Spacially confined [M.sub.2] centers (M = Fe, Co, Ni, Zn) on a sterically bulky binucleating support: Synthesis, structures and ethylene oligomerization studies

Two new bulky aryl-bridged pyridyl-imine compartmental (pro)ligands, 2,6-{(2,6-i-Pr2C6H3)N=C(Me)C5H3N}2CH3Y where (Y=H [L.sup.1]; OH [L.sup.2]-H) are prepared in moderate to good overall yields via a Stille-type cross-coupling approach. It is found that due to the low molecular weight of the materials, the ligand frames [L.sup.1] and [[L.sup.2].sup.-] possess insufficient steric bulk to prevent chain transfer of the growing oligomeric chain.