orbital hybridization

Examples of orbital 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.
  • 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.
  • This illustration shows how an s-orbital mixes with two p orbitals to form a set of three sp2 hybrid orbitals.
  • Notice again how the three atomic orbitals yield the same number of hybrid orbitals.
  • The atomic s- and p-orbitals in boron's outer shell mix to form three equivalent hybrid orbitals.

• sp3 Hybridization

  • sp3 hybrid orbitals form when a single s and three p orbitals hybridize.
  • This would indicate that one of the four bonds differs from the other three, but scientific tests have proven that all four bonds have equal length and energy; this is due to the hybridization of carbon's 2s and 2p valence orbitals.
  • In hybridization, carbon's 2s and three 2p orbitals combine into four identical orbitals, now called sp3 hybrids.
  • For example, in the ammonia molecule, the fourth of the sp3 hybrid orbitals on the nitrogen contains the two remaining outer-shell electrons, which form a non-bonding lone pair.
  • Explain the process of hybridization as it applies to the formation of sp3 hybridized atoms.

• sp Hybridization

  • In sp hybridization, the s orbital overlaps with only one p orbital.
  • When atomic orbitals hybridize, the valence electrons occupy the newly created orbitals.
  • The hybridization process involves mixing of the valence s orbital with one of the valence p orbitals to yield two equivalent sp hybrid orbitals that are oriented in a linear geometry.
  • The number of atomic orbitals combined always equals the number of hybrid orbitals formed.
  • Hybridization of an s orbital and a p orbital of the same atom produces two sp hybrid orbitals.

• Hybridization in Molecules Containing Double and Triple Bonds

  • In chemistry, hybridization is the concept of mixing atomic orbitals to form new hybrid orbitals suitable for describing bonding properties.
  • The hybrids are named for the atomic orbitals involved in the hybridization.
  • 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.
  • The sp hybridized orbitals are used to overlap with the 1s hydrogen orbitals and the other carbon atom.
  • The remaining, non-hybridized p-orbitals overlap for the double and triple pi bonds.

• 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.
  • A schematic of the resulting orientation in space of sp3 hybrid orbitals.
  • Notice that the sum of the superscripts (1 for s, and 3 for p) gives the total number of formed hybrid orbitals.

• Atomic and Molecular Orbitals

  • These hybrid orbitals have a specific orientation, and the four are naturally oriented in a tetrahedral fashion.
  • In the case of bonds between second period elements, p-orbitals or hybrid atomic orbitals having p-orbital character are used to form molecular orbitals.
  • For example, the sigma molecular orbital that serves to bond two fluorine atoms together is generated by the overlap of p-orbitals (part A below), and two sp3 hybrid orbitals of carbon may combine to give a similar sigma orbital.
  • A mixing of the 2s-orbital with two of the 2p orbitals gives three sp2 hybrid orbitals, leaving one of the p-orbitals unused.
  • 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.

• Bonding in Coordination Compounds: Valence Bond Theory

  • Finally, Linus Pauling integrated Lewis' proposal and the Heitler-London theory to give rise to two additional key concepts in valence bond theory: resonance and orbital hybridization.
  • We see the concept of orbital hybridization arise when bonding orbitals share the characteristics of several types of orbitals.
  • When we apply valence bond theory to a coordination compound, the original electrons from the d orbital of the transition metal move into non-hybridized d orbitals.
  • The electrons donated by the ligand move into hybridized orbitals of higher energy, which are then filled by electron pairs donated by the ligand.
  • Calculate the theoretical hybridization of a metal in a coordination complex based on valence bond theory

• 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.
  • Rotation of the end groups of a double bond relative to each other destroys the p-orbital overlap that creates the pi orbital or bond.

• Other Aromatic Compounds

  • A planar (or near planar) cycle of sp2 hybridized atoms, the p-orbitals of which are oriented parallel to each other.
  • These overlapping p-orbitals generate an array of π-molecular orbitals.
  • 1,3-Cyclopentadiene and 1,3,5-cycloheptatriene both fail to meet the first requirement, since one carbon atom of each ring is sp3 hybridized and has no p-orbital.
  • 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.

• Theoretical Models for Pericyclic Reactions

  • A general introduction to molecular orbitals was presented earlier.
  • A molecular orbital diagram of ethene is created by combining the twelve atomic orbitals associated with four hydrogen atoms and two sp2 hybridized carbons to give twelve molecular orbitals.
  • Six of these molecular orbitals (five sigma & one pi-orbital) are bonding, and are occupied by the twelve available valence shell electrons.
  • The π-orbital on the left has one nodal plane (colored light blue), and the π*-orbital on the right has a second nodal plane (colored yellow).
  • The symmetries of the appropriate reactant and product orbitals were matched to determine whether the transformation could proceed without a symmetry imposed conversion of bonding reactant orbitals to antibonding product orbitals.