Why is sp2 planar

Advanced Concepts of Chemical Bonding. Search for:. Learning Objective Recognize the role of sp 2 hybridized atoms in sigma and pi bonding. In an ethene molecule, a double bond between carbons forms with one sigma and one pi bond. Show Sources Boundless vets and curates high-quality, openly licensed content from around the Internet.

Licenses and Attributions. Configurational Stereoisomers of Alkenes The carbon-carbon double bond is formed between two sp2 hybridized carbons, and consists of two occupied molecular orbitals, a sigma orbital and a pi orbital. Other Aromatic Compounds A planar or near planar cycle of sp2 hybridized atoms, the p-orbitals of which are oriented parallel to each other. Cyclooctatetraene fails both requirements, although it has a ring of sp2 hybridized atoms.

By hybridizing this heteroatom to a sp2 state, a p-orbital occupied by a pair of electrons and oriented parallel to the carbon p-orbitals is created. Allotropes of Carbon It is an allotrope of carbon whose structure is a single planar sheet of sp2 bonded carbon atoms that are densely packed in a honeycomb crystal lattice. The properties of amorphous carbon depend on the ratio of sp2 to sp3 hybridized bonds present in the material.

In other words, you only have to count the number of bonds or lone pairs of electrons around a central atom to determine its hybridization. What are the hybridizations for each of the central atoms in the following molecule? See Answer. As you can see from the example above, assigning the hybridization to each central atom is easy as long as you can count to 6.

What is really cool about the hybridization is that each hybridization corresponds to an electron pair geometry. So if you know the hybridization of an atom you automatically know its EPG.

For s and sp hybridized central atoms the only possible molecular geometry is linear, correspondingly the only possible shape is also linear:. For sp2 hybridized central atoms the only possible molecular geometry is trigonal planar. If all the bonds are in place the shape is also trigonal planar. If there are only two bonds and one lone pair of electrons holding the place where a bond would be then the shape becomes bent. For sp3 hybridized central atoms the only possible molecular geometry is tetrahedral.

If all the bonds are in place the shape is also tetrahedral. If there are only three bonds and one lone pair of electrons holding the place where a bond would be then the shape becomes trigonal pyramidal, 2 bonds and 2 lone pairs the shape is bent. For sp3d hybridized central atoms the only possible molecular geometry is trigonal bipyramidal. If all the bonds are in place the shape is also trigonal bipyramidal.

If there are only four bonds and one lone pair of electrons holding the place where a bond would be then the shape becomes see-saw, 3 bonds and 2 lone pairs the shape is T-shaped, any fewer bonds the shape is then linear.

For sp 3 d 2 hybridized central atoms the only possible molecular geometry is Octahedral. If all the bonds are in place the shape is also Octahedral. If there are only five bonds and one lone pair of electrons holding the place where a bond would be then the shape becomes Square pyramid, 4 bonds and 2 lone pairs the shape is square planar, 3 bonds and 3 lone pairs the shape is T-shaped.