Question

Benzyne is:
A. aromatic
B. non- aromatic
C. antiaromatic
D. all of the above

Answer 1

Hint:For a compound to be aromatic it should be cyclic in structure, the compound should obey Huckel’s rule which means it should have (4n+2) pi number of electrons and should be flat. If the compound does not obey these rules then it is a non-aromatic compound.

Complete step by step answer:
Benzyne is the dehydrogenated form of benzene where two hydrogen atoms are removed from the benzene. Benzyne is a chemical compound having a molecular formula $C_6{H}_4$. The IUPAC name is cyclohexa-1,3-dien-5-yne.
Benzyne is a type of aryne where –yne stands for a triple bond. The triple bond present in the ring is non-linear because of the restriction of the six-membered ring. Benzyne is a highly reactive compound because of the strain caused by the triple bond present in the ring.
The benzyne strain energy is 50 kcal/mol greater than the strain of cyclopropane that is 28 kcal/mol and slightly has less strain than cyclopropane whose value is 54 kcal/mol.
The structure of the benzyne is shown below.

In benzyne, the triple bond is formed by the overlapping of two $s{p}^2$ orbitals which are adjacent to each other in the planar ring.
Benzyne is the aromatic compound as it is cyclic, planar in geometry. It has a conjugated 6$\pi$ electron system.
Therefore, the correct option is A.

Note:
In the structure of benzyne, the second p bond of the triple bond is present perpendicularly to the other p orbital thus it does not take part in overlapping with the aromatic $\pi$ system. Thus the two electrons related to the bond do not include in the conjugated system.