In anthracene, what type of hybrid orbitals are utilized by the carbon atoms in the aromatic rings?

• A. $sp{2}^{}$ hybrid orbitals
• B. Unhybridized $p$ orbitals only
• C. $sp$ hybrid orbitals
• D. $sp{3}^{}$ hybrid orbitals

Answer: (A)

Verified step by step guidance

1. Recall that anthracene is a polycyclic aromatic hydrocarbon composed of fused benzene rings, where each carbon atom participates in the aromatic system.
2. Understand that in aromatic systems, each carbon atom typically forms three sigma bonds: two with adjacent carbons and one with a hydrogen atom (or substituent), requiring three hybrid orbitals.
3. Recognize that to form these three sigma bonds, carbon atoms use \(s p^{2}\) hybrid orbitals, which are formed by mixing one s orbital and two p orbitals.
4. Note that the remaining unhybridized p orbital on each carbon atom is oriented perpendicular to the plane of the ring and overlaps with neighboring p orbitals to form the delocalized pi system characteristic of aromaticity.
5. Conclude that the carbon atoms in anthracene utilize \(s p^{2}\) hybrid orbitals for sigma bonding and have unhybridized p orbitals for the pi bonding network.