Józef Utko

Syntheses, structure, and reactivity of chiral titanium compounds: procatalysts for olefin polymerization.

Titanium complexes with chelating alkoxo ligands have been synthesised with the aim to investigate titanium active centres in catalytic ethylene polymerisation. The titanium complexes cis-[TiCl2(eta2-maltolato)2] (1, 89%), and cis-[TiCl2(eta2-guaiacolato)2] (2, 80%) were prepared by direct reaction of TiCl4 with maltol and guaiacol in toluene. The addition of maltol to [Ti(OiPr)4] in THF results in the formation of species [Ti(OiPr)2(maltolato)2] (3, 82%). The titanium compound cis-[Ti(OEt)2(eta2-maltolato)2] (4, 74%) was obtained by the transesterification reaction of species 3 with CH3CO2Et. When compound 4 is dissolved in THF a dinuclear species [Ti2(mu-OEt)2(OEt)4-(eta2-maltolato)2] (5, 45%) is formed. Reaction of [Ti(OiPr)4] with crude guaiacol in THF yields a solid, which after recrystallisation from acetonitrile gives [Ti4(mu-O)4(eta2-guaiacolato)] x 4CH3CN (6, 55%). In contrast, reaction of TiCl4 with crude guaiacol in tetrahydrofuran affords [Ti2(mu-O)Cl2(eta2-guaiacolato)4] (7, 82%). Crystallographic and electrochemical analyses of these complexes demonstrate that maltolato and guaiacolato ligands can be used as a valuable alternative for the cyclopentadienyl ring. These complexes have been shown to be active catalysts upon combination with the appropriate activator.

The crystal structure of tetrachloro(diethylphthalate)titanium(IV)

Abstract The crystal structure of [C 6 H 4 (OCOC 2 H 5 ) 2 TiCl 4 ], which in the presence of activators is a good catalyst for olefin polymerization, has been determined by X-ray diffraction methods and refined by full-matrix least-squares techniques to R = 0.045 for 2000 independent non-zero reflexions. Crystals are orthorhombic, space group Pnma , with four molecules in a cell of dimensions: a 11.45(1), b 14.07(1), c 10.56(1) A. The structure consists of discrete molecules possessing crystallographic m ( C s ) point symmetry. The Ti atoms are octahedrally coordinated by four chlorine atoms and two carbonyl oxygen atoms of diethylphthalate. The chelating ligand atoms together with the titanium atom form a seven-membered ring with the Cl and Ti atoms located above the benzene ring.

Interaction between TiCl4 and o-, m- and p-diesters. The crystal structures of [o-C6H4(COO-i-Bu)2TiCl4] · CH2Cl2 and [p-C6H4(COOMe)2TiCl4]

Abstract The crystal structures of [ o -C 6 H 4 (COO-i-Bu) 2 TiCl 4 ] · CH 2 Cl 2 , I, and [(μ-Cl) 2 {μ- p -C 6 H 4 (COOMe) 2 }Cl 6 Ti 2 ] ∞ , II, which in the presence of activators are good catalysts for olefin polymerization, have been determined by X-ray diffraction methods and the data refined by full-matrix least-squares techniques to R = 0.049 and R = 0.028 for 1511 and 1549 independent non-zero reflections for I and II, respectively. Crystals of I are orthorhombic, space group P 2 1 2 1 2 1 with 4 molecules in a unit cell of dimensions a = 14.408(6), b = 13.717(7), c = 12.486(5) A. Crystals of II are monoclinic, space group P 2 1 / n , with four molecules in cell with a = 8.474(5), b = 13.130(7), c = 9.362(7) A and β = 109.12(5)°. The Ti atoms in I are octahedrally coordinated by four chlorine atoms and two carbonyl oxygen atoms of di-iso-butyl o -phthalate. The chelating ligand atoms and the titanium atom together form a seven-membered ring. Compound II in crystalline state is a linear polymer formed by the dimeric units Cl 3 Ti(μ-Cl) 2 TiCl 3 connected together by two carbonyl oxygen atoms of p -C 6 H 4 (COOMe) 2 .

Syntheses, structure, and properties of a manganese-calcium cluster containing a Mn4Ca2 core.

We describe here a novel, simple, efficient self-assembly method for the in situ generation of [Mn4Cl4(micro-OCH2CH2OMe)4(EtOH)4] and [Mn4(micro-Cl)Cl3(micro-OCH2CH2OMe)4(HOCH2CH2OMe)3]2 cubane-type compounds which react readily with calcium species to form cluster [Mn4Ca2Cl4(micro-OCH2CH2OMe)8], the calcium atoms attached to the Mn4 unit of flatten out the cubane inducing significant conformational changes.

MgCl2 - one of the factors controlling the mechanism of the reaction between grignard reagents and titanium or zirconium tetrachloride. II

Summary Treatment of a Grignard reagent of [MgR 2 (THF) 2 ] with zirconium or titanium tetrachloride gives [MgCl 2 (THF) 2 ], which when treated with [MCl 4 (THF) 2 ] (M = Ti or Zr) yields the compounds: [Mg(THF) 6 ][ZrCl 6 ] (I), [Mg(THF) 6 ][ZrCl 5 (THF)] 2 (II), [Mg(THF) 6 ][TiCl 5 (THF)] 2 ] (IV), [(THF) 4 Mg(μ-Cl) 2 TiCl 4 ] (V) and [Mg 2 (μ-Cl) 3 (THF) 6 [TiCl 5 (THF)] (VI), along with MR 4 . The zirconium compounds I and II are insoluble in THF, which results in a decrease of the ZrR 4 yield. The titanium compounds IV, V and VI are transient intermediates in the formation of TiR 4 .

TiIV and Mov complexes with diesters. The crystal structure of [o-C6H4(CO2CH2CH2Ph)2Cl4Ti], [C2O4(CH2CH2Ph)2Cl4Ti] and [o-C6H4(CO2Et)2Cl3MoO] · C6H6

The crystal structures of [o-C6H4(CO2CH2CH2Ph)2Cl4Ti] (I), in the presence of activators a good catalyst for olefin polymerization, [C2O4(CH2CH2Ph)2Cl4Ti] (II) and [o-C6H4(CO2Et)2Cl3MoO] (III), have been determined by X-ray diffraction methods and refined by a full-matrix least-squares technique to R = 0.036, 0.041 and 0.055 for 2775, 2437 and 2776 independent non-zero reflections for I, II and III, respectively. The crystals of I are triclinic, space group P1 with two molecules in a unit cell of dimensions a = 10.475(8), b = 10.078(9), c = 13.683(9) A, α = 88.75(7) β = 72.65(6) γ = 66.95(7)°. The crystals of II are monoclinic, space group P21/c, with four molecules in a cell with a = 10.045(8), b = 21.032(22), c = 13.193(9) A, β = 128.91(6)°. The titanium atoms in I and II are octahedrally coordinated by four chlorine and two carbonyl oxygen atoms of coordinated o-diester molecules in the cis position. The crystals of III are triclinic, space group P1, with two molecules in a unit cell of dimensions a = 9.722(12), b = 8.073(12), c = 15.683(21) A, α = 83.46(9), β = 75.81(9), γ = 67.74(9)°. Three Cl atoms, one oxo oxygen and two O atoms of the carbonyl groups form a distorted octahedron around the molybdenum atom. The chelate ligand atoms and the titanium atom in I or molybdenum atom in III form a seven-membered ring which is five-membered in II.

Synthesis, magnetic properties and structure of the [Co4(μ3-Cl)2(μ2-Cl)4Cl2(THF)6] complex

Abstract The X-ray analysis showed that the title compound is isomorphous with the iron analogue reported previously. It exists as the centrosymmetric tetramer with two different types of cobalt(II) centres corresponding to octahedral CoCl4O2 and trigonal bipyramidal CoCl4O chromophores. The four cobalt atoms, bridged by two μ3- and four μ2-chlorine atoms, constitute a rhombus of dimensions: 3.686(3), 3.646(3) (edges) and 3.630(3), 6.37(1) A (diagonals). The magnetic susceptibility measured over the range 4.2–293 K suggests overall ferromagnetic interactions in the tetrameric molecule. Attempts have been made to simulate the magnetism of the tetramer with the isotropic Heisenberg model. The magnetic properties of the title compound are compared to those of its iron analogue.

Reaction of MgCl2 with AlCl3 in ethyl acetate. The crystal structure of [Mg(CH3OCOC2H5)6][AlCl4]2

Abstract The direct reaction of [MgCl 2 (CH 3 OCOC 2 H 5 ) 2 ] with AlCl 3 (CH 3 OCOC 2 H 5 ) 2 in ethyl acetate yields the colourless crystalline salt formulated as [Mg(CH 3 OCOC 2 H 5 ) 6 ][AlCl 4 ] 2 . The crystal structure of this compound has been determined by an X-ray diffraction study. Crystals are cubic, space group Pa 3 − with a 16.61(1) A and Z = 4. The structure was refined by full-matrix least squares to R = 0.061 for 806 independent non-zero reflections. The crystal contains [Mg(CH 3 OCOC 2 H 5 ) 6 ] 2+ cations, which show 3 − ( C 3 i ) symmetry, and [AlCl 4 ] − anions, which are in a three-fold axis.

The crystal structure and properties of di-μ-m-diethylphthalateoctachlorodititanium(IV)

Abstract The crystal structure of dimeric {Ti 2 [μ- m -C 6 H 4 (COOET) 2 ] 2 Cl 8 }, which in the presence of activators is a good catalyst for olefin polymerization, has been determined by X-ray diffraction and refined by full-matrix least squares to R = 0.0333 for 1990 independent non-zero reflexions. Crystals are triclinic, space group P 1 , Z = 1, in a cell of dimensions: a = 8.940(5), b = 10.466(8), c = 10.427(8) A, α = 97.28(6), β = 107.61(4), γ = 108.13(4)°. The crystal consists of dimeric molecules possessing crystallographic symmetry centre. The titanium atoms are octahedrally coordinated by four chlorine atoms and two carbonyl oxygen atoms of the two m -diethylphthalate in the cis position. The two ester ligands and the two Ti atoms form a sixteen-membered ring. The phenyl rings are not quite planar; the average separation between them is 3.36(1) A.

The crystal structure and properties at [AlCl3(C6H5COOC2H5]

The direct reaction of AlCl3 with ethyl benzoate in n-hexane gives the colourless crystalline compound [AlCl3(C6H5COOC2H5)], the crystal structure of which has been determined by X-ray single crystal diffraction methods. Crystals are orthorhombic, space group Pnma with a = 15.016(9), b = 7.166(6), c = 12.009(8) A, and Z = 4. The structure was refined by block-diagonal least-squares to R = 0.049 for 1293 independent non-zero reflections. The aluminium atom is tetrahedrally coordinated by three chlorine atoms and by the carbonyl oxygen atom of ethyl benzoate.