Surprising activity for Group 4 polyolefin catalysts [M{(OAr)2py}Cl2(thf)] (M = Zr, Ti) bearing tridentate pyridine-2,6-bis(aryloxide) ligands

Chan, Michael C. W.; Tam, Ka-Ho; Pui, Yung-Lin; Zhu, Nianyong

doi:10.1039/b206328j

Cited by 52 publications

(48 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An attempt to prepare the THF-free analog of 1 by substituting Et 2 A C H T U N G T R E N N U N G O as the solvent in the synthesis produced only unidentified products. These observations suggest that THF is required for successful isolation of 1, as also reported for the synthesis of another 6-coordinate titanium complex bearing a pyridinediylbis[phenolato] ligand [29].…”

mentioning

confidence: 66%

Synthesis, Structure, and Polymerization Activity of a Titanium Complex with a Chelating [(Hydroxy‐κO)amino‐κN]phenolato(2−)‐κO Ligand

Kraft¹,

Huang²,

Cole³

et al. 2006

Helvetica Chimica Acta

View full text Add to dashboard Cite

Dedicated to Professor Giambattista Consiglio on the occasion of his 65th birthday A novel titanium complex with a chelating nitroxide ligand, dichloro-2-{[(hydroxy-kO)phenylaminokN)phenylmethyl}phenolato(2À)-2kO}(tetrahydrofuran)titanium (1), was synthesized and characterized by NMR spectroscopy, elemental analysis, and single-crystal X-ray crystallography. In the presence of methylaluminoxane (MAO), 1 displayed moderate activity for the polymerization of propylene.Introduction. -The past two decades have witnessed major advances in olefin poly-A C H T U N G T R E N N U N G merizations utilizing well-defined metallocene complexes [1 -4]. These advances have led to new insights on the role of catalyst structure on the polymerization behavior of transition-metal catalysts [5 -7] We have recently demonstrated that hydroxylaminato ligands derived from stable nitroxide radicals (R 2 A C H T U N G T R E N N U N G NÀO · ) are an intriguing class of hemi-labile ancillary ligands for early transition metals [37 -43]. These ligands adopt both h 2 and h 1 (i.e., kN, kO and kO) coordination modes, depending on the nature of the hydroxylamine ligand and the ancillary ligation at the Ti-atom. For example, the X-ray structure of [TiCl 3 (tempo) (tempo = 2,2,6,6-tetramethylpiperidin-1-yloxy) reveals an h 2 coordination of the tempo group to the Ti-atom, while in the complexes [TiCl 2 (Cp)(tempo)] and [TiCl(Cp) 2 A C H T U N G T R E N N U N G (tempo)], (Cp = cyclopentadienyl), tempo adopts an h 1 coordination to the metal [39] [40]. The solution measurements indicate that the h 1 ! h 2 interconversion of [TiCl 3 (tempo)] is facile at room temperature [38]. Mono(cyclopentadienyl)titanium derivatives such as [Ti(Cp*)Me 2 A C H T U N G T R E N N U N G (ONEt 2 )]/Ph 3 A C H T U N G T R E N N U N G C[B(C 6 F 5 ) 4 ] (Cp*= pentamethylcyclopentadienyl) exhibit very high activities for propylene polymerization, generating high-molecular-mass atactic polypropylenes [43]. Herein, we report the synthesis, structure, and polymerization behavior of a novel Ti complex with a chelating nitroxide ligand.

show abstract

mentioning

confidence: 66%

Synthesis, Structure, and Polymerization Activity of a Titanium Complex with a Chelating [(Hydroxy‐κO)amino‐κN]phenolato(2−)‐κO Ligand

Kraft¹,

Huang²,

Cole³

et al. 2006

Helvetica Chimica Acta

View full text Add to dashboard Cite

show abstract

“…Various types of 6-coordinated complexes based on tridentate chelate ligands have been reported [201][202][203][204][205][206][207][208][209][210][211][212][213][214][215][216][217][218][219] and in Fig. 15 some representative examples are illustrated.…”

Section: Tridentate Ligandsmentioning

confidence: 99%

Non-Cp type homogeneous catalytic systems for olefin polymerization

Park

Han

Kim

et al. 2004

Journal of Organometallic Chemistry

View full text Add to dashboard Cite

“…The bis(aryloxide) ligands linked by pyridine [41] and N-heterocyclic carbene (NHC) [42] were reported in the synthesis of titanium and zirconium complexes as shown in Schemes 13 and 14, respectively. While X-ray analysis reveals that the conformation of the pyridine-linked ligand is C s -symmetric, the NHC-linked ligand adopts a C 2 -symmetric conformation.…”

Section: Bis(aryloxide) Ligands Linked By the Heteroatom Groupmentioning

confidence: 99%

“…Alkylation of the NHC dichloro complex with PhCH 2 MgBr afforded the C 2 -symmetric benzyl complex, whose activation parameters for the enantiomerization [DH à = 64.8 kJ mol À1 ; DS à = À6.2 J mol À1 K À1 ] was determined by variabletemperature NMR studies. The titanium-pyridine complex [6]TiCl 2 with MAO were poor catalysts for the polymerization of ethene, whereas the zirconium congener showed a very high activity [41]. For the NHC complex, the activation with MMAO produced catalysts gave rise to a high activity in the polymerization of ethene.…”

Section: Bis(aryloxide) Ligands Linked By the Heteroatom Groupmentioning

confidence: 99%

Aryloxide-based multidentate ligands for early transition metals and f-element metals

Kawaguchi

Matsuo

2004

Journal of Organometallic Chemistry

View full text Add to dashboard Cite

Surprising activity for Group 4 polyolefin catalysts [M{(OAr)2py}Cl2(thf)] (M = Zr, Ti) bearing tridentate pyridine-2,6-bis(aryloxide) ligands

Cited by 52 publications

References 21 publications

Synthesis, Structure, and Polymerization Activity of a Titanium Complex with a Chelating [(Hydroxy‐κO)amino‐κN]phenolato(2−)‐κO Ligand

Synthesis, Structure, and Polymerization Activity of a Titanium Complex with a Chelating [(Hydroxy‐κO)amino‐κN]phenolato(2−)‐κO Ligand

Non-Cp type homogeneous catalytic systems for olefin polymerization

Aryloxide-based multidentate ligands for early transition metals and f-element metals

Contact Info

Product

Resources

About