is shown for a zirconium metallocene.
Water reacts with triethylaluminium to form a new catalyst, methylalumoxane
of Metallocene Catalysis
|The positive ion is stabilised by sharing
electrons from a C-H bond.
|In this form it catalyses polymerisation
|The positively charged zirconium
attracts ethene through the electrons of the double bond
|To see the process in action click
for an animation
|The next ethene approaches from the other
side where there is space
|Movement of electrons continues as the electron
pair of the double bond now form a new bond with zirconium, and
the active site becomes vacant again for further reaction.
|New bonds start to form as the double bond
breaks. The arrows show the movement of electrons to give the transition
state on the right.