Preparation of Pyridylamido Hafnium Complexes for Coordinative Chain Transfer Polymerization

The pyridylamido hafnium complex (I) discovered at Dow is a flagship catalyst among postmetallocenes, which are used in the polyolefin industry for PO-chain growth from a chain transfer agent, dialkylzinc. In the present work, with the aim to block a possible deactivation process in prototype compound I, the corresponding derivatives were prepared. A series of pyridylamido Hf complexes were prepared by replacing the 2,6-diisopropylphenylamido part in I with various 2,6-R2C6H3N-moieties (R = cycloheptyl, cyclohexyl, cyclopentyl, 3-pentyl, ethyl, or Ph) or by replacing 2-iPrC6H4C(H)- in I with the simple PhC(H)-moiety. The isopropyl substituent in the 2-iPrC6H4C(H)-moiety influences not only the geometry of the structures (revealed by X-ray crystallography), but also catalytic performance. In the complexes bearing the 2-iPrC6H4C(H)-moiety, the chelation framework forms a plane; however, this framework is distorted in the complexes containing the PhC(H)-moiety. The ability to incorporate α-olefin decreased upon replacing 2-iPrC6H4C(H)-with the PhC(H)-moiety. The complexes carrying the 2,6-di(cycloheptyl)phenylamido or 2,6-di(cyclohexyl)phenylamido moiety (replacing the 2,6-diisopropylphenylamido part in I) showed somewhat higher activity with greater longevity than did prototype catalyst I.

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Preparation of Half- and Post-Metallocene Hafnium Complexes with Tetrahydroquinoline and Tetrahydrophenanthroline Frameworks for Olefin Polymerization

Polymers ◽

10.3390/polym11071093 ◽

2019 ◽

Vol 11 (7) ◽

pp. 1093 ◽

Cited By ~ 1

Author(s):

Jun Won Baek ◽

Su Jin Kwon ◽

Hyun Ju Lee ◽

Tae Jin Kim ◽

Ji Yeon Ryu ◽

...

Keyword(s):

Chain Transfer ◽

Olefin Polymerization ◽

Ion Pair ◽

Metallocene Catalysts ◽

Active Complex ◽

Ethylene Propylene ◽

X Ray ◽

X Ray Crystallography ◽

Chain Transfer Polymerization ◽

Metallocene Complexes

Hafnium complexes have drawn attention for their application as post-metallocene catalysts with unique performance in olefin polymerization. In this work, a series of half-metallocene HfMe2 complexes, bearing a tetrahydroquinoline framework, as well as a series of [Namido,N,Caryl]HfMe2-type post-metallocene complexes, bearing a tetrahydrophenanthroline framework, were prepared; the structures of the prepared Hf complexes were unambiguously confirmed by X-ray crystallography. When the prepared complexes were reacted with anhydrous [(C18H37)2N(H)Me]+[B(C6F5)4]−, desired ion-pair complexes, in which (C18H37)2NMe coordinated to the Hf center, were cleanly afforded. The activated complexes generated from the half-metallocene complexes were inactive for the copolymerization of ethylene/propylene, while those generated from post-metallocene complexes were active. Complex bearing bulky isopropyl substituents (12) exhibited the highest activity. However, the activity was approximately half that of the prototype pyridylamido-Hf Dow catalyst. The comonomer incorporation capability was also inferior to that of the pyridylamido-Hf Dow catalyst. However, 12 performed well in the coordinative chain transfer polymerization performed in the presence of (octyl)2Zn, converting all the fed (octyl)2Zn to (polyolefinyl)2Zn with controlled lengths of the polyolefinyl chain.

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Catalytic Activity of Polynuclear vs. Dinuclear Aroylhydrazone Cu(II) Complexes in Microwave-Assisted Oxidation of Neat Aliphatic and Aromatic Hydrocarbons

Molecules ◽

10.3390/molecules24010047 ◽

2018 ◽

Vol 24 (1) ◽

pp. 47 ◽

Cited By ~ 13

Author(s):

Manas Sutradhar ◽

Tannistha Barman ◽

Armando Pombeiro ◽

Luísa Martins

Keyword(s):

Catalytic Activity ◽

Aromatic Hydrocarbons ◽

Catalytic Performance ◽

Antiproliferative Agents ◽

One Dimensional ◽

X Ray ◽

X Ray Crystallography ◽

Mild Conditions ◽

Microwave Assisted ◽

Aliphatic And Aromatic Hydrocarbons

One-dimensional (1D) polynuclear Cu(II) complex (1) derived from (5-bromo-2-hydroxybenzylidene)-2-hydroxybenzohydrazide (H2L) is synthesized and characterized by elemental analysis, IR spectroscopy, ESI-MS, and single crystal X-ray crystallography. Its catalytic performance towards the solvent-free microwave-assisted peroxidative oxidation of aliphatic and aromatic hydrocarbons under mild conditions is compared with that of dinuclear Cu(II) complexes (2 and 3) of the same ligand, previously reported as antiproliferative agents. Polymer 1 exhibits the highest activity, either for the oxidation of cyclohexane (leading to overall yields, based on the alkane, of up to 39% of cyclohexanol and cyclohexanone) or towards the oxidation of toluene (selectively affording benzaldehyde up to a 44% yield), after 2 or 2.5 h of irradiation at 80 or 50 °C, respectively.

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Structure and photochemical properties of biindenylidene derivatives in the solid state

Journal of Chemical Research ◽

10.3184/030823408x375133 ◽

2008 ◽

Vol 2008 (11) ◽

pp. 647-649

Author(s):

Xu Li ◽

Ping Wang ◽

Jing-jun Liu ◽

Yong-ming Wang ◽

Hai Zhu

Keyword(s):

Solid State ◽

Crystal Structures ◽

Organic Radical ◽

Compound I ◽

X Ray ◽

Photochromic Compounds ◽

X Ray Crystallography ◽

Photochemical Properties ◽

Compound Ii

Two photochromic compounds, trans-3,3′-dipentyl-3,3′-dihydroxy-2,2′-bi-1H-indene-1,1′-dione (I), and cis-3,3′-di (2-methylally)-3,3′-dihydroxy-2,2′-bi-1H-indene-1,1′-dione (II), were synthesised and their crystal structures were determined by X-ray crystallography. The photoinduced properties of the compound were studied. The results showed that compound I exhibited reversible photochromism, and at the same time a stable organic radical was generated, while compound II did not show photochemical properties.

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Living Coordinative Chain-Transfer Polymerization and Copolymerization of Ethene, α-Olefins, and α,ω-Nonconjugated Dienes using Dialkylzinc as “Surrogate” Chain-Growth Sites

Macromolecules ◽

10.1021/ma801962v ◽

2008 ◽

Vol 41 (21) ◽

pp. 7829-7833 ◽

Cited By ~ 89

Author(s):

Wei Zhang ◽

Jia Wei ◽

Lawrence R. Sita

Keyword(s):

Chain Transfer ◽

Chain Growth ◽

Chain Transfer Polymerization

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Kupfer- und Goldkomplexe von Dithiocarbaminsäureestern. Strukturen von [CuCI(L1)3] · CH2Cl2, [AuCl(L1)2], [CuI(L1)(PPh3)]2 und [Cu2ICuIICl4(L2)2]n (L1 = N-Phenyl-S-methyldithiocarbaminsäureester, L2 = N,N-Dimethyl-S-methyldithiocarbaminsäureester) / Copper and Gold Complexes of Dithiocarbamate Esters. X-Ray Structures of [CuCl(L1)3] · CH2Cl2, [AuCl(L1)2], [CuI(L1)(PPh3)]2 and [Cu2ICuIICl4(L2)2]n (L1 = N-Phenyl-S-methyldithiocarbamate, L2 = N,N-Dimethyl-S-methyldithiocarbamate)

Zeitschrift für Naturforschung B ◽

10.1515/znb-1993-0911 ◽

1993 ◽

Vol 48 (9) ◽

pp. 1227-1233 ◽

Cited By ~ 5

Author(s):

Klaus Schulbert ◽

Rainer Mattes

Keyword(s):

Mixed Valence ◽

Chain Structure ◽

Metal Centers ◽

X Ray ◽

X Ray Crystallography ◽

Square Planar ◽

Coordination Spheres ◽

A Chain ◽

Identity Period ◽

Mixed Valence Complex

Reactions of N-phenyl-S-methyldithiocarbamate (L1) and N,N-dimethyl-S-methyldithio-carbamate (L2) with CuCl2, [Cu2I2(PPh3)3] and HAuCl4 yield the complexes [CuCl(L1)3] • CH2Cl2 (1), [AuCl(L1)2] (2), [CuI(L1)(PPh3)]2 (3) and [Cu2ICuIICl4(L2)2]n (4). Their structures have been determined by single crystal X-ray crystallography. 1 and 2 are monomeric, with Cu(I) tetrahedrally four-coordinate and Au(I) two-coordinate with an S-Au-S angle of 158.2(1)°. 3 is dimeric with a central CuI2Cu core, the Cu•••Cu distance of which [314.9(1) pm] is rather large. The mixed valence complex 4 has a chain structure with the identity period CuII(μ-Cl)2CuI(μ-S)2CuI(μ-Cl)2. CuI is in a tetrahedral, CuII in a square planar environment. The (μ-S)2 bridged CuI ••• CuI distance is only 259.1(1) pm. The structures of the CuX2Cu cores of 3 and 4 are mainly determined by steric interactions of the donor atoms within the coordination spheres of the metal centers.

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Reversible addition-fragmentation chain transfer polymerization of 2-naphthyl acrylate with 2-cyanoprop-2-yl 1-dithionaphthalate as a chain-transfer agent

Journal of Polymer Science Part A Polymer Chemistry ◽

10.1002/pola.20746 ◽

2005 ◽

Vol 43 (12) ◽

pp. 2632-2642 ◽

Cited By ~ 19

Author(s):

Wei Zhang ◽

Xiulin Zhu ◽

Di Zhou ◽

Xiaoyan Wang ◽

Jian Zhu

Keyword(s):

Chain Transfer ◽

Chain Transfer Agent ◽

Reversible Addition ◽

A Chain ◽

Chain Transfer Polymerization

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Radical polymerization by a supramolecular catalyst: cyclodextrin with a RAFT reagent

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.12.244 ◽

2016 ◽

Vol 12 ◽

pp. 2495-2502 ◽

Cited By ~ 3

Author(s):

Kohei Koyanagi ◽

Yoshinori Takashima ◽

Takashi Nakamura ◽

Hiroyasu Yamaguchi ◽

Akira Harada

Keyword(s):

Aqueous Solution ◽

Molecular Weight ◽

Complex Formation ◽

Radical Polymerization ◽

Chain Transfer ◽

Reaction Yield ◽

Host Molecule ◽

Narrow Molecular Weight Distribution ◽

X Ray ◽

A Chain

Supramolecular catalysts have received a great deal of attention because they improve the selectivity and efficiency of reactions. Catalysts with host molecules exhibit specific reaction properties and recognize substrates via host–guest interactions. Here, we examined radical polymerization reactions with a chain transfer agent (CTA) that has α-cyclodextrin (α-CD) as a host molecule (α-CD-CTA). Prior to the polymerization of N,N-dimethylacrylamide (DMA), we investigated the complex formation of α-CD with DMA. Single X-ray analysis demonstrated that α-CD includes DMA inside its cavity. When DMA was polymerized in the presence of α-CD-CTA using 2,2'-azobis[2-(2-imidazolin-2-yl)propane dihydrochloride (VA-044) as an initiator in an aqueous solution, poly(DMA) was obtained in good yield and with narrow molecular weight distribution. In contrast, the polymerization of DMA without α-CD-CTA produced more widely distributed polymers. In the presence of 1,6-hexanediol (C6 diol) which works as a competitive molecule by being included in the α-CD cavity, the reaction yield was lower than that without C6 diol.

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Phenyl-Terminated Polyolefins via Living Coordinative Chain Transfer Polymerization with ZnPh2 as a Chain Transfer Agent

ACS Catalysis ◽

10.1021/acscatal.1c02038 ◽

2021 ◽

pp. 10170-10178

Author(s):

Mark A. Wallace ◽

Aaron A. Burkey ◽

Lawrence R. Sita

Keyword(s):

Chain Transfer ◽

Chain Transfer Agent ◽

A Chain ◽

Chain Transfer Polymerization

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Die Verbindung MgCl2·2AsCl3·5THF: ein Tetrachloroarsenat(III) oder ein AsCl3-Solvat des MgCl2 · 4THF? / The Compound MgCl2·2AsCl3·5THF: A Tetrachloroarsenate(III) or an AsCl3 Solvate of MgCl2·4THF?

Zeitschrift für Naturforschung B ◽

10.1515/znb-1996-0720 ◽

1996 ◽

Vol 51 (7) ◽

pp. 1033-1036

Keyword(s):

Chain Structure ◽

X Ray ◽

X Ray Crystallography ◽

Weakly Interacting ◽

A Chain ◽

Cl Atoms

A compound MgX2·2AsX3 · 5THF (X = Cl, Br) has first been obtained by chance during an attempt to prepare mesitylarsenic dichloride from AsCl3 and mesitylmagnesium bromide. Then, MgCl2 · 2AsCl3 · 5THF was synthesized from the components. X-ray crystallography revealed that this compound is best described as [trans-MgCl2(THF)4)]·(2AsCl3 · THF). The AsCl3 units are weakly interacting with the Cl atoms of the MgCl2(THF)4 molecules, while the fifth THF molecule interacts with both AsCl3 units making the As atoms hexacoordinated. This arrangement generates a chain structure in the orthorhombic lattic.

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