Early Metal Di(pyridyl) Pyrrolide Complexes with Second Coordination Sphere Arene−π Interactions: Ligand Binding and Ethylene Polymerization

Early
metal complexes supported by hemilabile, monoanionic di­(pyridyl)
pyrrolide ligands substituted with mesityl and anthracenyl groups
were synthesized to probe the possibility of second coordination sphere
arene−π interactions with ligands with potential for
allosteric control in coordination chemistry, substrate activation,
and olefin polymerization. Yttrium alkyl, indolide, and amide complexes
were prepared and structurally characterized; close contacts between
the anthracenyl substituents and Y-bound ligands are observed in the
solid state. Titanium, zirconium, and hafnium tris­(dimethylamido)
complexes were synthesized, and their ethylene polymerization activity
was tested. In the solid state structure of one of the Ti tris­(dimethylamido)
complexes, coordination of Ti to only one of the pyridine donors is
observed pointing to the hemilabile character of the di­(pyridyl) pyrrolide
ligands.