CHEM321 FILE 17 DIATOMIC MOLECULES

CHEM321 FILE 17 DIATOMIC MOLECULES - DIATOMIC MOLECULES...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
DIATOMIC MOLECULES Molecular Orbital Theory for Simple Homonuclear Diatomic Molecules Melvyn R. Churchill Version of: October 18 2010
Background image of page 1

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

View Full DocumentRight Arrow Icon
Why Molecular Orbital Theory? Valence Bond Theory (VBT) is simple but has obvious limitations, including ··· The artificial concept of “resonance” is introduced in an attempt to explain the symmetry & delocalized nature of such structures as ozone (O 3 ), sulfate (SO 4 2- ), nitrate (NO 3 - ), sulfur dioxide (SO 2 ), C 6 H 6 (benzene) & many, many others. VBT does not explain why O 2 has 2 unpaired electrons VBT does not deal with molecular spectra and excited states. Molecular Orbital Theory solves these problems –and can give rise to quantitative predictions But…. MO Theory is more complicated than VBT
Background image of page 2
Similarities Between Atomic Orbitals (AO’s) and Molecular Orbitals (MO’s) Each orbital holds a maximum of two electrons with opposite spins. Each orbital has a defined energy. We can produce contour plots for the electron-density distribution for both AO’s and MO’s Key difference: MO’s belong to the entire molecule, not to an individual atom.
Background image of page 3

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

View Full DocumentRight Arrow Icon
Molecular Orbital (MO) Theory for H 2 In MO theory, we invoke the wave nature of electrons. When waves interact constructively (same sign on the interacting orbitals), the electron density is greatest between the two nuclei and a lower-energy bonding molecular orbital is formed ( similar to a covalent bond ).
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/10/2010 for the course CHE inorganic taught by Professor Dr.charchill during the Spring '10 term at SUNY Buffalo.

Page1 / 27

CHEM321 FILE 17 DIATOMIC MOLECULES - DIATOMIC MOLECULES...

This preview shows document pages 1 - 5. Sign up to view the full document.

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