Abstract
The phosphine-substituted aryl diimine cobalt catalyst, (Ph2PPrADI)Co, has been found to mediate the dehydrocoupling of diamines or polyamines to poly(methylhydrosiloxane) (PMHS) to generate hydrogen and crosslinked solids in an atom-efficient fashion. The resulting siloxane diamine and siloxane polyamine networks persist in the presence of air or water at room temperature and can tolerate temperatures of up to 1600 °C. Upon lowering the catalyst loading to 0.01 mol %, (Ph2PPrADI)Co was found to catalyze the dehydrocoupling of 1,3-propanediamine and PMHS (m = 35) to generate a siloxane diamine foam with a turnover frequency of 157 s-1 relative to diamine consumption, the highest activity ever reported for Si-N dehydrocoupling. Furthermore, upon systematically reducing the number of potential branch points, the (Ph2PPrADI)Co-catalyzed dehydrocoupling of diamines with hydride-terminated poly(dimethylsiloxane) (PDMS) was found to yield linear siloxane diamine polymers with molecular weights of up to 47,300 g/mol.
Original language | English (US) |
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Pages (from-to) | 11172-11180 |
Number of pages | 9 |
Journal | ACS Sustainable Chemistry and Engineering |
Volume | 11 |
Issue number | 30 |
DOIs | |
State | Published - Jul 31 2023 |
Keywords
- atom economy
- catalysis
- copolymers
- earth-abundant metals
- less hazardous synthesis
- main group elements
- waste prevention
ASJC Scopus subject areas
- General Chemistry
- Environmental Chemistry
- General Chemical Engineering
- Renewable Energy, Sustainability and the Environment