Question

What is a non-conjugated ketone and what is a conjugated ketone?

Answer 1

Hint : We know that the non-aromatic or aromatic compounds can be checked by certain rules, if it follows then, aromatic and if not then, not aromatic. Aromaticity is a special property which is seen in organic compounds of ring-shaped, flat structures with a ring of conjugated systems that gives increased stability.

Complete Step By Step Answer:
An aromatic compound contains a set of covalent bonds with specific characteristics a delocalized conjugated system of electrons, which is an arrangement of alternating single and double bonds. It should be a coplanar structure having all the atoms in the same plane. It should follow Huckel’s rule, a number of delocalized electrons. In a conjugated system, electrons are delocalized with the alternate single and double bond. Lone pairs can also be part of the system.
Conjugated ketone has a $C=C$ unit attached directly to carbon of the carbonyl group. While in Non-conjugated ketones the carbonyl group don't contact with any $C=C$ unit $C{{H}_{2}}=CH-C\left( O \right)-C{{H}_{3~}}$ is a simple conjugate ketone (the Carbon atom connected to the Carbon atom of the carbonyl group forms a double bond to another carbon atom while $C{{H}_{2}}=CH-C{{H}_{2}}-C\left( O \right)-C{{H}_{3}}$ would be non-conjugate because the Carbon atoms forming the double bond don't contact the carbonyl group directly.

Note :
Remember that the compound’s’ does not seem to be aromatic by its structure because the ring has electrons, which does not satisfy Huckel’s rule. But on resonance, with other atoms, a resonating structure is formed which is aromatic. So, do not judge Aromaticity by just looking at the compound, it can be aromatic in one form or another.