Tridentate iminopyrrolyl nickel complexes and their use as catalysts for the reaction of polymerisation of ethylene to hyperbranched polyethylene
AssigneeInstituto Superior Tecnico
InventorsPatrícia Da Silva Lopes, Cláudia Alexandra Carica Figueira, Pedro Manuel Machado Teixeira Gomes
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Abstract
The present invention relates to the preparation of novel nickel complexes containing iminopyrrolyl-type ligands, having the general molecular structure (I), and to their use as active catalysts in the polymerisation reaction of ethylene to hyperbranched polyethylene. The structure of the ligand precursor is such that it allows the occurrence of a cyclometallation reaction by the activation of a C—H bond, in the coordination reaction to the metal centre, generating a C,N,N′-tridentate complex.
Claims20
A tridentate iminopyrrolyl nickel complex represented by general molecular formula (I), in which a chelating iminopyrrolyl ligand is bonded to the nickel centre in a tridentate fashion, through a subsequent cyclometallation reaction by an intramolecular CH activation, wherein general molecular formula (I) has the structure:
- a) Ar represents an aryl group or a substituted aryl group, having one or both ortho positions of an aromatic ring substituted with C1-C4 alkyl groups, unsubstituted or substituted alkoxy or aryl groups;
- b) R1 represents a hydrogen atom or a C1-C4 alkyl group;
- c) R2 represents a hydrogen atom or a C1-C4 alkyl group or a substituted or unsubstituted aryl group;
- d) R3 represents a methylene group;
- e) R4 and R5 represent hydrogen atoms;
- f) R6 represents a hydrogen atom, a C1-C11 alkyl group, an unsubstituted or substituted aryl group or a halogen;
- g) L represents a neutral coordinating ligand selected from the group consisting of triphenylphosphine, tri(C1-C6 alkyl)phosphine, tricycloalkylphosphine, diphenylalkylphosphine, dialkylphenylphosphine, trialkylamine, arylamine, and a nitrile or equivalents.
A tridentate iminopyrrolyl nickel complex represented by general molecular formula (I), in which the iminopyrrolyl chelating ligand is bonded to the nickel centre in a tridentate fashion, through a subsequent cyclometallation reaction by a C—H intramolecular activation, wherein general molecular formula (I) has the structure:
- a) Ar represents an aryl group or a substituted aryl group, having one or both ortho positions of an aromatic ring substituted with substituted or unsubstituted alkoxy or aryl groups;
- b) R1 and R2 represent together a fused aromatic ring containing the corresponding C═C bond, substituted at least in one of the ortho positions by a methylene group (R3), but which may be or not substituted in the other positions, by different or equal substituents, that can be C1-C4 alkyl, trifluoromethyl, methoxy or halogen;
- c) R3 represents a methylene group;
- d) R4 and R5 represent hydrogen atoms;
- e) R6 represents a hydrogen atom, a C1-C11 alkyl group, a substituted or unsubstituted aryl group or a halogen;
- f) L represents a neutral coordinating ligand selected from the group consisting of triphenylphosphine, tri(C1-C6 alkyl)phosphine, tricycloalkylphosphine, diphenylalkylphosphine, dialkylphenylphosphine, trialkylamine, arylamine, and a nitrile or equivalents.
Dependencies are inferred from the claim text.