Rep:Gcw114

Transition States and Reactivity

Introduction

For a chemical reaction,the reaction pathway diagram can be drawn in Figure 1 to show the reaction coordinate as the reactant is transformed into product. The transition state is the highest energy structure with partial bond in the reaction coordinate.

Exercise 1: Reaction of Butadiene with Ethylene

HOMO and LUMO

Species	HOMO	LUMO
s-cis butadiene	s-cis butadiene mo 6; mo nodots nomesh fill translucent; mo titleformat ""	Column 3, Row 2
ethene	Column 2, Row 3	Column 3, Row 3

	Species
	Transition state
Molecular Orbital	Bonding	Symmetry
LUMO +1	Column 2, Row 3	Column 3, Row 3
LUMO	Column 2, Row 4	Column 3, Row 4
HUMO	Column 2, Row 3	Column 3, Row 3
HUMO-1	Column 2, Row 3	Column 3, Row 3