Effects of Unsaturated Metal Sites on Radical Vinyl Polymerization in Coordination Nanochannels

Uemura, Takashi; Uchida, Noriyuki; Higuchi, Masakazu; Kitagawa, Susumu

doi:10.1021/ma200310x

Cited by 39 publications

(25 citation statements)

References 48 publications

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“…On the other hand, the metal‐mediated poly (methyl methacrylate) (PMMA) polymerization is of growing interest both in industry and academia due to its significant optical properties . The optical properties of PMMA are far improved with high T g , which in turn depend on tacticity of PMMA, i.e.…”

Section: Introductionmentioning

confidence: 99%

Zinc (II), palladium (II) and cadmium (II) complexes containing 4‐methoxy‐N‐(pyridin‐2‐ylmethylene) aniline derivatives: Synthesis, characterization and methyl methacrylate polymerization

Park

Lee

et al. 2019

Applied Organom Chemis

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A series of Zn (II), Pd (II) and Cd (II) complexes, [(L)nMX2]m (L = L‐a–L‐c; M = Zn, Pd; X = Cl; M = Cd; X = Br; n, m = 1 or 2), containing 4‐methoxy‐N‐(pyridin‐2‐ylmethylene) aniline (L‐a), 4‐methoxy‐N‐(pyridin‐2‐ylmethyl) aniline (L‐b) and 4‐methoxy‐N‐methyl‐N‐(pyridin‐2‐ylmethyl) aniline (L‐c) have been synthesized and characterized. The X‐ray crystal structures of Pd (II) complexes [L1PdCl2] (L = L‐b and L‐c) revealed distorted square planar geometries obtained via coordinative interaction of the nitrogen atoms of pyridine and amine moieties and two chloro ligands. The geometry around Zn (II) center in [(L‐a)ZnCl2] and [(L‐c)ZnCl2] can be best described as distorted tetrahedral, whereas [(L‐b)2ZnCl2] and [(L‐b)2CdBr2] achieved 6‐coordinated octahedral geometries around Zn and Cd centers through 2‐equivalent ligands, respectively. In addition, a dimeric [(L‐c)Cd(μ‐Br)Br]2 complex exhibited typical 5‐coordinated trigonal bipyramidal geometry around Cd center. The polymerization of methyl methacrylate in the presence of modified methylaluminoxane was evaluated by all the synthesized complexes at 60°C. Among these complexes, [(L‐b)PdCl2] showed the highest catalytic activity [3.80 × 104 g poly (methyl methacrylate) (PMMA)/mol Pd hr−1], yielding high molecular weight (9.12 × 105 g mol−1) PMMA. Syndio‐enriched PMMA (characterized using 1H‐NMR spectroscopy) of about 0.68 was obtained with Tg in the range 120–128°C. Unlike imine and amine moieties, the introduction of N‐methyl moiety has an adverse effect on the catalytic activity, but the syndiotacticity remained unaffected.

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Section: Introductionmentioning

confidence: 99%

Zinc (II), palladium (II) and cadmium (II) complexes containing 4‐methoxy‐N‐(pyridin‐2‐ylmethylene) aniline derivatives: Synthesis, characterization and methyl methacrylate polymerization

Park

Lee

et al. 2019

Applied Organom Chemis

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“…Besides many useful applications such as storage, separation, catalysis, and so on, porous materials may also serve as nano-reactors to control the molecular structures and morphologies of the products by restricting the space around the guest reactants/products, and even form host-guest nanocomposites with interesting properties 1 2 3 . Compared with the conventional bulk reactions, the structrues, molecular weights and stereoregularity of polymer products obtained in porous hosts 4 , especially periodic/crystalline ones with microporous channels 5 6 7 , can be regulated to much higher levels. When the reactant and products are both small molecules, organic reactions such as Diels-Alder addition 8 , isomerization 9 and photodimerization 10 can be more rationally controlled 11 , because the guest molecules can fit the periodicity of the pore environment to enable good host-guest matching 12 .…”

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confidence: 99%

Coordination templated [2+2+2] cyclotrimerization in a porous coordination framework

et al. 2015

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Controlling chemical reactions by the supramolecular confinement effects of nanopores has attracted great attention. Here we show that open metal sites in porous coordination frameworks can constitute more powerful and strict templates for precision syntheses. A Fe(III) dicarboxylate framework functionalized with triangularly arranged metal sites is used to accomplish [2+2+2] cyclotrimerization reactions for organonitrile, alkyne and alkene monomers bearing a geometrically suitable pyridyl group. In situ single-crystal X-ray diffraction facilitates the direct observation of such a coordination templated reaction, before cylcotrimerization, the monomer coordinates at the Fe(III) centre by its pyridyl donor, which forces three unsaturated groups to gather around a position very similar with that of the desired covalent cyclic trimer. After the reaction, the trimers serve as tripodal ligands to perfectly fix the Fe(III) ions and the whole crystal to generate an exceptionally rigid and porous material with large surface area coupled with guest-proof zero thermal expansion.

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“…12 In these frameworks, the unsaturated sites are located at the corners of the hexagonalshaped channels. 13 We found that the polymerization behaviors are strongly dependent on the Lewis acidity of the metal sites.…”

Section: ¹1mentioning

confidence: 99%

Polymer Synthesis in Coordination Nanospaces

Uemura¹

2011

Bulletin of the Chemical Society of Japan

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In nature, biopolymers are efficiently synthesized by multilevel arrangements of monomers within constrained molecular-level spaces. These biological systems produce regio-and stereoregular polymers with uniform molecular weights, and can also arrange the higher order structures of the resulting polymers. Inspired by the elegant operations of polymerization in biological systems, polymer synthesis in artificial confined geometries is a promising strategy for the control of polymer primary structures and the design of well-defined nanostructures. Recently, we have established a new methodology for controlling polymer synthesis using microporous coordination compounds. In this account, recent progress and future perspectives of polymerizations in these coordination nanospaces are reviewed.

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Effects of Unsaturated Metal Sites on Radical Vinyl Polymerization in Coordination Nanochannels

Cited by 39 publications

References 48 publications

Zinc (II), palladium (II) and cadmium (II) complexes containing 4‐methoxy‐N‐(pyridin‐2‐ylmethylene) aniline derivatives: Synthesis, characterization and methyl methacrylate polymerization

Zinc (II), palladium (II) and cadmium (II) complexes containing 4‐methoxy‐N‐(pyridin‐2‐ylmethylene) aniline derivatives: Synthesis, characterization and methyl methacrylate polymerization

Coordination templated [2+2+2] cyclotrimerization in a porous coordination framework

Polymer Synthesis in Coordination Nanospaces

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