Ch400Ch7LN5 - Valence Bond Theory and Molecular Orbital...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Valence Bond Theory and Molecular Orbital Theory, Continued Molecular Orbital Theory • Some aspects of bonding are not explained by Lewis structures, VSEPR theory, or hybridization. • For example: • Why does O 2 interact with a magnetic field? • Why are some molecules colored? • What is the best way to describe delocalization of π electrons? • For these molecules, we use molecular orbital (MO) theory . • Just as electrons in atoms are found in atomic orbitals, electrons in molecules are found in molecular orbitals (MO’s) . • Molecular orbitals: • Some characteristics are similar to those of atomic orbitals: • Each contains a maximum of two electrons with opposite spins. • Each has a definite energy. • Electron density distribution can be visualized with contour diagrams. • However, unlike atomic orbitals, molecular orbitals are associated with an entire molecule . The Hydrogen Molecule • When two AO’s overlap, two MOs form. • Therefore, 1 s (H) + 1 s (H) must result in two MOs for H 2 : • One has electron density between the nuclei ( bonding MO ). • Here the 2 AO’s add together to form a bonding MO. • One has the greatest electron density on opposite sides of the nuclei with little electron density between the nuclei ( antibonding MO ). • Here the 2 AO’s subtract from each other to form an antibonding MO. • Sigma ( σ ) MOs have electron density in both molecular orbitals centered about the internuclear axis. • The σ bonding MO is lower in energy than the σ ∗ (antibonding) MO. • The energy level diagram or MO diagram shows the energies of the orbitals in a molecule....
View Full Document

This note was uploaded on 06/25/2008 for the course CHEM 400-401 taught by Professor Dr.samples during the Fall '06 term at American River.

Page1 / 4

Ch400Ch7LN5 - Valence Bond Theory and Molecular Orbital...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online