Synthesis, characterization, and norbornene polymerization of eta(3)-benzylnickel(II) complexes of N-heterocyclic carbenes

• Published in: Journal of organometallic chemistry Vol. 693; no. 12; pp. 2171 - 2176
• Main Authors: Sujith, S., Noh, Eun Kyung, Lee, Bun Yeoul, Han, Jin Wook
• Format: Journal Article
• Language: English
• Published: LAUSANNE Elsevier 01.06.2008
• Subjects: Chemistry; Chemistry, Inorganic & Nuclear; Chemistry, Organic; Physical Sciences; Science & Technology; POLYNORBORNENE; eta-benzylnickel complex; BEHAVIOR; OLEFIN POLYMERIZATION; REACTIVITY; carbene ligand; ETHYLENE POLYMERIZATION; polymerization catalysis; LIGANDS; MOLECULAR-STRUCTURES; OLIGOMERIZATION; MICROSTRUCTURE; NEUTRAL NICKEL(II) CATALYSTS
• ISSN: 0022-328X
• DOI: 10.1016/j.jorganchem.2008.03.026

Neutral eta(1)-benzylnickel carbene complexes, [Ni(eta(1)-CH(2)C(6)H(5))(IiPr)(PMe(3))(Cl)] (3) (IiPr = 1,3-bis-(2, 6-diisopropylphenyl)imidazol-2-ylidene) and [Ni(eta(1)-CH(2)C(6)H(5))(SIiPr)(PMe(3))(Cl)] (4) (SIiPr = 1,3-bis-(2, 6-diisopropylphenyl)imidazolin-2-ylidene), were prepared by the reaction between [Ni(eta(3)CH(2)C(6)H(5))(PMe(3))(Cl)] and an equivalent amount of the corresponding free N-heterocyclic carbene. The preparation of eta(3)-benzylnickel carbene complexes, [Ni(eta(3)-CH(2)C(6)H(5))(IiPr)(Cl)] (5) and [Ni(eta(3)CH(2)C(6)H(5))( SIiPr)(Cl)] (6) were carried out by the abstraction of PMe3 from 3 and 4 by the treatment of B(C(6)F(5))(3). The treatment of AgX on 5 and 6 produced the anion-exchanged complexes, [Ni(eta(3)CH(2)C(6)H(5))( NHC)(X)] (7, NHC = IiPr, X = O(2)CCF(3); 8, NHC = IiPr, X = O(3)SCF(3); 9, NHC = SIiPr, X = O(2)CCF(3); 10, NHC = SIiPr, X = O3SCF3). The solid state structures of 3 and 10 were determined by X-ray crystallography. The eta(3)-benzyl complexes of IiPr (5, 7, and 8) alone, in the absence of any activators such as borate and MAO, showed good catalytic activity towards the vinyl-type norbornene polymerization. The catalyst was thermally robust and the activity increases as the temperature rises to 130 degrees C. (C) 2008 Elsevier B.V. All rights reserved.