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CHEM 121 Studioby Learn4Less · UBC CHEM 121

CHEM 121 glossary

Unhybridized p orbital

A p orbital that an spsp or sp2sp^2 atom leaves out of hybridization; it sits perpendicular to the hybrid orbitals. Unhybridized p orbitals on neighbouring atoms overlap side-on to form π bonds: an sp2sp^2 atom has one, an spsp atom two and an sp3sp^3 atom none.

sp² hybrid orbitals3 sp² hybrid orbitals point away from each other in a trigonal planar arrangement, 120° apart. one unhybridized p orbital, ⊥ to the plane, remains.120°three sp² orbitals · trigonal planarone unhybridized p orbital, ⊥ to the plane, remains

An sp2sp^2 atom: three hybrids in a plane, one p orbital left perpendicular.

Example

In ethene each sp2sp^2 carbon keeps one 2p2p orbital perpendicular to the molecular plane, and the two overlap side-on to form the C=C π bond. In benzene all six of these p orbitals overlap around the ring, delocalizing 6 π electrons.

See alsoπ bond (pi bond)sp² hybrid orbitalsp hybrid orbitalConjugation