sp2 hybridization

(noun)

the 2s orbital mixes with only two of the three available 2p orbitals

Related Terms

Examples of sp2 hybridization in the following topics:

  • sp2 Hybridization

    • In order to explain the bonding, the 2s orbital and two of the 2p orbitals (called sp2 hybrids) hybridize; one empty p-orbital remains.
    • sp2 Hybridization in Ethene and the Formation of a Double Bond
    • In this case, carbon will sp2 hybridize; in sp2 hybridization, the 2s orbital mixes with only two of the three available 2p orbitals, forming a total of three sp hybrid orbitals with one p-orbital remaining.
    • The carbon atoms are sp2 hybridized.
    • Recognize the role of sp2 hybridized atoms in sigma and pi bonding.

  • Hybridization in Molecules Containing Double and Triple Bonds

    • sp2, sp hybridizations, and pi-bonding can be used to describe the chemical bonding in molecules with double and triple bonds.
    • For this molecule, carbon will sp2 hybridize.
    • In sp2 hybridization, the 2s orbital mixes with only two of the three available 2p orbitals, forming a total of 3 sp2 orbitals with one p-orbital remaining.
    • In ethylene (ethene), the two carbon atoms form a sigma bond by overlapping two sp2 orbitals; each carbon atom forms two covalent bonds with hydrogen by s–sp2 overlapping all with 120° angles.
    • In ethene, carbon sp2 hybridizes, because one π (pi) bond is required for the double bond between the carbons, and only three σ bonds form per carbon atom.

  • Stereogenic Nitrogen

    • It rapidly inverts its configuration (equilibrium arrows) by passing through a planar, sp2-hybridized transition state, leading to a mixture of interconverting R and S configurations.

  • 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.
    • It is planar, bond angles=120º, all carbon atoms in the ring are sp2 hybridized, and the pi-orbitals are occupied by 6 electrons.
    • 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.
    • The sp2 hybridized ring atoms are connected by brown bonds, the π-electron pairs and bonds that constitute the aromatic ring are colored blue.

  • Nucleophilic Addition Reactions & Reduction

    • The sp-hybrid carbon atoms of the triple-bond render alkynes more electrophilic than similarly substituted alkenes.
    • Isolated carbon double-bonds are not reduced by sodium in liquid ammonia, confirming the electronegativity difference between sp and sp2 hybridized carbons.

  • Nomenclature and Structure of Amines

    • Nitrogen atoms that are part of aromatic rings , such as pyridine, pyrrole & imidazole, have planar configurations (sp2 hybridization), and are not stereogenic centers.
    • In contrast, atropine, coniine, morphine, nicotine and quinine have stereogenic pyramidal nitrogen atoms in their structural formulas (think of the non-bonding electron pair as a fourth substituent on a sp3 hybridized nitrogen).
    • An increase in angle strain in the sp2-hybridized planar transition state is responsible for the greater stability of the pyramidal configuration.

  • Atomic and Molecular Orbitals

    • These hybrid orbitals have a specific orientation, and the four are naturally oriented in a tetrahedral fashion.
    • Click on the following link for a model of this hybridization (http://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/Jmol-11.2/hyborbtl2.htm).
    • A mixing of the 2s-orbital with two of the 2p orbitals gives three sp2 hybrid orbitals, leaving one of the p-orbitals unused.
    • Two sp2 hybridized carbon atoms are then joined together by sigma and pi-bonds (a double bond), as shown in part B.
    • Finally, in the case of carbon atoms with only two bonding partners only two hybrid orbitals are needed for the sigma bonds, and these sp hybrid orbitals are directed 180º from each other.

  • Double and Triple Covalent Bonds

    • Double and triple bonds can be explained by orbital hybridization, or the 'mixing' of atomic orbitals to form new hybrid orbitals.
    • A combination of s and p orbitals results in the formation of hybrid orbitals.
    • From the perspective of the carbon atoms, each has three sp2 hybrid orbitals and one unhybridized p orbital.
    • The three sp2 orbitals lie in a single plane at 120-degree angles.
    • A schematic of the resulting orientation in space of sp3 hybrid orbitals.

  • 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.
    • Graphite consists purely of sp2 hybridized bonds, whereas diamond consists purely of sp3 hybridized bonds.
    • Materials that are high in sp3 hybridized bonds are referred to as tetrahedral amorphous carbon (owing to the tetrahedral shape formed by sp3 hybridized bonds), or diamond-like carbon (owing to the similarity of many of its physical properties to those of diamond).