Covalent titanium aryldioxy one-, two-, and three-dimensional networks and their examination as Ziegler-Natta catalysts.

Treatment of ((i)PrO)4Ti with 2,7-dihydroxynaphthalene at 100 degrees C afforded the one-dimensional ladder [cis-Ti(mu(2,7)-OC10H6O)2py2]n (1: C30H22N2O4Ti, orthorhombic, P2(1)2(1)2(1), a = 9.866(2) A, b = 15.962(3) A, c = 16.223(3) A, 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, P1, a = 10.814(2) A, b = 16.785(3) A, c = 18.020(4) A, alpha = 93.88(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.

A covalent vanadium(III) 2-dimensional network and vanadyl chains linked by aryldioxides.

Thermolysis of (iPrO)4V and 2,6-dihydroxynaphthalene in 4-(3-phenylpropyl)pyridine afforded [mer-V(mu 2,6-OC10H6O)1.5(4-(3-phenylpropyl)py)3]n (1; C57H54N3O3V, triclinic, P1, a = 10.450(2) A, b = 14.098(3) A, c = 16.765(3) A, alpha = 100.09(3) degrees, beta = 103.85(3) degrees, gamma = 103.08(3) degrees, Z = 2) and oxidation product bis-2,6-dinaphthol. Paramagnetic (S = 1) 1 adopts a bricklike motif of aryldioxide-connected V(III) centers whose channels are filled with the bound 4-(3-phenylpropyl)py. A similar procedure involving (iPrO)3VO provided the linear chain [(mu 2,6-OC10H6O)(4-(3-phenylpropyl)py)2VO]n (2; C38H36N2O3V, monoclinic, P2(1)/c, a = 10.6172(2) A, b = 9.4477(3) A, c = 31.8129(8) A, beta = 95.20(3) degrees, Z = 4). Interchain pyridine ring-edge to phenyl-face interactions generate a sheet of like-oriented oxos, but adjacent sheets are oriented in opposition so that no net dipole exists. Another 1-dimensional chain, [(mu 1,4-OC6H4O)(py)2VO]n (3; C16H14N2O3V, monoclinic, P2(1)/c, a = 8.377(2) A, b = 16.675(3) A, c = 11.061(2) A, beta = 103.91(3) degrees, Z = 4), was prepared by heating (iPrO)4V and hydroquinone in pyridine. Pyridines of adjacent chains interpenetrate to form a sheet, but oxos in adjacent chains are now in opposition.

Covalent metal-organic networks: pyridines induce 2-dimensional oligomerization of (mu-OC6H4O)2Mpy2 (M = Ti, V, Zr).

Treatment of M(OiPr)4 (M = Ti, V) and [Zr(OEt)4]4 with excess 1,4-HOC6H4OH in THF afforded [M(OC6H4O)a(OC6H4OH)3.34-1.83a(OiPr)0.66-0.17a(THF)0.2]n (M = Ti, 1-Ti; V, 1-V, 0.91 < or = a < or = 1.82) and [Zr(1,4-OC6H4O)2-x(OEt)2x]n (1-Zr, x = 0.9). The combination of of 1-M (M = Ti, V, Zr) or M(OiPr)4 (M = Ti, V), excess 1,4- or 1,3-HOC6H4OH, and pyridine or 4-phenylpyridine at 100 degrees C for 1 d to 2 weeks afforded various 2-dimensional covalent metal-organic networks: [cis-M(mu 1,4-OC6H4O)2py2] infinity (2-M, M = Ti, Zr), [trans-M(mu 1,4-OC6H4O)2py2.py] infinity (3-M, M = Ti, V), solid solutions [trans-TixV1-x(mu 1,4-OC6H4O)2py2.py] infinity (3-TixV1-x, x approximately 0.4, 0.6, 0.9), [trans-M(mu 1,4-OC6H4O)2(4-Ph-py)2] infinity (4-M, M = Ti, V), [trans-Ti(mu 1,3-OC6H4O)2py2] infinity (5-Ti), and [trans-Ti(mu 1,3-OC6H4O)2(4-Ph-py)2] infinity (6-Ti). Single-crystal X-ray diffraction experiments confirmed the pleated sheet structure of 2-Ti, the flat sheet structure of 3-Ti, and the rippled sheet structures of 4-Ti, 5-Ti, and 6-Ti. Through protolytic quenching studies and by correspondence of powder XRD patterns with known titanium species, the remaining complexes were structurally assigned. With py or 4-Ph-py present, aggregation of titanium centers is disrupted, relegating the building block to the cis- or trans-(ArO)4Tipy2 core. The sheet structure types are determined by the size of the metal and the interpenetration of the layers, which occurs primarily through the pyridine residues and inhibits intercalation chemistry.