sp2hybridiserat

Sp2hybridiserat describes a state in valence bond theory where an atom uses three sp2 hybrid orbitals formed by the mixing of one s and two p orbitals, leaving one unhybridized p orbital. These three hybrid orbitals are arranged approximately in a trigonal planar geometry with bond angles near 120 degrees. The remaining unhybridized p orbital lies perpendicular to the plane and can participate in pi bonding.

In molecules containing sp2-hybridized atoms, the three sp2 orbitals typically form sigma bonds to other atoms or to lone pairs, while the pi bond arises from the side-by-side overlap of the unhybridized p orbitals between adjacent atoms. This arrangement enables double bonds (as in alkenes) and provides a basis for conjugation in many systems.

Common examples include carbon atoms in alkenes such as ethene, where each carbon is sp2-hybridized to form three sigma bonds and one pi bond, leading to a planar molecule. Carbonyl carbons (as in formaldehyde and many aldehydes and ketones) are also sp2-hybridized, contributing to the planar C=O bond and the overall geometry. In aromatic systems like benzene, all ring carbons are sp2-hybridized, producing a delocalized pi system above and below the ring.

Limitations of the concept include its reliance on a simplifying model; in reality, electron density and bonding can be better described by molecular orbital theory, particularly in conjugated or highly strained systems. Nevertheless, sp2 hybridization remains a useful framework for understanding the geometry and bonding of many planar, double-bonded, or conjugated species.