Molecular Structure and Bonding

 

p Electrons in Conjugated Organic Molecules

 

Lecture 4     Synopsis

 

p electron atomic charge and p electron bond order

 

The Woodward-Hoffmann rules and cycloaddition

      

Learning Objectives:

 

·      To learn the concept of p electron atomic charge and how to calculate it.

 

·      To learn the concept of p electron bond order and how to calculate it.

 

·      To learn about the principles of orbital symmetry conservation in chemical reactions.

 

·      To apply this to the cycloaddition of 2 ethenes to form cyclobutane.

 

·      To learn how to assign symmetries to the MOs of reactants and products and to draw a correlation diagram which relates them.

 

Ian Fleming “Frontier Orbitals and Organic Chemical Reaction”,

Chapter 4.

R.B. Woodward and R Hoffmann “Conservation of Orbital Symmetry”.

pages 1-64

 

 

Calculating p-electron atomic charges