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Book Ring Opening Metathesis Polymerisation and Related Chemistry

Download or read book Ring Opening Metathesis Polymerisation and Related Chemistry written by Ezat Khosravi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the last ASI in Turkey in Sept. 1995, the olefin metathesis has made remarkable strong developments with an incredible speed in various directions. New catalyst systems have been developed which have resulted in the synthesis of novel materials. Other fascinating developments have been the new catalysts for stereoselective metathesis and catalysts with considerable functional group tolerance. These new catalysts in addition to Ring Opening Metathesis Polymerisation (ROMP) and Acyclic Diene Metathesis (ADMET) are now powerful tools for Ring Closing Metathesis (RCM) and have found many applications in the synthesis of natural products. A lot of information has been established about all aspects of the olefin metathesis and there is a vast literature concerning the process, covering the initiators, mechanistic features and applications of this reaction in organic and polymer synthesis. The NATO ASI on rd th ROMP and Related Chemistry took place in Polanica-Zdroj, Poland during 3 to 15 Sept. 2000, to highlight the developments in this area and to discuss the prospects and visions for the year 2000 and beyond. The aims of the ASI were: to provide a platform for dissemination of knowledge; to promote communication between people who have a serious interest in this field of chemistry; to help establishing international scientific contacts and to provide an opportunity for the scientists with an appropriate scientific background to learn of recent developments in this field of science. There were 15 lecturers and 67 participants in this NATO ASI.

Book Synthesis and Applications of Ring Opening Metathesis Polymerization Based Functional Block Copolymers

Download or read book Synthesis and Applications of Ring Opening Metathesis Polymerization Based Functional Block Copolymers written by Sanchita Biswas and published by . This book was released on 2010 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ring opening metathesis polymerization (ROMP) is established as one of the efficient controlled living polymerization methods which have various applications in polymer science and technology fields. The research presented in this dissertation addresses several applications of multifunctional well-defined norbornene-based block copolymers synthesized by ROMP using ruthenium-based Grubbs catalysts. These novel block copolymers were applied to stabilize maghemite nanoparticles, creating the superparamagnetic polymeric nanocomposites. The J-aggregation properties of the porphyrin dyes were improved via self-assembly with a customized norbornene polymer. Novel multimodal copolymer probes were synthesized for two-photon fluorescence integrin-targeted bioimaging. In Chapter 1 a brief overview of ROMP along with ruthenium metal catalysts and selected applications of the polymers related to this research is presented. Superparamagnetic maghemite nanoparticles are important in biotechnology fields, such as enhanced magnetic resonance imaging (MRI), magnetically controlled drug delivery, and biomimetics. However, cluster formation and eventual loss of nano-dimensions is a major obstacle for these materials. Chapter 2 presents a solution to this problem through nanoparticles stabiulized in a polymer matrix. The synthesis and chracterization of novel diblock copolymers, consisting of epoxy pendant anchoring groups to chelate maghemite nanoparticles and steric stabilizing groups, as well as generation of nanocomposites and their characterization, including surface morphologies and magnetic properties, is discussed in Chapter 2. In Chapter 3, further improvement of the nanocomposites by ligand modification and the synthesis of pyrazole-templated diblock copolymers and their impact to stabilize the maghemite nanocomposite are presented. Additionally, the organic soluble magnetic nanocomposites with high magnetizations were encapsulated in an amphiphilic copolymer and dispersed in water to assess their water stability by TEM. To gain a preliminary measure of biocopatibility of the micelle-encapsulated polymeric magnetic nanocomposites, cell-viability was determined. In Chapter 4, aggregation behaviors of two porphyrin-based dyes were investigated. A new amphiphilic homopolymer containing secondary amine moieties was synthesized and characterized. In low pH, the polymer became water soluble and initiated the stable J-aggregation of the porphyrin. Spectroscopic data supported the aggregation behavior. Two photon fluorescence microscopy (2PFM) has become a powerful technique in bioimaging for non-invasive imaging and potential diagnosis and treatment of a number of diseases via excitation in the near-infrared (NIR) region. The fluorescence emission upon two-photon absorption (2PA) is quadratically dependent with the intensity of excitation light (compared to the linear dependence in the case of one-photon absoprtion), offering several advantages for biological applications over the conventional one-photon absorption (1PA) due to the high 3D spatial resolution that is confined near the focal point along with less photodamage and interference from the biological tissues at longer wavelength (~700-900 nm). Hence, efficient 2PA absorbing fluorophores conjugated with specific targeting moieties provides an even better bioimaging probe to diagnose desired cellular processes or areas of interest The [alpha subscript v beta subscript 3] integrin adhesive protein plays a significant role in regulating angiogenesis and is over-expressed in uncontrolled neovascularization during tumor growth, invasion, and metastasis. Cyclic-RGD peptides are well-known antagonists of [alpha subscript v beta subscript 3] integrin which suppress the angiogenesis process, thus preventing tumor growth. In Chapter 5 the synthesis, photophysical studies and bioimaging is reported for a versatile norbornene-based block copolymer multifunctional scaffold containing biocompatible (PEG), two-photon fluorescent (fluorenyl), and targeting (cyclic RGD peptide) moieties. This water-soluble polymeric multi scaffold probe with negligible cytotoxicity exhibited much stronger fluorescence and high localization in U87MG cells (that overexpress integrin) compared to control MCF7 cells. The norbornene-based polymers and copolymers have quite remarkable versatility for the creation of advanced functional magnetic, photonic, and biophotonic materials.

Book Synthesis and Characterization of Functionalized Norbornene Monomers and Their Resulting Ring opening Metathesis Polymers and Copolymers

Download or read book Synthesis and Characterization of Functionalized Norbornene Monomers and Their Resulting Ring opening Metathesis Polymers and Copolymers written by Joshua David Biberdorf and published by . This book was released on 2011 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work reported herein describes efforts to create ring-opening metathesis block copolymers and homopolymers. The block copolymers were studied to gain insight into the local nanoscale environment of a block copolymer thin film. Additionally, perylene containing homopolymers were characterized in light of their possible use as an n-type material. In the first section of the thesis, the synthesis of diblock copolymers consisting of two blocks with very different dynamics is described. The covalent attachment of a molecular rotor which is sensitive to its local environment allowed the study of the dynamics of the polymers in thin films. The emissive intensity as a function of temperature allowed us to see discontinuity in the rates of change, indicating a change in the local environment corresponding to the transition of the polymer from a glassy to rubbery state. The corresponding temperature, to this event, is known as the glass transition temperature, Tg. Additionally, a polymer featuring a covalently bound n-type molecule, perylene diimide, was synthesized. The photophysical properties, including aggregation in dilute solution, are described. The material is expected to demonstrate the ability to efficiently transport negative charge, acting as n-type material in organic electronics.

Book Advances in Ring Opening Metathesis Polymerization

Download or read book Advances in Ring Opening Metathesis Polymerization written by and published by Wiley-VCH. This book was released on 2000-09-12 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume of Macromolecular Symposia contains contributions presented at the RO(M)P'99 International Symposium in Mons, Belgium. At this meeting, over one hundred chemists, physico-chemists, chemical engineers from the world of academia and industry, as well as students, discussed recent developments in mechanisms and kinetics in RO(M)P, synthesis and characterization of new macromolecular architectures, and new materials and applications via RO(M)P.

Book Synthesis Characterization and Ring Opening Metathesis Polymerization Activity of Pentamethylcyclopentadienyl Osmium Complexes

Download or read book Synthesis Characterization and Ring Opening Metathesis Polymerization Activity of Pentamethylcyclopentadienyl Osmium Complexes written by Julia Lynn Brumaghim and published by . This book was released on 1999 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Synthesis and Self assembly of Polymers Containing Dicarboximide Groups by Living Ring opening Metathesis Polymerization

Download or read book Synthesis and Self assembly of Polymers Containing Dicarboximide Groups by Living Ring opening Metathesis Polymerization written by Jake Dalphond and published by . This book was released on 2002 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: "DNA is remarkable because of its highly selective molecular recognition properties and self-assembly behavior. Recent attempts in generating biomimetic synthetic polymers have been flawed by a lack of structural control. To overcome this shortcoming, we generated molecular recognition polymers and copolymers containing a regioselective arrangement of thymine/uracil analogs via Ring-Opening Metathesis Polymerization (ROMP). The ROMP of exo-7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboximide was found to fulfill the criteria for a living polymerization. This gave access to polymers with narrow molecular weight distribution and well-controlled architecture. Furthermore, the living character of the reaction allowed for the facile synthesis of diblock copolymers. We have synthesized diblock copolymers containing a small hydrophilic block bearing molecular recognition units and a longer hydrophobic block consisting of long pendant alkyl chains. These copolymers undergo self-assembly into nanoscale aggregates with surface localized multi-point hydrogen bonding sites. Finally, molecular recognition properties of monomers and polymers containing the thymine/uracil analogs were characterized by 1H NMR and HPLC." --

Book Ring opening Metathesis Polymerization of Cyclopropenes and Ladderenes

Download or read book Ring opening Metathesis Polymerization of Cyclopropenes and Ladderenes written by Jessica Kalay Su and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The importance of polymer microstructure is manifested in nature, where the precisely regulated monomer sequence in biomacromolecules enables their controlled folding and assembly to afford vital biological functions. In the pursuit of man-made materials with sophisticated properties, the field of polymer chemistry has developed rapidly to enable the synthesis of polymers with controlled microstructures. Specifically, living polymerization techniques, such as ring-opening metathesis polymerization (ROMP), enable excellent control over polymer molecular weight, composition, and architecture. ROMP is driven primarily by the release of ring strain in cyclic olefin monomers, but surprisingly few studies have been performed on the ROMP of cyclopropenes (CPEs), the most strained monocyclic olefins. In 2015, our group discovered that a class of 1,1-disubstituted CPE undergoes selective single addition to Grubbs third generation catalyst. Monomers which undergo single addition are extremely rare for chain-growth polymerizations and are particularly useful for manipulating the monomer sequence in a polymer. As such, we focused our research efforts on discovering other CPEs that can undergo single addition and uncovering the mechanism and role of their substituents. We have synthesized a library of CPEs with various disubstitution patterns and substituents and systematically investigated their reactivity with Grubbs catalyst. We have found that 1,1-disubstitution of CPE is crucial for both preserving the stability of the propagating chain end and tuning the metathesis reactivity from living polymerization to single addition. The distinct reactivities stemmed from differences in sterics and/or chelation at the Ru alkylidene from C1 substituents after a single CPE ring-opening event, affecting the barrier to propagation. We have utilized the single addition reactivity of CPEs to synthesize alternating copolymers with diverse side chain and backbone functionalities from alternating ROMP of CPE with low-strain cyclic olefins. Recently, we have developed a strategy to precisely place discrete functionalities and side chains via ring-opened CPEs at pre-determined locations along a living ROMP polymer chain, with control over the location and number incorporated. This advance in polymer chemistry opens many exciting opportunities to manipulate the functionalities along well-controlled polymer chains for understanding the effects of their placement and sequence on polymer behaviors, controlling polymer folding/assembly, as well as synthesizing polymers with more complex nonlinear architectures with precision. Our group also recently reported a unique polymechanophore system, polyladderene, that undergoes force-triggered rearrangement into semi-conducting, insoluble polyacetylene. A notable feature in the design was the terminal strained cyclobutene on ladderene that allowed rapid ROMP. We have developed synthetic procedures to prepare triblock copolymers containing mechanically active polyladderene, since block copolymers can self-assemble in solution and bulk and facilitate incorporation of polyladderene with common polymers to impart the dramatic stress-response of polyladderene to diverse materials.

Book Metathesis Polymerization of Olefins and Polymerization of Alkynes

Download or read book Metathesis Polymerization of Olefins and Polymerization of Alkynes written by Yavuz Imamogammalu and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 443 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first NATO Advanced Study Institute on Olefin Metathesis and Polymerization Catalysts was held on September 10-22, 1989 in Akcay, Turkey. Based on the fundamental research of RRSchrock, RGrubbs and K.B.Wagener in the field of ring opening metathesis polymerization (ROMP), acyclic diene metathesis (ADMET) and alkyne polymerization, these areas gained growing interest within the last years. Therefore the second NATO-ASI held on metathesis reactions was on Ring Opening Metathesis Po lymerization of Olefins and Polymerization of Alkynes on September 3-16, 1995 in Akcay, Turkey. The course joined inorganic, organic and polymer chemists to exchange their knowledge in this field. This volume contains the main and short lectures held in Akcay. To include ADMET reactions better into the title of this volume we changed it into: Metathesis Polymerization of Olefins and Alkyne Polymerization. This volume is addressed to research scientists, but also to those who start to work in the area of olefin metathesis and alkyne polymerization. The topics of the course were: mechanism of ROMP reactions/ new catalysts for ROMP/ new products by ROMP/ new catalysts for ADMET/ new products by ADMETI degradation of polymer by metathesis reactions/ alkyne polymerization and metathesis/ industrial application of metathesis reactions. The Advanced Study Institute was generously sponsored by the Scientific Affairs Division of NATO and the editor gratefully acknowledges this sponsorship. We also thank the Members of the Local Organizing Committee for their engagement on a successful NATO-AS!.

Book Synthesis and Ring opening Metathesis Polymerization of Norbornenes Containing Pendent Aromatic and Aliphatic Side Chains

Download or read book Synthesis and Ring opening Metathesis Polymerization of Norbornenes Containing Pendent Aromatic and Aliphatic Side Chains written by and published by . This book was released on 1908 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of well-defined polynorbornenes containing pendent aromatic ether or aliphatic side chains have been prepared. Synthesis of the monomeric materials proceeded via initial cyclopentadienyl iron-mediated nucleophilic aromatic substitution reactions and DCC-mediated condensation reactions, followed by removal of the metal moiety via photolytic demetallation. Structural analysis of both the metallated and nonmetallated compounds was accomplished using homo- and heteronuclear correlation spectroscopic techniques as well as IR, MS and C, H elemental analysis. Subsequent ring-opening metathesis polymerization of these building blocks was achieved in the presence of a ruthenium-based catalyst, namely bis(tricyclohexylphosphine)benzylidene ruthenium (IV) dichloride, which liberated the resulting polymeric materials in high conversion of the monomer to the polymer. Gel permeation chromatography of each of the polymers revealed high molecular weights as well as low to narrow polydispersity indices. Thermal analysis of the aromatic ether functionalized polynorbornenes was accomplished using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). These results showed that when the number of aromatic groups pendent to the polymer chain increased (within each polymer repeat unit), a subsequent increase in the thermal stability was noted. TGA of the aliphatic-bridged systems revealed decreased thermal stability as the length of the aliphatic flexible spacer increased. Changing the spacer from a purely methylene-bridged system to one containing a tri(ethylene glycol) chain was found to increase the overall thermal properties of the resulting polymeric material.

Book Ring Opening Metathesis Polymerization

Download or read book Ring Opening Metathesis Polymerization written by Alexey Lyapkov and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, the olefins metathesis has established itself as a powerful tool for carbon-carbon bonds forming and has found numerous applications in polymer chemistry. One of the important directions of metathesis is the polymerization with cycle opening. A study of new ruthenium catalysts, resistant to the many functional groups effects, has showed the possibility of synthesizing functionalized polymers with unique properties. In this chapter, reactivity and activation parameters of eight different norbornene dicarboxylic acid alkyl esters in the presence of a Hoveyda-Grubbs II catalyst for the ring opening metathesis polymerization were determined by 1H NMR analysis in-situ. The molecules of esters differ in the aliphatic radical structure and the location of the substituent groups. Kinetic studies have shown that effective polymerization constants and activation parameters strongly depend on the monomer structure. It is shown that the elongation of the aliphatic radical does not significantly affect the reactivity, but significantly changes the activation parameters. The branching of the aliphatic radical significantly affects both the reactivity of the corresponding ester and the activation parameters of the polymerization. The position of the substituents in the norbornene ring of the ester also has a significant effect on the activation parameters of metathesis polymerization.

Book Synthesis of Catalysts for Ring Opening Metathesis Polymerization

Download or read book Synthesis of Catalysts for Ring Opening Metathesis Polymerization written by Martha Dolan Morton and published by . This book was released on 1993 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Functionalization of Inorganic Surfaces Using Ring opening Metathesis Polymerization

Download or read book Functionalization of Inorganic Surfaces Using Ring opening Metathesis Polymerization written by Zhebo Ding and published by . This book was released on 2003 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: