Polymerisation of Acrylates Catalysed by Methylaluminoxane Activated Ditertiary Phosphine Complexes of Iron and Cobalt Dichlorides

Diphosphane complexes of iron(II) are active catalysts for the polymerisation of methyl acrylate (MA) monomers in the presence of methylaluminoxane (MAO). High molar mass atactic MA polymers ($\overline M _{\rm n}$ ∼ 200 kg/mol) were obtained under mild conditions with relatively narrow polydispersities (PDI ∼ 2). Polymerisation activity and polymer molar masses are strongly dependent on the ligand frame. The polymerisation requires the coordination of MA to a vacant coordination site at the metal centre, and processes with chain‐transfer to aluminium. Cobalt analogues proved to be less efficient catalysts, giving activities in the range of 50–250 kg/mol · h instead of 200–450 kg/mol · h for the iron complexes. MAO activated FeCl2 and CoCl2 salts also perform the polymerisation of MA with low activity. Ditertiary phosphine complex of iron(II) chloride as methyl acrylate polymerisation catalyst.