Journal of Polymer Science Part A: Polymer Chemistry

Cover image for Vol. 44 Issue 17

Special Issue: 2005 USA-Japan Forum: “Advances in Polymer Chemistry and Their Impacts upon Society”

1 September 2006

Volume 44, Issue 17

Pages i–ii, 4939–5236

Issue edited by: Karen L. Wooley

  1. Foreword

    1. Top of page
    2. Foreword
    3. Articles
    4. Highlights
    5. Articles
    6. Highlights
    7. Articles
    1. You have free access to this content
      Foreword (pages i–ii)

      Toshio Masuda and Karen L. Wooley

      Version of Record online: 27 JUL 2006 | DOI: 10.1002/pola.21696

  2. Articles

    1. Top of page
    2. Foreword
    3. Articles
    4. Highlights
    5. Articles
    6. Highlights
    7. Articles
    1. Amphiphilic diblock star polymer catalysts via atom transfer radical polymerization (pages 4939–4951)

      William R. Dichtel, Kyung-Youl Baek, Jean M. J. Fréchet, Ivo B. Rietveld and Sergei A. Vinogradov

      Version of Record online: 18 JUL 2006 | DOI: 10.1002/pola.21610

      Thumbnail image of graphical abstract

      Well defined diblock star polymers containing Pd porphyrin cores were synthesized via atom transfer radical polymerization. The star polymers contained a hydrophobic interior microenvironment and a hydrophilic exterior, a design intended to favor concentration of non-polar substrates in the vicinity of the photosensitizer core. The star polymers showed enhanced reactivity in the photooxidation of 2-furaldehyde relative to a small molecule porphyrin control, suggesting that the polymer backbone aids with catalytic turnover. Oxygen diffusion studies indicate that the polymer backbone shields the porphyrin excited state from oxygen quenching, though this effect is not pronounced enough to retard the rate of singlet oxygen generation under preparative photooxidation conditions.

    2. Stereocontrol of diene polymers by topochemical polymerization of substituted benzyl muconates and their crystallization properties (pages 4952–4965)

      Akikazu Matsumoto, Daisuke Furukawa and Hideyuki Nakazawa

      Version of Record online: 18 JUL 2006 | DOI: 10.1002/pola.21600

      Thumbnail image of graphical abstract

      We report the stereocontrol of diene polymers by the topochemical polymerization of alkoxy-substituted benzyl muconates in the solid state. The translational and alternating types of molecular stacking structures in a column provide diisotactic and disyndiotactic polymers, respectively, by the solid-state polymerization. On the other hand, the meso and racemo structures of the resulting polymers are determined by the molecular symmetry of the used muconate monomers. The various substituted benzyl ester polymers are transformed into the same ethyl ester polymers with the four types of tacticities. The effects of the tacticity on their crystallization property of the stereoregular polymers have been revealed.

    3. Metal-complex-bearing star polymers by metal-catalyzed living radical polymerization: Synthesis and characterization of poly(methyl methacrylate) star polymers with Ru(II)-embedded microgel cores (pages 4966–4980)

      Takaya Terashima, Makoto Ouchi, Tsuyoshi Ando, Masami Kamigaito and Mitsuo Sawamoto

      Version of Record online: 21 JUL 2006 | DOI: 10.1002/pola.21597

      Thumbnail image of graphical abstract

      Ru(II)-bearing microgel star polymers were directly synthesized in high yields by the polymer-linking reaction of poly(methyl methacrylate)s with a divinyl compound and a phosphine ligand monomer in RuCl2(PPh3)3-catalyzed living radical polymerization, followed by an in situ ligand-exchange reaction between the phosphine ligands in the core and Ru(II) polymerization catalysts; Ru entrapping was nearly quantitative (3.1–7.4 ×10−5 mol of Ru/g of polymer). The star polymers were characterized as follows: an absolute molecular weight of 1.7 × 105 to 1.7 × 106, an arm number of 11–92 arms/polymer, and a radius of gyration of 8–19 nm (in N,N-dimethylformamide). Direct observation of the star polymers was also achieved with transmission electron microscopy and atomic force microscopy.

    4. Precision branching in ethylene copolymers: Synthesis and thermal behavior (pages 4981–4989)

      Erik B. Berda, Travis W. Baughman and Kenneth B. Wagener

      Version of Record online: 21 JUL 2006 | DOI: 10.1002/pola.21603

      Thumbnail image of graphical abstract

      Polyethylene and ethylene-based copolymers are the world's most widely produced macromolecules. Chain-propagation chemistry is generally used to produce these materials, during which undesirable chain-transfer or chain-walking side reactions incorporate small fractions of structural imperfections into the polymer microstructure. Acyclic diene metathesis polymerization allows the synthesis of sequenced polyethylene copolymers via step-growth propagation, thereby avoiding the inherent side reactions associated with chain polymerization.

    5. A variety of poly(m-benzamide)s with low polydispersities from inductive effect-assisted chain-growth polycondensation (pages 4990–5003)

      Tomoyuki Ohishi, Ryuji Sugi, Akihiro Yokoyama and Tsutomu Yokozawa

      Version of Record online: 21 JUL 2006 | DOI: 10.1002/pola.21616

      Thumbnail image of graphical abstract

      m-(Alkylamino)benzoic acid alkyl esters 1 underwent chain-growth polycondensation by virtue of the different inductive effects between monomer and polymer to yield a variety of well-defined poly(m-benzamide)s, including an N-unsubstituted one. All these polymers obtained showed higher solubility in organic solvents than the para-counterparts.

    6. Well-defined polymers with acetal side chains as reactive scaffolds synthesized by atom transfer radical polymerization (pages 5004–5013)

      Ronald C. Li, Rebecca M. Broyer and Heather D. Maynard

      Version of Record online: 21 JUL 2006 | DOI: 10.1002/pola.21609

      Thumbnail image of graphical abstract

      Well-defined poly(3,3′-diethoxypropyl methacrylate), (PDEPMA) was prepared by atom transfer radical polymerization (ATRP) using ethyl 2-bromoisobutyrate and CuBr/2,2′-bipyridine (BIPY) in methanol at 21 °C. Different molecular weights and narrow molecular weight distributions (PDIs < 1.3) were obtained. To demonstrate the suitability of using this polymer as a reactive scaffold, the polymer side chains were hydrolyzed to aldehydes. Aminooxy-functionalized oligo(ethylene glycol) and O-(carboxymethyl)hydroxylamine were conjugated to the side chains forming oxime linkages.

    7. Enzyme-catalyzed synthesis of natural and unnatural polysaccharides (pages 5014–5027)

      Masashi Ohmae, Shun-Ichi Fujikawa, Hirofumi Ochiai and Shiro Kobayashi

      Version of Record online: 21 JUL 2006 | DOI: 10.1002/pola.21599

      Thumbnail image of graphical abstract

      On the basis of the concept “transition-state analogue substrate”, synthesis of hyaluronan (HA), chondroitin (Ch), and their derivatives was achieved via “enzymatic polymerization”. The oxazoline derivatives of N-acetylhyalobiuronate (1a) and N-acetylchondrosine (2a) were polymerized by hyaluronidase, giving rise to synthetic HA (3a) and Ch (4a). The enzyme also produced some kinds of N-acyl HAs (3b3d) and Chs (4b, 4c) derivatives from 2-substituted oxazolines (1b1d) and (2b, 2c). Furthermore, the sulfated monomer (5a) was catalyzed and polymerized by hyaluronidase, providing the corresponding polymer (6a).

    8. Synthesis, properties, and gas permeability of novel poly(diarylacetylene) derivatives (pages 5028–5038)

      Toshikazu Sakaguchi, Kenichi Yumoto, Yuichi Shida, Masashi Shiotsuki, Fumio Sanda and Toshio Masuda

      Version of Record online: 21 JUL 2006 | DOI: 10.1002/pola.21622

      Thumbnail image of graphical abstract

      Poly(diphenylacetylene)s having various silyl groups are soluble in common solvents, from whose membranes solvent-insoluble poly(diphenylacetylene) membranes can be obtained by desilylation. The oxygen permeability coefficients of the desilylated polymers are quite different from one another (120–3300 barrers) irrespective of the same polymer structure. Poly(diphenylacetylene)s having t-butyldimethylsiloxy groups polymerizes into high-molecular-weight polymers. These polymers are soluble in common organic solvents to provide free-standing membranes. Desilylation of these membranes yields poly(diphenylacetylene)s having free hydroxyl groups, which is the first example of poly(diphenylacetylene)s carrying highly polar groups.

    9. Chirality sensing of various biomolecules with helical poly(phenylacetylene)s bearing acidic functional groups in water (pages 5039–5048)

      Hisanari Onouchi, Takashi Hasegawa, Daisuke Kashiwagi, Hiroyuki Ishiguro, Katsuhiro Maeda and Eiji Yashima

      Version of Record online: 21 JUL 2006 | DOI: 10.1002/pola.21621

      Thumbnail image of graphical abstract

      Helicity induction on poly(phenylacetylene)s bearing acidic functional groups, such as phosphonic acid and its monoethyl ester, carboxylic acid, and sulfonic acid residues, with various biomolecules, such as peptides, amino sugars, and carbohydrates, was investigated in water. The polymers with strongly acidic groups such as a phosphonic acid and a sulfonic acid could efficiently interact with biomolecules and formed a predominantly one-handed helix. The complexes exhibited characteristic induced circular dichroisms in the ultraviolet–visible regions. On the other hand, a polymer with a weak carboxylic acid showed induced circular dichroisms only in the presence of carbohydrates and some proteins.

    10. Effect of stoichiometry on liquid crystalline supramolecular polymers formed with complementary nucleobase pair interactions (pages 5049–5059)

      Kelly A. Burke, Sona Sivakova, Blayne M. McKenzie, Patrick T. Mather and Stuart J. Rowan

      Version of Record online: 27 JUL 2006 | DOI: 10.1002/pola.21626

      Thumbnail image of graphical abstract

      Liquid crystalline polymeric systems can be obtained through the use of complementary single nucleobase interactions. The effect of stoichiometry of the two components, as well as the thermal history of the materials on their liquid crystalline behavior, is investigated.

    11. Weak noncovalent Si···F[BOND]C interactions stabilized fluoroalkylated rod-like polysilanes as ultrasensitive chemosensors (pages 5060–5075)

      Anubhav Saxena, Roopali Rai, Sun-Young Kim, Michiya Fujiki, Masanobu Naito, Kento Okoshi and Giseop Kwak

      Version of Record online: 28 JUL 2006 | DOI: 10.1002/pola.21607

      Thumbnail image of graphical abstract

      Noncovalent interactions, such as hydrogen bonding, metal coordination, and π-π stacking, are increasingly being utilized to develop well-ordered and self-organized supramolecular materials. Recently, new types of nonclassical weak interactions, such as C[BOND]H···π, C[BOND]H···F[BOND]C, and C[BOND]H···O, have been exploited in stabilizing the specific conformations of molecules and molecular assemblies in the solid state. These noncovalent interactions play an important role in materials comprised of polymer chains, because cooperative effects from a large number of weak interactions can lead to drastic changes in its conformation, several properties, and functionalities. The programmed design of synthetic helical polymer with well-defined molecular conformation has been the main subject in modern polymer science and engineering. Silicon-catenated polysilane is an ideal helical silicon quantum wire and polymers with unique photophysical properties. The present review highlights the spectroscopic evidences for through-space weak Si···F[BOND]C interaction in poly(methyl-3,3,3-trifluoropropylsilane) (1) in noncoordinating and coordinating solvents by means of NMR (29Si and 19F) and IR spectroscopies, and viscometric measurement. It was found that 1 is applicable for chemosensors with an extremely high sensitivity and selectivity toward fluoride ions in tetrahydrofuran (THF) and with high sensitivity for nitroaromatic compounds, detected by a decrease in the photoluminescence intensity in THF and in thin solid film.

  3. Highlights

    1. Top of page
    2. Foreword
    3. Articles
    4. Highlights
    5. Articles
    6. Highlights
    7. Articles
    1. You have free access to this content
      Functionalization of nanoparticles for dispersion in polymers and assembly in fluids (pages 5076–5086)

      Elizabeth Glogowski, Ravisubhash Tangirala, Thomas P. Russell and Todd Emrick

      Version of Record online: 28 JUL 2006 | DOI: 10.1002/pola.21598

      Thumbnail image of graphical abstract

      The fluorescent, magnetic, and conductive properties of nanoparticles can transform polymer-based materials into composites with higher levels of sophistication than found in polymers alone. The ligand chemistry of nanoparticles is critically important in the development of polymer–nanoparticle composites to prevent nanoparticle aggregation and direct their assembly within polymers. Nanoparticle ligands can also prevent aggregation in solution and direct the assembly of nanoparticles at fluid–fluid interfaces, that interfacial chemistries can be performed to provide new routes to ultrathin composite sheets and capsules.

  4. Articles

    1. Top of page
    2. Foreword
    3. Articles
    4. Highlights
    5. Articles
    6. Highlights
    7. Articles
    1. Preparation of HPLC chiral packing materials using cellulose tris(4-methylbenzoate) for the separation of chrysanthemate isomers (pages 5087–5097)

      Chiyo Yamamoto, Kenji Yamada, Kahori Motoya, Yuichiro Kamiya, Masami Kamigaito, Yoshio Okamoto and Tadatoshi Aratani

      Version of Record online: 28 JUL 2006 | DOI: 10.1002/pola.21620

      Thumbnail image of graphical abstract

      The chiral recognition ability of cellulose tris(4-methylbenzoate) (2a) coated on silica gel significantly depends on the preparation conditions of the chiral packing material (CPM). The CPMs 2a prepared with methyl benzoate or acetophenone as an additive show a high chiral recognition for chrysanthemic acid ethyl ester (1a) as a target molecule, and the imprinted CPM was stable for a long time at room temperature. The improvement of chiral recognition ability for 1a may be attributed to the change of the higher ordered structure of 2a by imprinting additives.

    2. Environmentally benign atom transfer radical polymerization: Towards “green” processes and materials (pages 5098–5112)

      Nicolay V. Tsarevsky and Krzysztof Matyjaszewski

      Version of Record online: 28 JUL 2006 | DOI: 10.1002/pola.21617

      Thumbnail image of graphical abstract

      Several major environmental aspects of atom transfer radical polymerization (ATRP) are reviewed, including (i) methods for catalyst removal, (ii) development of active ATRP catalysts, (iii) conducting ATRP in environmentally friendly media (water, supercritical cabon dioxide, and ionic liquids, and (iv) application of ATRP to the production of advanced materials such as self-plasticized poly(vinyl chloride) and (bio)degradable polymers.

    3. Supramolecular polymers based on cyclodextrins (pages 5113–5119)

      Akira Harada

      Version of Record online: 28 JUL 2006 | DOI: 10.1002/pola.21618

      Thumbnail image of graphical abstract

      Two types of supramolecular polymers based on cyclodextrins were prepared. One was a host–guest type, and the other was a polyrotaxane type. When a guest part was covalently attached to cyclodextrin, they formed supramolecular dimers, a cyclic daisy chain, supramolecular oligomers, and polymers. t-Boc-cinnamoyl-β-cyclodextrin was found to form chiral supramolecular polymers in aqueous solutions. Supramolecular poly[2]rotaxane polymers and supramolecular α,β-cyclodextrin copolymers were obtained. Polyrotaxanes containing β-cyclodextrin or γ-cyclodextrin were prepared.

    4. Self-assembled graphitic nanotubes from an amphiphilic hexabenzocoronene bearing thiol functionalities: Redox-mediated polymerization and depolymerization (pages 5120–5127)

      Jin Motoyanagi, Takanori Fukushima, Atsuko Kosaka, Noriyuki Ishii and Takuzo Aida

      Version of Record online: 28 JUL 2006 | DOI: 10.1002/pola.21615

      Thumbnail image of graphical abstract

      A Gemini-shaped hexabenzocoronene amphiphile, 2,5-bis (4′-{2-[2-(2-thioacetylethoxy)ethoxy]ethoxy}phenyl)-11,14-didodecyl-hexa-peri-hexabenzocoronene (3), bearing a thioacetyl terminus at each hydrophilic oxyethylene chain self-assembled in tetrahydrofuran to form a nanotubular object with a uni form diameter of 20 nm and a wall thickness of 3 nm. The alkaline-mediated deprotection of the thiol functionalities, followed by autoxidation, resulted in the formation of a sur face-polymerized nanotube, which was rather tolerant against solvolysis. The reductive cleavage of the resulting disulfide linkages with dithiothreitol allowed the release of a thiol-appended amphiphilic hexabenzocoronene monomer (4) from the tubular assembly.

    5. In situ generation of nitroxide from alkoxyamines for controlled acrylate polymerization (pages 5128–5136)

      Qing Xia and Robert B. Grubbs

      Version of Record online: 28 JUL 2006 | DOI: 10.1002/pola.21605

      Thumbnail image of graphical abstract

      A general strategy for the controlled nitroxide-mediated polymerization of acrylates from alkoxyamines without addition of excess free nitroxide is outlined. 2,2-Dimethyl-3-(1-phenylethoxy)-4-phenyl-3-azapentane (1), prepared in one pot by the addition of 1-phenylethyl radicals to 2-methyl-2-nitrosopropane, is heated prior to the addition of monomer to afford a mixture of alkoxyamine 1, free nitroxide, and 2,3-diphenylbutane. This mixture is effective for controlling the polymerization of n-butyl acrylate.

    6. Self-assembled lipid nanotube hosts: The dimension control for encapsulation of nanometer-scale guest substances (pages 5137–5152)

      Toshimi Shimizu

      Version of Record online: 28 JUL 2006 | DOI: 10.1002/pola.21619

      Thumbnail image of graphical abstract

      Supramolecular nanotube hosts with precisely controlled inner or outer diameters have been synthesized by self-assembly of unsymmetrical bolaamphiphilic monomers or glucopyranosylamide lipids, respectively. Properties of water confined in the hollow cylinder of a glycolipid are discussed in comparison with those of bulk water. Recent progress in encapsulation of nanoscale objects, including gold or silver nanoparticles, ferritin, or magnetic crystals, into the hollow cylinder of the nanotube hosts is briefly reviewed. The dimension control of the nanotubes and their applications are also discussed.

    7. Assembled structures of nanocrystals in polymer/calcium carbonate thin-film composites formed by the cooperation of chitosan and poly(aspartate) (pages 5153–5160)

      Ayae Sugawara, Akira Oichi, Hiroko Suzuki, Yuzo Shigesato, Toshihiro Kogure and Takashi Kato

      Version of Record online: 28 JUL 2006 | DOI: 10.1002/pola.21604

      Thumbnail image of graphical abstract

      The biomimetic crystallization of calcium carbonate with chitosan and poly(aspartate) results in the formation of nanostructured hybrid composite films composed of aragonite and vaterite nanocrystals. The aragonite disklike films display radial orientation of the c axes. Vaterite disks show two different kinds of orientations: radial orientation and unusual rhythmic orientation such that the c axes are alternately aligned perpendicularly and parallel to the radial direction of the disk.

    8. Erosion of multilayered films fabricated from degradable polyamines: Characterization and evidence in support of a mechanism that involves polymer hydrolysis (pages 5161–5173)

      Jingtao Zhang, Nathaniel J. Fredin and David M. Lynn

      Version of Record online: 28 JUL 2006 | DOI: 10.1002/pola.21613

      Thumbnail image of graphical abstract

      Multilayered polyelectrolyte assemblies fabricated with hydrolytically degradable poly(amino ester)s erode gradually in physiological media. Here we investigated the role of polymer hydrolysis in governing film erosion. Characterization using reflective infrared spectroscopy demonstrated changes consistent with polymer hydrolysis, and assemblies fabricated with a poly(amino amide) did not erode under similar conditions. Additional experiments using a deuterated buffer were consistent with a mechanism of erosion in which polymer hydrolysis plays a significant role. These results, when combined, provide support for the view that polymer hydrolysis plays an important role in the erosion of polyelec trolyte assemblies fabricated from degradable polyamines.

  5. Highlights

    1. Top of page
    2. Foreword
    3. Articles
    4. Highlights
    5. Articles
    6. Highlights
    7. Articles
    1. You have free access to this content
      Synthesis and properties of organic-silica nanocomposites with perhydropolysilazane (pages 5174–5181)

      Reiko Saito

      Version of Record online: 28 JUL 2006 | DOI: 10.1002/pola.21612

      Thumbnail image of graphical abstract

      The synthesis and properties of the organic polymer-silica nanocomposites by blending perhydropolysilazane with organic polymer having hydroxyl groups have been described. Poly(methyl methacrylate) (PMMA)-silica nanocomposites with a PMMA/silica lamellar structure and spherical silica domains in a PMMA matrix were obtained with random copolymers and block copolymers. The effect of the architecture of the random and block copolymers on the morphology of composites has been summarized. The thermal stability, electrical properties, such as field break down, leakage current, etc., and surface hardness of the composites have been discussed.

  6. Articles

    1. Top of page
    2. Foreword
    3. Articles
    4. Highlights
    5. Articles
    6. Highlights
    7. Articles
    1. Alternating copolymerization of propylene oxide and carbon dioxide with highly efficient and selective (salen)Co(III) catalysts: Effect of ligand and cocatalyst variation (pages 5182–5191)

      Claire T. Cohen and Geoffrey W. Coates

      Version of Record online: 28 JUL 2006 | DOI: 10.1002/pola.21606

      Thumbnail image of graphical abstract

      Salen-based (salen = N,N′-bis(salicylidene)-1,2-diaminoalkane) cobalt catalysts for the alternating copolymerization of propylene oxide and CO2 provide a viable route to regioregular poly(propylene carbonate) without formation of propylene carbonate byproduct. The structural properties of the salen ligand in these catalysts and the inclusion organic-based ionic and Lewis-basic cocatalysts dictate the copolymerization activity and regioselectivity. Once optimized, catalyst turnover frequencies up to 720 h−1 for propylene oxide/CO2 copolymerization were observed for the generation of regioregular poly(propylene carbonate).

    2. Supramolecular control of spin-crossover phenomena in lipophilic Fe(II)-1,2,4-triazole complexes (pages 5192–5202)

      Keita Kuroiwa, Tomoko Shibata, Sono Sasaki, Masaaki Ohba, Atsushi Takahara, Toyoki Kunitake and Nobuo Kimizuka

      Version of Record online: 28 JUL 2006 | DOI: 10.1002/pola.21601

      Thumbnail image of graphical abstract

      The spin-crossover properties of lipophilic Fe(II) tris-μ-triazole complexes were investigated in chloroform and cast films. The linear Fe(II) complex provided adaptable molecular clefts, and the cocasting of equimolar tetradecanol produced composite films in which alcohol molecules were bound to the complex by ionic hydrogen bonding (ROH···Cl) and van der Waals interactions. They showed a reversible abrupt spin crossover accompanied by thermal hysteresis, and the observed bistability was related to dynamic structural transformations between lamellar and hexagonal structures. This study provides a novel supramolecular approach to designing spin-crossover polymer films with controlled thermal bistability.

    3. Facile syntheses of surface-functionalized micelles and shell cross-linked nanoparticles (pages 5203–5217)

      Rachel K. O'Reilly, Maisie J. Joralemon, Craig J. Hawker and Karen L. Wooley

      Version of Record online: 28 JUL 2006 | DOI: 10.1002/pola.21602

      Thumbnail image of graphical abstract

      Block copolymer micelles were assembled from amphiphilic block copolymers, bearing Click-reactive chemical functionality uniquely at the chain terminus of the hydrophilic block segment, and then transformed into shell cross-linked nanoparticles. Four nanostructures resulted each presenting alkynyl or azido Click functionality from its surface.

    4. Influence of the structure of nanoscopic building blocks on the assembly of micropatterned surfaces (pages 5218–5228)

      David S. Germack, Simon Harrisson, Gerald O. Brown and Karen L. Wooley

      Version of Record online: 28 JUL 2006 | DOI: 10.1002/pola.21614

      Thumbnail image of graphical abstract

      An amphiphilic diblock copolymer, having one block segment composed of isoprene repeat units and another composed of alternating maleic anhydride and styrene units, produced micropatterned surfaces when preassembled into nanoscopic objects in solution and then deposited onto a substrate. This article details the employment of reversible addition–fragmentation chain transfer polymerization for the preparation of the diblock copolymer and detailed studies of the conditions required to establish the micropatterns.

    5. Synergetic activation of carbon dioxide molecule using phenylazomethine dendrimers as a catalyst (pages 5229–5236)

      Takane Imaoka, Reiko Tanaka and Kimihisa Yamamoto

      Version of Record online: 28 JUL 2006 | DOI: 10.1002/pola.21611

      Thumbnail image of graphical abstract

      Metal-assembling phenylazomethine dendrimers (with lanthanide cations) that have a cobalt porphyrin core act as a unique catalyst for CO2 reduction with a very low overpotential (negative potential). One of the reasons for the excellent property in the CO2 activation is multi-electron transfer process by poly-metallic structure in the dendrimers. We compared the catalytic activity by generation number and topology of the dendrimer. The bis-substituted G4 (generation 4) one at neighboring meso positions on the cobalt porphyrin ring showed the best performance in the catalytic activity. This suggests a synergistic effect between the metal-assembling dendrons and the cobalt porphyrin core as a catalytic center.

SEARCH

SEARCH BY CITATION