Immobilization of bis(imino)pyridyliron(II) complexes on silica

The well-known catalyst precursor 2,6-bis[1-((2,6-diisopropylphenyl)imino)ethyl]pyridine (1) is functionalized by various alkenyl groups to yield the corresponding alkenyl-functionalized 2,6-bis[1-((2,6-diisopropylphenyl)imino)ethyl]pyridine ligand. Reaction of these novel functionalized bis(imino)pyridyl ligands with iron(II) chloride results in the formation of precatalysts 5-7, which possess different spacer moieties. The possibility of self-immobilization has been investigated with respect to the chain length of the alkenyl moiety. Additionally, experiments to heterogenize these functionalized iron(II) complexes on modified silica via hydrosilation are presented (8-10). The immobilization has been studied by IR, and the resulting polymers have been characterized by GPC and static light scattering.