Radical orbital switching
- Summary
- pH or electric field switchable control agents for free radical polymerisations, effective at room temperature and selective for a wide range of monomers.
- Technology Benefits
- •
Increased scope of free radical polymerisation
•
Reduced costs of manufacture due to lower reaction temperatures
•
Potential for control of polymerisation
•
No need for metal catalysts or volatile compounds
- Technology Application
- The new technique pioneered at ANU has potential to extend free radical polymerisation to reactions requiring temperatures and conditions in which existing techniques cannot be used, and to enable new methods of control in polymerisation.
- Detailed Technology Description
- This technology enables one to design alkoxyamines containing remote acidic groups that are stable to homolysis when the acidic group is protonated but readily undergo reversible homolysis to produce nitroxides and carbon centred radicals upon deprotonation of the acidic group, due to the enhanced stability of the nitroxide radical. The re-protonation of the nitroxide reverses the effect and stabilizes the alkoxyamine. In standard nitroxide mediated polymerization (NMP), high temperatures (typically > 100°C) are used to drive the homolysis reaction such that sufficient radicals are released to catalyse a controlled radical polymerization process. We can now design nitroxides where a pH switch can be used, which not only allows NMP to be carried out at much lower temperatures (e.g. 25-60°C), but also makes it feasible for such alkoxyamines to be used as radical sources in natural product synthesis. Because the stabilization effect can also be triggered by an electric field, one can also envisage tagging the alkoxyamines onto a solid support (e.g. graphene or silicon using known methods) and using an electric field to trigger the reversible release of the carbon-centred radical leaving group for polymerization or other chemical reactions.
- Type of Cooperation
- Licensing/ commercial development
- Application Date
- 06/02/2014 00:00:00
- Application No.
- WO2014121327
- Classes
- C07B 61/00 • C07D 207/46 • C07D 209/44 • C07D 211/94 • C07F 9/547 • C07F 11/00
- Others
- AU20130900371 [2013-02-06] • AU20130900373 [2013-02-06]
- Country/Region
- Australia
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