In the proposed research of this project, two new families of homogeneous, non-cyclopentadienyl organolanthanide
catalysts of the general formula L-LnX 2 will be synthesized and evaluated with regard to their performance as
polymerization catalysts of olefins, acrylates, and lactones.
In organolanthanide chemistry, very large multidentate ligands are in general necessary to stabilize these highly
Lewis acidic, chalco- and pnictophilic lanthanide metals Ln = Y, La, Nd, Sm, Yb, Lu as monomeric chelate
complexes, and to ensure an optimized ligand sphere for the envisioned catalytic applications.
The first family of new organolanthanide catalysts will comprise L-LnX 2 metal complexes with monoanionic,
atrane-like, constrained geometry-type, tri- and tetradentate triptyceneimine ligands of tunable steric shielding due
to the number and steric bulk of the imino substituents. The second family will comprise L-LnX 2 metal complexes
with mono- or dianionic, chiral, pincer-type, tridentate bissulfoximine ligands of tunable steric shielding due to
their variable imino substituents. In both families of catalysts, the coligand X-which is directly involved in the
electrophilic activation step in the catalytic cycle-will be varied and optimized according to established methods in
coordination chemistry and according to the polymerization reaction under study. Both apolar (olefins) and polar
(metacrylates, lactones) monomers will be polymerized with these new organolanthanide catalysts.
Due to the novel intrinsic shape, size, and donor-site geometry of the triptycene and bissulfoximine ligand
architectures two new families of monomeric organolanthanide polymerization catalysts of high activity and
improved chemo- and stereoselectivity will be obtained.