Syntheses, structures and catalytic activity of copper(II) complexes with hydroxyindanimine ligands

A series of new hydroxyindanimine ligands [ArNdouble bond; length as m-dashCC2H3(CH3)C6H2(R)OH] (Ar = 2,6-i-Pr2C6H3, R = H (HL1), R = Cl (HL2), and R = Me (HL3)) were synthesized and characterized. Reaction of hydroxyindanimine with Cu(OAc)2 · H2O results in the formation of the mononuclear bis(hydroxyindaniminato)copper(II) complexes Cu[ArNdouble bond; length as m-dashCC2H3(CH3)C6H2(R)O]2 (Ar = 2,6-i-Pr2C6H3, R = H (1), R = Cl (2), and R = Me (3)). The complex 2′ was obtained from the chlorobenzene solution of the complex 2, which has the same molecule formula with the complex 2 but it is a polymorph. All copper(II) complexes were characterized by their IR and elemental analyses. In addition, X-ray structure analyses were performed for complexes 1, 2, and 2′. After being activated with methylaluminoxane (MAO), complexes 1–3 can be used as catalysts for the vinyl polymerization of norbornene with moderate catalytic activities. Catalytic activities and the molecular weight of polynorbornene have been investigated for various reaction conditions.