Unit 5: Molecular Orbitals
Molecular Orbital Theory
Molecular Orbital (MO) Theory is a sophisticated bonding model. It is generally considered to be more powerful than Lewis and Valence Bond Theories for predicting molecular properties; however, this power comes at the price of complexity. In its full development, MO Theory requires complex mathematics, though the ideas behind it are simple. Atomic orbitals (AOs) that are localized on individual atoms combine to make molecular orbitals (MOs) that are distributed over the molecule. The simplest example is the molecule dihydrogen (H 2 ), in which two independent hydrogen 1s orbitals combine to form the \(\sigma\) bonding MO and the \(\sigma\) antibonding MO of the dihydrogen molecule (see figure). The MO’s are also called Linear Combinations of Atomic Orbitals (LCAO).
-
- 5.3: Diatomic MO Diagrams
-
- 5.3.1: Homonuclear Diatomic Molecules
- 5.3.1.1: Molecular Orbitals
- 5.3.1.2: Orbital Mixing
- 5.3.1.3: Diatomic Molecules of the First and Second Periods
- 5.3.1.4: Photoelectron Spectroscopy
- 5.3.2: Heteronuclear Diatomic Molecules
- 5.3.2.1: Orbital ionization energies
- 5.3.2.2: Polar bonds
- 5.3.2.3: Ionic Compounds and Molecular Orbitals