Synthesis, characterization and ethylene polymerization behaviour of binuclear nickel halides bearing 4,5,9,10-tetra(arylimino)pyrenylidenes

Pyrene-4,5,9,10-tetraone was prepared via the oxidation of pyrene, and reacted with various anilines to afford a series of 4,5,9,10-tetra(arylimino)pyrenylidene derivatives (L1–L4). The tetraimino-pyrene compounds L1 and L2 were reacted with two equivalents of (DME)NiBr₂ in CH₂Cl₂ to afford the corresponding dinickel bromide complexes (Ni1 and Ni2). The organic compounds were fully characterized, whilst the bi-metallic complexes were characterized by FT-IR spectra and elemental analysis. The molecular structures of representative organic and nickel compounds were confirmed by single-crystal X-ray diffraction studies. These nickel complexes exhibited high activities towards ethylene polymerization in the presence of either MAO or Me₂AlCl, maintaining a high activity over a prolonged period (longer than previously reported dinickel complex pre-catalysts). The polyethylene obtained was characterized by GPC, DSC and FT-IR spectroscopy and was found to possess branched features

Biphenyl-bridged 6-(1-aryliminoethyl)-2-iminopyridyl-cobalt complexes: synthesis, characterization and ethylene polymerization behavior

A series of biphenyl-bridged 6-(1-aryliminoethyl)-2-iminopyridine derivatives reacted with cobalt dichloride in dichloromethane/ethanol to afford the corresponding binuclear cobalt complexes. The cobalt complexes were characterized by FT-IR spectroscopy and elemental analysis, and the structure of a representative complex was confirmed by single-crystal X-ray diffraction. Upon activation with either MAO or MMAO, these cobalt complexes performed with high activities of up to 1.2 × 10⁷ g (mol of Co)⁻¹ h⁻¹ in ethylene polymerization, which represents one of the most active cobalt-based catalytic systems in ethylene reactivity. These biphenyl-bridged bis(imino)pyridylcobalt precatalysts exhibited higher activities than did their mononuclear bis(imino)pyridylcobalt precatalyst counterparts, and more importantly, the binuclear precatalysts revealed a better thermal stability and longer lifetimes. The polyethylenes obtained were characterized by GPC, DSC, and high-temperature NMR spectroscopy and mostly possessed unimodal and highly linear features

1-Phenyl-3-(pyren-1-yl)prop-2-en-1-one

The title compound, C25H16O, was prepared by the condens­ation reaction of pyrene-1-carbaldehyde and acetophenone in ethanol solution at room temperature. The phenyl ring forms a dihedral angle of 39.10 (11)° with the pyrene ring system. In the crystal structure, adjacent pyrene ring systems are linked by aromatic π–π stacking inter­actions, with a perpendicular inter­planar distance of 3.267 (6) Å and a centroid–centroid offset of 2.946 (7) Å

Tris[2-(pyrrol-2-ylmethyl­eneamino)eth­yl]amine

The title compound, C21H27N7, was synthesized by reaction of tris­(2-amino­ethyl)amine and pyrrole-2-carbaldehyde in ethanol at room temperature. The structure is stabilized by intra- and inter­molecular C—H⋯N and N—H⋯N hydrogen-bonding inter­actions

Geometry Constrained N-(5,6,7-Trihydroquinolin-8-ylidene)arylaminopalladium Dichloride Complexes: Catalytic Behavior toward Methyl Acrylate (MA), Methyl Acrylate-co-Norbornene (MA-co-NB) Polymerization and Heck Coupling

A new pair of plladium complexes (Pd4 and Pd5) ligated with constrained N-(5,6,7-trihydroquinolin-8-ylidene)arylamine ligands have been prepared and well characterized by 1H-, 13C-NMR and FTIR spectroscopies as well as elemental analysis. The molecular structure of Pd4 and Pd5 in solid state have also been determined by X-ray diffraction, showing slightly distorted square planar geometry around the palladium metal center. All complexes Pd1–Pd5 are revealed highly efficient catalyst in methyl acrylate (MA) polymerization as well as methyl acrylate/norbornene (MA/NB) copolymerization. In the case of MA polymerization, as high as 98.4% conversion with high molecular weight up to 6282 kg·mol−1 was achieved. Likewise, Pd3 complex has good capability to incorporate about 18% NB content into MA polymer chains. Furthermore, low catalyst loadings (0.002 mol %) of Pd4 or Pd5 are able to efficiently mediate the coupling of haloarenes with styrene affording up to 98% conversion

2,6-Dibenzhydryl-N-(2-aryliminoacenaphthylenylidene)-4-chlorobenzenamino- palladium dichlorides: Synthesis, characterization, and use as catalysts in the Heck-reaction

A series of 2,6-dibenzhydryl-N-(2-aryliminoacenaphthylenylidene)-4- chlorobenzenaminopalladium(II) chloride complexes (C1-C6) were prepared and fully characterized by FT-IR and NMR spectroscopy, and by elemental analysis. The molecular structures of representative complexes C2 and C6 were confirmed as square planar at the palladium center by single crystal X-Ray diffraction. All palladium complexes exhibited good activity in the Heck cross-coupling reaction with conversions greater than 90%. Catalytic activity trends were attributed to differences in the solubility of the pre-catalysts; palladium complexes bearing more soluble alkyl-substituents performed with higher catalytic activities. © 2012 Elsevier B.V. All rights reserved

Crystal structure of dichloro-bis-(1-butyl-1H-benzo[d]imidazole)-nickel(II), C22H28Cl2N4Ni

C22H28Cl2N4Ni, monoclinic, P21/c (no. 14), a = 9.7332(19) Å, b = 14.886(3) Å, c = 18.623(5) Å, β = 117.45(2)°, V = 2394.5(10) Å3, Z = 4, Rgt(F) = 0.0450, wRref(F2) = 0.1466, T = 293.0 K