Ring‐opening metathesis copolymerization of cyclooctene and a carborane‐containing oxanorbornene

The incorporation of a silyl‐protected oxanorbornene imide carborane (SONIC) in polyethylene‐like materials is reported. These copolymers were obtained via ring‐opening metathesis copolymerization of (SONIC) and cyclooctene followed by hydrogenation with p‐toluenesulfonylhydrazide. The composition of the copolymer was varied by altering the feed ratio. Structural and thermal properties were investigated and compared with that of a model polymer so as to gauge the impact on the inclusion of the silyl‐functionalized carborane. An initial observation of the modification of the chain sequence upon changing solvent polarity is also discussed. Finally, the potential utilization of these materials as radiation shielding materials is mentioned. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2557–2563, 2010     

Ring‐opening metathesis polymerization of cyclododecene using an electrochemically reduced tungsten‐based catalyst

The ring‐opening metathesis polymerization of cyclododecene using an electrochemically reduced tungsten‐based catalyst (WCl₆? e^?? Al? CH₂Cl₂) is described. In addition, the influence of reaction conditions on the polymerization yield was determined. The resulting polymer has been characterized by NMR, IR, gel permeation chromatography and differential scanning calorimetry. The glass transition temperature and melting point of the polydodecenamer are 19.6°C and 70.0°C respectively. Furthermore, cyclododecene has been polymerized into a low‐molecular‐weight polymer (12.0 × 10³) with a polydispersity of 2.06 in high yields (94%). IR and NMR analysis indicate that the polydodecenamer has a high trans content (60%). Copyright © 2004 John Wiley & Sons, Ltd.     

Enantioseparation of doubly functionalized polar norbornenes by HPLC and their ruthenium‐catalyzed ring‐opening metathesis polymerization

Doubly fuctionalized polar norbornenes bearing the cyano and ester groups in 2,3‐positions are synthesized and enantiomers are separated by high performance liquid chromatography (HPLC) with a chiral stationary phase. These optically active monomers are polymerized by ruthenium carbene catalysts, and high yields of the polymers were obtained. The chiral monomer bearing ethyl ester gave an optically active polymer of lower, but opposite sign of optical rotation (monomer [α]_D = +61.0°, polymer [α]_D = ?3.1°). The circular dichroism (CD) of the obtained chiral polymers gave a Cotton effect. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 485–491, 2010     

Ring‐opening metathesis polymerization of new norbornene‐based monomers containing various chromophores

Pure exo‐functional norbornene monomers containing various chromophores such as fluorene, pyrene, and carbazole were successfully prepared via the Diels–Alder reaction and condensation reaction. The living ring‐opening metathesis polymerization (ROMP) of a fluorene‐containing monomer, exo‐2‐(fluorene‐9‐ylcarboxymethyl)norborn‐5‐ene (exo‐1), was observed and confirmed by the formation of a diblock copolymer and a linear relationship between the number‐average molecular weight and [M]/[I] ratios ([M] = monomer concentration; [I] = initiator concentration). The synthesis and characteristics of novel fluorene‐containing polymers based on pure exo‐1 are reported with Grubbs catalyst I {RuCl₂(CHPh)[P(C₆H₁₁)₃]₂} with a high molecular weight of 3.18 × 10⁴ in 90 s ([M]/[I] = 100). However, the ROMP of pyrene‐ and carbazole‐containing monomers [exo‐5‐(pyrene methoxy carbonyl)bicyclo[2.2.1]hept‐2‐ene and exo‐5‐(carbazole ethoxy carbonyl)bicyclo[2.2.1]hept‐2‐ene, respectively] were carried out in a nonliving fashion. All the chromophore‐containing polymers showed excellent solubility in various organic solvents, particularly in chloroform, N‐methyl‐2‐pyrrolidinone, and 1,2‐dichlorobenzene. The glass transition temperatures of polynorbornenes containing various chromophores were determined to be 80–109 °C (by differential scanning calorimetry) higher than that of ring‐opened polynorbornene (glass transition temperature = 35 °C), indicating that the incorporation of the pendant aromatic moieties (e.g., fluorene, pyrene, and carbazole) could enhance the transition temperature for segmental motions of polymer chains. The photoluminescence spectra of all polymer solutions showed a strong emission in the blue region of the visible spectra. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3022–3031, 2007     

Ring‐opening metathesis polymerization of fatty acid derived monomers

The ring‐opening metathesis polymerization (ROMP) of fatty acid functionalized norbornenes was explored in the presence of dichloro[1,3‐bis(2,4,6‐trimethylphenyl)‐2‐imidazolidinylidene](benzylidene)bis(3‐bromopyridine)ruthenium(II) ( C3 ) at room temperature. The investigated monomers were derived from fatty acids with different chain lengths (C₆, C₈, C₁₀, C₁₂, C₁₄, C₁₆, and C₁₈) and can therefore contribute to the development of more sustainable, bio‐based polymeric materials. The polymerizations initiated by C3 proceeded in a living fashion with good initiation efficiency, and thus the synthesis of well‐defined polymers with narrow polydispersities was accomplished. All prepared polymers were fully characterized (GPC, DSC, TGA, NMR) and the results of these investigations are discussed within this contribution. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Ring‐opening metathesis polymerization of amino acid‐functionalized norbornene derivatives

Amino acid‐derived novel norbornene derivatives, N,N′‐(endo‐bicyclo[2.2.1] hept‐5‐en‐2,3‐diyldicarbonyl) bis‐L ‐alanine methyl ester (NBA), N,N′‐(endo‐bicyclo[2.2.1]hept‐5‐en‐2,3‐diyldicarbonyl) bis‐L ‐leucine methyl ester (NBL), N,N′‐(endo‐bicyclo[2.2.1]hept‐5‐en‐2,3‐diyldicarbonyl) bis‐L ‐phenylalanine methyl ester (NBF) were synthesized and polymerized using the Grubbs 2nd generation ruthenium (Ru) catalyst. Although NBA, NBL, and NBF did not undergo homopolymerization, they underwent copolymerization with norbornene (NB) to give the copolymers with M_n ranging from 5200 to 38,100. The maximum incorporation ratio of the amino acid‐based unit was 9%, and the cis contents of the main chain were 54–66%. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5337–5343, 2006     

Kinetics of the ring‐opening metathesis polymerization of a 7‐oxanorbornene derivative by Grubbs' catalyst

The kinetics of the initiation and propagation of the ring‐opening metathesis polymerization of exo,exo‐5,6‐bis(methoxycarbonyl)‐7‐oxabicyclo[2.2.1]hept‐2‐ene catalyzed by Grubbs' catalyst (Cl₂(PCy₃)₂Ru?CHPh) were measured by ultraviolet–visible and ¹H NMR spectroscopy, respectively. Activation parameters for these processes were also determined. Although the ratio of the rate constant of initiation to the rate constant of propagation was determined to be less than 1 for this system, this polymerization showed many of the characteristics of a living system, including low polydispersities. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2125–2131, 2003     

Charge‐transfer piperazine‐containing polymeric systems via ring‐opening metathesis polymerization

This article describes the synthesis of piperazine‐containing homopolymer systems via ring‐opening metathesis polymerization (ROMP). These systems were subsequently used as electron donors in the formation of charge‐transfer (CT) complexes. Using exo‐N‐(6‐bromohexyl)‐7‐oxabicyclo[2.2.1]hept‐5‐ene‐2,3‐dicarboxamide as a starting material, monomers were synthesized to act as electron donors. The amine group at the “open” end of the piperazine was either left open or alkylated with various alkyl groups. The monomers' ability to act as electron donors and their polymerization rates were studied. After initial photometric titration studies using 2,3‐dichloro‐5,6‐dicyanobenzoquinone (DDQ) as an electron acceptor proved that these monomers would act as electron donors, they were subsequently polymerized into homopolymers via ROMP. The experimental results showed that a methanol:chloroform mixed solvent system enhanced the rate of polymerization over a single solvent (chloroform) system. Studies also showed that the alkylated piperazine‐containing monomer had a faster rate of polymerization than the secondary piperazine monomer. These monomers were used to make piperazine‐containing homopolymers via ROMP and the resulting polymers, like the monomers, also functioned as electron donors. Potential functions of these polymers include electronics, solar cells, optical systems, and biological applications. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5034–5043, 2009     

Ring‐opening metathesis polymerization‐derived,lectin‐functionalized monolithic supports for affinity separation of glycoproteins

Lectin‐functionalized monolithic columns were prepared within polyether ether ketone (PEEK) columns (150 × 4.6 mm id) via transition metal‐catalyzed ring‐opening metathesis polymerization of norborn‐2‐ene (NBE) and trimethylolpropane‐tris(5‐norbornene‐2‐carboxylate) (CL) using the first‐generation Grubbs initiator RuCl₂(PCy₃)₂(CHPh) (1, Cy = cyclohexyl) in the presence of a macro‐ and microporogen, i.e. of 2‐propanol and toluene. Postsynthesis functionalization was accomplished via in situ grafting of 2,5‐dioxopyrrolidin‐1‐yl‐bicyclo[2.2.1]hept‐5‐ene‐2‐carboxylate to the surface of the monoliths followed by reaction with α,ω‐diamino‐poly(ethyleneglycol). The pore structure of the poly(ethyleneglycol)‐ derivatized monoliths was investigated by electron microscopy and inverse‐size exclusion chromatography, respectively. The amino‐poly(ethyleneglycol) functionalized monolithic columns were then successfully used for the immobilization of lectin from Lens culinaris hemagglutinin. The thus prepared lectin‐functionalized monoliths were applied to the affinity chromatography‐based purification of glucose oxidase. The binding capacity of Lens culinaris hemagglutinin‐immobilized monolithic column for glucose oxidase was found to be 2.2 mg / column.     

Ring‐opening metathesis polymerization of a modified linseed oil with varying levels of crosslinking

A commercial norbornyl‐functionalized linseed oil, blended with a bicyclic norbornene‐based crosslinking agent (at loadings ranging from 0 to 50 wt %) undergoes ring‐opening metathesis polymerization with the 1st generation Grubbs' catalyst to form a biorenewable polymer network. Comonomers are characterized, the thermal and mechanical properties of the cured systems are investigated by dynamic mechanical analysis, and thermal decomposition is evaluated by thermogravimetric analysis. The resin is shown to consist of a modified linseed oil and small oligomers of cyclopentadiene. Broad tan δ peaks suggest inhomogeneous phase morphologies, which result in complex crosslinking behaviors. The thermal stability of the polymers increases with increasing crosslinker content. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6851–6860, 2008     

Synthesis of phenylenevinylene and naphthylenevinylene homopolymers and block copolymers by ring‐opening metathesis polymerization

Homopolymers and copolymers containing phenylenevinylenes and naphthylenevinylenes can be synthesized by ring‐opening metathesis polymerization of strained monomers such as tetraoctyloxy‐substituted cyclophanedienes and naphthalenophanedienes initiated by the third‐generation Grubbs’ initiator. The resulting homopolymers exhibited low polydispersities. The block copolymers can also be synthesized by the sequential ring‐opening metathesis polymerization of two individual monomers. The structures of homopolymers and block copolymers were fully characterized by nuclear magnetic resonance spectroscopy. The molecular weight distribution of the block copolymers is relatively broad compared to their parent homopolymers possibly due to chain transfer reaction. The molar ratio of the two blocks can be tailored by the ratio of the monomers employed. The block copolymers exhibited a more efficient energy transfer in the solid state between the different blocks than those carried out in solution. The optical and electrochemical properties of the polymers were investigated and exhibited the potential uses in optoelectronics devices. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 67–74     

Xanthene dye functionalized norbornenes for the use in ring opening metathesis polymerization

A convenient synthetic route towards polymerizable fluorescein, dicholorofluorescein, and eosin dyes is presented. Polymerizability was provided by linking 2‐norbornene carboxylic acid, 11‐bromo‐undecyl ester to the dye's carboxylate functionality. Although the monomers bearing dichlorofluorescein and eosin were obtained in high yield, the related fluorescein bearing monomer could only be obtained in low yield. In the latter case, concurring etherification and esterification led to a product mixture of the desired carboxy modified monomer and a double substituted by‐product. The dye‐monomers were used successfully for the preparation of statistical copolymers with endo,exo‐2,3‐norbornene dicarboxylic acid dimethylester by ROMP. Absorption and luminescence characteristics and, in particular, the acid/base sensitive behavior of the parent dyes were preserved in the monomers and copolymers. The absorption and emission maxima in THF solution and in the solid state were red shifted in comparison to the aqueous samples of the parent dyes. Dye‐copolymers exhibited good film forming properties. Solid state luminescence studies of the copolymers revealed an increasing sensitivity towards NEt₃ vapor in the order fluorescein < dichlorofluorescein < eosin bearing copolymer. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1336–1348, 2007     

Synthesis of thioether‐functional poly(olefin)s via ruthenium‐alkylidene initiated ring‐opening metathesis polymerization

Ring‐opening metathesis polymerization (ROMP) of thioether‐derived oxanorbornene imide ( M1 ) and its copolymerization with various cycloolefin comonomers such as cyclopentene ( M2 ), cyclopent‐3‐en‐1‐ol ( M3 ), cycloheptene ( M4 ), and cyclooctene ( M5 ) using Hoveyda–Grubbs second generation catalyst has been investigated. Polymerizations were performed at two different temperatures (0 and 25 °C) and the obtained functional poly(olefin)s were characterized by nuclear magnetic resonance ¹H and ¹³C (NMR), and infrared spectroscopy as well as size exclusion chromatography, differential scanning calorimetry, and thermogravimetric analysis analyses. Additionally, the dependence of the polymer composition on the reaction temperature and monomer feed was studied with time‐dependent ¹H NMR experiments. Copolymerization of M1 with a five‐membered cycloolefin monomer M2 showed relatively low ROMP reactivity irrespective of the reaction conditions in comparison to M3 , M4 , and M5 monomers. In general, the degree of monomer incorporation into poly(olefin)s were determined in the order of M5 > M3 > M4 > M2 , and that sheds light on the effect of cycloolefin ring strain energies in the ruthenium‐alkylidene initiated ROMP. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1741–1747     

Ruthenium‐based metathesis initiators: Development and use in ring‐opening metathesis polymerization

For many years, olefin metathesis has been a central topic of industrial and academic research because of its great synthetic utility. The employed initiators cover a wide range of compounds, from simple transition‐metal salts to highly sophisticated and well‐defined alkylidene complexes. Currently, ruthenium‐based catalysts are at the center of attention because of their remarkable tolerance toward oxygen, moisture, and numerous functionalities. This article focuses on recent developments in the field of ring‐opening metathesis polymerization using ruthenium‐based catalysts. ruthenium‐based initiators and their applications to the preparation of advanced polymeric materials are briefly reviewed. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2895–2916, 2002     

Copolymerization of amino acid and amino ester functionalized norbornenes via living ring‐opening metathesis polymerization

The block and random copolymerization of a series of amino acid and amino ester functionalized norbornenes by ring‐opening metathesis polymerization (ROMP) induced by the well‐defined molybdenum [Mo(?N‐2,6‐ⁱPr? C₆H₃)(?CHCMe₂)Ph)(OCMe₃)₂] or ruthenium [Ru(PCy)₂Cl₂(?CHPh)] based initiators is described. The monomers are derived from the amino acids glycine, alanine, and isoleucine or the methyl esters of these amino acids and either endo‐ or exo‐norborn‐5‐ene‐2,3‐dicarboxylic anhydride. Enantiomerically pure monomers afforded optically active polymers, and the mechanism and kinetics of the copolymerizations are investigated. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7985–7995, 2008     

Synthesis and self assembly of eosin functionalized amphiphilic block‐random copolymers prepared by ring opening metathesis polymerization

Self assembly of block copolymers has gained considerable attention because of its potential use in various areas such as medical and biomedical applications, nanotechnology, and electronics. Herein, we present the synthesis and characterization of amphiphilic block‐random copolymers with a covalently incorporated pH‐sensitive dye, namely eosin. Ring opening metathesis polymerization was chosen for the preparation of well defined block copolymers and block‐random copolymers using a modified “2nd Generation Grubbs” initiator. The self assembly behavior of the block‐random copolymers in solution was studied by dynamic light scattering and small angle X‐ray scattering (SAXS). The influence of dye incorporation on the result of the self assembly process in methanol and ethanol was investigated and a subtle interplay of the nature of the selective solvent, the chain‐length of the block copolymer and the position of the dye within the polymer chain was established. Structural investigations using SAXS revealed a spherical shape and a core‐shell structure of exemplary block and block‐random copolymer micelles. UV–vis absorption and photoluminescence measurements revealed similar optical properties for polymer micelles in methanol compared to polymer solutions in THF. The pH‐sensitive behavior of the eosin dye was preserved within the micelles. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 401–413, 2008     

Biofunctionalized block copolymer nanoparticles based on ring‐opening metathesis polymerization

We present an approach to the synthesis of biofunctionalized block copolymer nanoparticles based on ring‐opening metathesis polymerization; these nanoparticles may serve as novel scaffolds for the multivalent display of ligands. The nanoparticles are formed by the self‐assembly of diblock copolymers composed of a hydrophobic block and a hydrophilic activated block that can be functionalized with thiolated ligands in aqueous media. The activated block enables control over the orientation of the displayed ligands, which may be sugars, peptides, or proteins engineered to contain cysteine residues at suitable locations. The nanoparticle diameter can be varied over a wide range through changes in the composition of the block copolymer, and biofunctionalization of the nanoparticles has been demonstrated by the attachment of a peptide previously shown to inhibit the assembly of anthrax toxin. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 928–939, 2006     

Synthesis of reactive poly(norbornene): Ring‐opening metathesis polymerization of norbornene monomer bearing cyclic dithiocarbonate moiety

A norbornene monomer bearing cyclic dithiocarbonate moiety (NB‐DTC) was successfully synthesized from the corresponding precursor having epoxy moiety by its reaction with carbon disulfide. NB‐DTC underwent the ring‐opening metathesis polymerization (ROMP) catalyzed by a ruthenium carbene complex to give the corresponding poly(norbornene). The dithiocarbonate moiety incorporated into the side chain of the obtained poly(norbornene) reacted with amine to afford the corresponding thiourethane moiety with thiol group, which underwent oxidative S‐S coupling and/or addition reaction to the C‐C double bond in the main chain, leading to formation of a cross‐linked polymer. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011.