Knowt 8 - Adv. Theories of Covalent Bonding

Valence bond theory

Model describing bonding as overlap of atomic orbitals to share electrons

Sigma bond (σ bond)

Covalent bond from end-to-end overlap of atomic orbitals along the internuclear axis

Pi bond (π bond)

Covalent bond from side-by-side overlap of atomic orbitals, with electron density on opposite sides of the axis

Overlap

Coexistence of orbitals from two atoms sharing space to form a covalent bond

Hybrid orbital

Orbital created by combining atomic orbitals on a central atom for bonding

Hybridization

Model describing changes in atomic orbitals when forming covalent compounds

Sp hybrid orbital

One of two linear orbitals from combining one s and one p orbital

Sp² hybrid orbital

One of three trigonal planar orbitals from combining one s and two p orbitals

Sp³ hybrid orbital

One of four tetrahedral orbitals from combining one s and three p orbitals

Sp³d hybrid orbital

One of five trigonal bipyramidal orbitals from combining one s, three p, and one d orbital

Sp³d² hybrid orbital

One of six octahedral orbitals from combining one s, three p, and two d orbitals

Multiple bonds

Bonds consisting of one σ bond and one or two π bonds between atoms

Resonance

Phenomenon where multiple orbital alignments allow π bond placement to vary

Molecular orbital

Region of space where an electron is likely found in a molecule

Molecular orbital diagram

Visual representation of relative energy levels of molecular orbitals

Molecular orbital theory

Model describing electron behavior in molecules via combined atomic wave functions

Bonding orbital

Molecular orbital between nuclei that stabilizes the molecule

Antibonding orbital

Molecular orbital outside nuclei regions that destabilizes the molecule

Degenerate orbitals

Orbitals with the same energy

Bond order

Number of electron pairs between atoms, calculated as (bonding electrons - antibonding electrons)/2

Node

Plane where electron probability is zero, separating orbital lobes

Paramagnetism

Attraction to magnetic fields due to unpaired electrons

Diamagnetism

Repulsion from magnetic fields due to all paired electrons

Homonuclear diatomic molecule

Molecule with two identical atoms

Linear combination of atomic orbitals

Technique combining atomic orbitals to form molecular orbitals

S-p mixing

Mixing of s and p orbitals causing σ p orbitals to be less stable than π p orbitals

π bonding orbital

Molecular orbital from side-by-side overlap with density on opposite sides of the axis

π bonding orbital*

Antibonding orbital from out-of-phase side-by-side overlap with a node between nuclei

σ bonding orbital

Molecular orbital with density along the bond axis

σ bonding orbital*

Antibonding orbital from out-of-phase overlap along the axis with a node between nuclei

Bond Order Equations

Bond Order = (# Bonding e-) - (# Antibonding e-) / 2