Inorganic Chemistry, Vol.40, No.9, 2026-2033, 2001
Covalent titanium aryldioxy one-, two-, and three-dimensional networks and their examination as Ziegler-Natta catalysts
Treatment of ((PrO)-Pr-i)(4)Ti with 2,7-dihydroxynaphthalene at 100 degreesC afforded the one-dimensional ladder [cis-Ti-mu (2,7)-OC10H6O)(2)py(2)](n) (1: C30H22N2O4Ti, orthorhombic, P2(1)2(1)2(1), a = 9.866(2) Angstrom, b = 15.962(3) Angstrom, c = 16.223(3) Angstrom, Z = 4), in pyridine, and the stacked ladder, two-dimensional [Ti(mu (2,7)-OC10H6O)(2)(4-picoline)(2).4(-picoline)(0.5)](n) (2: C70H59N5O8Ti2, triclinic, P (1) over bar, a = 10.814(2) Angstrom, b = 16.785(3) Angstrom, c = 18.020 Angstrom, alpha = 93.85(3)degrees, beta = 107.31(3)degrees, gamma = 108.77(3)degrees, Z = 2), in 4-picoline. A disruption of intramolecular edge-to-face and intermolecular face-to-face,pi -stacking interactions in 1 by the Me group of the 4-picoline causes the structural change to 2. These derivatives and related two- and three-dimensional covalent metal organic networks (CMON) were assayed for ethylene and propylene polymerization activity via the addition of methylaluminoxane. CMON are mediocre Ziegler-Natta catalysts that generate polydisperse, linear polyethylene and atactic polypropylene. The data are best accommodated by viewing the degradation of CMON into numerous active sites of differing activity.