A note about what you should see above: We are interested in molecules, their
shapes, properties and reactions. The Applet above will display and animate the
molecule on this page, and various others scattered throughout
the documents describing our work. For the applet controls, press the right mouse button (or ctrl-click with MacOS).
The example shows the key transition state in the catalytic polymerisation
of lactide to polylactide, a new generation of bio-sustainable polymer not dependent on oil. This particular
Magnesium-based catalyst produces heterotactic polymer, where the configuration of the
lactide units alternates in the polymer chain, in the manner RR, SS, RR, SS, etc.
Understanding why this happens was achieved using the above model, derived from
accurate quantum mechanical (density functional) calculations of the reaction mechanism. This was published as:
Gibson, Vernon C.; Marshall, Edward L.; Rzepa, Henry S.
"
A computational study on the ring-opening polymerization of
lactide initiated by β-diketiminate metal alkoxides: The
origin of heterotactic stereocontrol", J. Am. Chem.
Soc., 2005, 127, 6048-6051. DOI:
10.1021/ja043819b.