Ethylene Polymerization Using (Imino)vanadium(V) Dichloride Complexes Containing (Anilido)methyl-pyridine, -quinoline Ligands–Halogenated Al Alkyls Catalyst Systems
The effect of ligand and Al cocatalysts in ethylene polymerization, using V( N-1-adamantyl)Cl 2(L) [L = 2-(2,6-Me 2C 6H 3)NCH 2(C 9H 6N), 8-(2,6-Me 2C 6H 3)NCH 2(C 9H 6N)] and V( N-2-MeC 6H 3)Cl 2[2-(2,6-R' 2C 6H 3)NCH 2(C 5H 4N)] (R' = Me, iPr), has been explored. The reaction products in the presence of Et 2AlCl or Me 2AlCl cocatalyst were polyethylene whereas the reaction product of the 2-methylphenylimido analogues in the presence of MAO cocatalyst was 1-butene with high selectivity, suggesting that the catalyst/cocatalyst nuclearity effect plays a role in this catalysis.
References
[1]
Hagen, H.; Boersma, J.; van Koten, G. Homogeneous vanadium-based catalysts for the Ziegler–Natta polymerization of α-olefins. Chem. Soc. Rev.？2002, 31, 357–364, doi:10.1039/b205238e.
Nomura, K.; Zhang, W. (Imido)vanadium(V)-alkyl, -alkylidene complexes exhibiting unique reactivity towards olefins and alcohols. Chem. Sci.？2010, 1, 161–173, doi:10.1039/c0sc00163e.
[4]
Redshaw, C. Vanadium procatalysts bearing chelating aryloxides: structure–activity trends in ethylene polymerisation. Dalton Trans.？2010, 39, 5595–5604, doi:10.1039/b924088h.
[5]
Nomura, K.; Zhang, S. Design of vanadium complex catalysts for precise olefin polymerization. Chem. Rev.？2011, 111, 2342–2362, doi:10.1021/cr100207h.
[6]
Nomura, K.; Sagara, A.; Imanishi, Y. Olefin polymerization and ring-opening metathesis polymerization of norbornene by (arylimido)(aryloxo)vanadium(V) complexes of the type VX2(NAr)(OAr￠). Remarkable effect of aluminum cocatalyst for the coordination and insertion and ring-opening metathesis. Macromolecules？2002, 35, 1583–1590, doi:10.1021/ma0117413.
[7]
Wang, W.; Nomura, K. Remarkable effects of aluminum cocatalyst and comonomer in ethylene copolymerizations catalyzed by (arylimido)(aryloxo)vanadium complexes: efficient synthesis of high molecular weight ethylene/norbornene copolymer. Macromolecules？2005, 38, 5905–5913, doi:10.1021/ma050629s.
[8]
Wang, W.; Nomura, K. Notable effects of aluminum alkyls and solvents for highly efficient ethylene (co)polymerizations catalyzed by (arylimido)-(aryloxo)vanadium complexes. Adv. Synth. Catal.？2006, 348, 743–750, doi:10.1002/adsc.200505446.
[9]
Onishi, Y.; Katao, S.; Fujiki, M.; Nomura, K. Synthesis and structural analysis of (arylimido)vanadium(V) complexes containing phenoxyimine ligands: new, efficient catalyst precursors for ethylene polymerization. Organometallics？2008, 27, 2590–2596, doi:10.1021/om800177g.
[10]
Zhang, S.; Katao, S.; Sun, W.-H.; Nomura, K. Synthesis of (arylimido)vanadium(V) complexes containing (2-anilidomethyl)pyridine ligands and their use as the catalyst precursors for olefin polymerization. Organometallics？2009, 28, 5925–5933, doi:10.1021/om900633u.
[11]
Macchioni, A. Ion pairing in transition-metal organometallic chemistry. Chem. Rev.？2005, 105, 2039–2073, doi:10.1021/cr0300439.
[12]
Li, H.; Marks, T.J. Nuclearity and cooperativity effects in binuclear catalysts and cocatalysts for olefin polymerization. Proc. Natl. Acad. Sci. USA？2006, 103, 15295–15302, doi:10.1073/pnas.0603396103.
[13]
Bochmann, M. The chemistry of catalyst activation: the case of group 4 polymerization catalysts. Organometallics？2010, 29, 4711–4740, doi:10.1021/om1004447.
[14]
Christman, D.L. Preparation of polyethylene in solution. J. Polym. Sci. Part A-1？1972, 10, 471–487, doi:10.1002/pol.1972.150100213.
[15]
Zhang, S.; Nomura, K. Highly efficient dimerization of ethylene by (imido)vanadium complexes containing (2-anilidomethyl)pyridine ligands: notable ligand effect toward activity and selectivity. J. Am. Chem. Soc.？2010, 132, 4960–4965, doi:10.1021/ja100573d.
[16]
Igarashi, A.; Zhang, S.; Nomura, K. Ethylene dimerization/polymerization catalyzed by (adamantylimido)vanadium(V) complexes containing (2-anilidomethyl)pyridine ligands: factors affecting the ethylene reactivity. Organometallics？2012, 31, 3575–3581, doi:10.1021/om3000532.
[17]
Nomura, K.; Igarashi, A.; Katao, S.; Zhang, W.; Sun, W.-H. Synthesis and structural analysis of (imido)vanadium(V) complexes containing chelate (anilido)methyl-imine ligands: Ligand effect in ethylene dimerization. Inorg. Chem.？2013. in press.
[18]
Redshaw, C.; Rowan, M.A.; Homden, D.M.; Dale, S.H.; Elsegood, M.R.J.; Matsui, S.; Matsuura, S. Vanadyl C and N-capped tris(phenolate) complexes: influence of procatalyst geometry on catalytic activity. Chem. Commun.？2006, 3329–3331.
[19]
Wu, J.-Q.; Mu, J.-S.; Zhang, S.-W.; Li, Y.-S. Vanadium(V) complexes containing tetradentate amine trihydroxy ligands as catalysts for copolymerization of cyclic olefins. J. Polym. Sci. Part A？2010, 48, 1122–1132, doi:10.1002/pola.23868.
