Syntheses of iron, cobalt, chromium, copper and zinc complexes with bulky bis(imino)pyridyl ligands and their catalytic behaviors in ethylene polymerization and vinyl polymerization of norbornene

Chen, Jianxin; Huang, Yuan–Biao; Li, Zhongshui; Zhi-Chun, Zhang; Chen, Wei; Lan, Ting-Yan; Zhang, Wenjie

doi:10.1016/j.molcata.2006.06.016

Cited by 64 publications

(3 citation statements)

References 47 publications

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“…Generally for a given aniline, the condensation reaction occurs more readily for 2,6-pyridinedicarboxaldehyde than for 2,6-diacetylpyridine, while 2,6-dibenzoylpyridine is much less reactive under these conditions. Using this simple approach a wide variety of symmetrical examples of 1 have been prepared in which the steric bulk and electronic properties of the aryl groups have been systematically varied (see Tables 1 and 2 for complexed examples [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,17,20,21,24,26,27,29,28,32,33,36,37,38,39,40,41,42,44,48,18,16,19,22,23,25,30,31,34,35,45,43,46,…”

Section: Ligand Preparationmentioning

confidence: 99%

Iron-Based and Cobalt-Based Olefin Polymerisation Catalysts

Gibson¹,

Solan²

2008

Topics in Organometallic Chemistry

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This chapter describes the brief history of iron or cobalt catalysts for olefin polymerisation and oligomerisation. Since the discovery in 1998 that 2,6-bis(imino)pyridine iron and cobalt halides, on activation with MAO, can convert ethylene to highly linear polyethylene, numerous reports have been concerned with ligand modification, mechanisms for precatalyst activation, identifying the active species and understanding the mode of propagation/chain transfer. In addition, heterogenisation of this class of catalysts, their incorporation into macrocycles/ polymers and their use in reactor blending/tandem catalysis has seen some important developments; alternative ligand architectures that can support active iron and cobalt catalysts are also discussed as are different types of olefinic monomer.

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Section: Ligand Preparationmentioning

confidence: 99%

Iron-Based and Cobalt-Based Olefin Polymerisation Catalysts

Gibson¹,

Solan²

2008

Topics in Organometallic Chemistry

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“…The ligand derives much of its popularity from the formation of active polymerization catalysts in combination with Fe and Co, as originally reported by Brookhart and Gibson . Since then, combinations with virtually all redox-active first-row transition metals have been studied extensively: for just a few references see V, , Cr, , Mn, − Fe, − Co, ,− Ni, − and Cu. − Many of these studies have focused on ligand-centered redox activity and/or olefin polymerization (the latter reported not only for Fe and Co but also for Cr and V , complexes). Surprisingly, only a single paper mentions the combination of DIP with titanium.…”

Section: Introductionmentioning

confidence: 99%

Balance between Metal and Ligand Reduction in Diiminepyridine Complexes of Ti

2017

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Reaction of the diiminepyridine ligand Et DIP (2,6-Et 2 -C 6 H 3 NCMe) 2 C 5 H 3 N) with TiCl 3 (THF) 3 gave the corresponding Ti(III) complex ( Et DIP)TiCl 3 (1). Reduction of 1 with 1 equiv of KC 8 produced the formally Ti(II) complex ( Et DIP)TiCl 2 (2). From this, ( Et DIP)TiClR complexes (R = Me (3a), Me 3 SiCH 2 (3b), Ph (3c)) were obtained by addition of 1 equiv of RLi. Similarly, dialkyl complexes ( Et DIP)TiR 2 (R = Me (4a), Me 3 SiCH 2 (4b)) were obtained with 2 equiv of RLi. All new complexes except 3b were characterized by single-crystal X-ray diffraction. EPR studies indicate that complex 1 is best regarded as a true Ti(III) complex with an "innocent" DIP ligand. Complexes 2−4 are all diamagnetic. In contrast to DIP complexes of the late transition metals Fe and Co, the new complexes 2−4 show strong upfield 1 H NMR shifts for the pyridine β and γ protons caused by transfer of negative charge to the DIP ligand. On the basis of this and the CN and C imine −C Py bond lengths, a description involving Ti(IV) and a dianionic ligand seems most appropriate, and DFT calculations support this interpretation. This means that reduction of Ti(III) complex 1 results in oxidation of the metal center to Ti(IV). VT-NMR studies of 4a suggest a small and temperature-dependent thermal population of a triplet state, and indeed calculations indicate that 4a has the lowest singlet− triplet energy difference of the systems studied.

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“…So the design and synthesis of catalysts are very important. It is well known that the vinyl addition polymerization of norbornene can be efficiently proceeded using conventional Ziegler-Natta catalysts [13,14], metallocene catalysts [15][16][17], late transition metal catalysts [18][19][20][21][22][23][24][25][26][27][28][29][30]. Among these catalysts, because of lower oxophilicity and resistance toward deactivation by polar functionalities, the late transition metal catalysts has received renewed interest.…”

Section: Introductionmentioning

confidence: 99%

Vinylic copolymerization of norbornene and higher 1-alkene with three-dimensional geometry binickel catalyst

Huo

Guang-quan

2015

J Polym Res

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Compared with monometallic complex, the threedimensional geometry α-diimine binickel complex exhibited higher activities (5.5×10 5 -2.7×10 7 g polymer /mol Ni ·h) in the homopolymerization of norbornene and copolymerization of norbornene with 1-hexene or 1-decene in the presence of B(C 6 F 5 ) 3 . The 1-hexene or 1-decene content in the copolymers could be controlled up to 9.2-25.3 % or 8.8-17.8 % by varying the comonomer feed ratios 1-hexene or 1-decene from 10 to 50 %. It was observed that the yield depended on the kind of 1-alkene and improved with increasing the length of 1-alkene. The obtained poly(NB-co-1-hexene)s and poly(NBco-1-decene)s exhibited high thermal stability and high glass transition temperature, together with high molecular weight. In addition, copolymers showed good solubility in common organic solvents and could be processed into films by solution casting method, which showed good transparency in the visible region.

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Syntheses of iron, cobalt, chromium, copper and zinc complexes with bulky bis(imino)pyridyl ligands and their catalytic behaviors in ethylene polymerization and vinyl polymerization of norbornene

Cited by 64 publications

References 47 publications

Iron-Based and Cobalt-Based Olefin Polymerisation Catalysts

Iron-Based and Cobalt-Based Olefin Polymerisation Catalysts

Balance between Metal and Ligand Reduction in Diiminepyridine Complexes of Ti

Vinylic copolymerization of norbornene and higher 1-alkene with three-dimensional geometry binickel catalyst

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