CHEM321 FILE 16 VALENCE BOND & HYBDIDIZATION

CHEM321 FILE 16 VALENCE BOND & HYBDIDIZATION -...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
VALENCE BOND THEORY Construction of “Hybrid Orbitals” Melvyn R. Churchill 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
VALENCE-BOND THEORY A very simple theory Explains many things Assumes a set of localized two-electron two- center bonds Very convenient – but is too simple It is not the best model. Electrons are not in fixed locations – M.O. Theory is better. For example - Photoelectron spectroscopy shows C-H bonds of CH 4 are in two different 1 2
Background image of page 2
Covalent bonds are formed when adjacent atoms share a pair of electrons. Only occurs when orbitals of appropriate symmetry on the two atoms overlap H = 1s 1 Cl = [Ne]3s 2 3p 5 + + + + + + + + - - -
Background image of page 3

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

View Full DocumentRight Arrow Icon
Overlap and Bonding Increased overlap brings the electrons and nuclei closer together & decreases electron- electron repulsion. If atoms get too close, inter-nuclear repulsion quickly raises the energy. Observed bond length Lowest energy for: [(e - -nuclei attractions) – (e - -e - & nucleus-nucleus repulsions)]
Background image of page 4
H ow can observed molecular geometries arise from familiar atomic orbitals? Valence Bond Theory explains both bonding and geometry. Hydrogenic orbitals are “mixed together” ( hybridized ) to form new orbitals - hybrid orbitals . + + + + -
Background image of page 5

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

View Full DocumentRight Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 29

CHEM321 FILE 16 VALENCE BOND & HYBDIDIZATION -...

This preview shows document pages 1 - 6. Sign up to view the full document.

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