°) which an amine has three groups attached to the main atom.

Example: tert butyl group -C(CH₃)₃.

Explanation of inductive effect

An inductive effect is designated as the change in the electron density throughout a bond for having a particular electron rich or deficient group, which creates a permanent dipole moment.

There are two types of inductive effects:

1. Positive inductive effect (+I): The attached group pushes back the electrons in the bonds.
2. Negative inductive effect (-I): The attached Group pulls the electrons towards it.

Classification between the compounds

Compound a is a tertiary halide as there are 3 methyl (-CH₃) groups attached to the central carbon atom. The structure gets stabilized due to the +I effect of 3 methyl groups.

Compound b is a primary because there is only 1 group attached to the N atom and the other 2 are H atoms. However, the group attached to the NH₂ is a tertiary group, but the amine is primary.

Compound c is a secondary alcohol as it has 2 groups attached to the central C atom, both of which shows a +I effect.

Compound d is a secondary amine as two different groups are attached to the N atom and the 3^rd one is an H atom.