Acyclic Diene Metathesis Chemistry Research Articles

Synthesis of platinum-containing oligomers utilizing ADMET chemistry and polycondensation of a bisimide with α,ω-dibromoalkanes: examination of triplet–triplet annihilation upconversion

Pt-containing oligomers synthesized by ADMET oligomerization and polycondensation phosphoresced under N2, while did not under air. They served as sensitizers of triplet–triplet annihilation upconversion with 9,10-diphenylanthracene as an emitter.

Bulk Acyclic Diene Metathesis Polycondensation

AbstractBulk acyclic diene metathesis (ADMET) polymerization performed in the melt at temperatures up to 175 °C is completed using a cyclic (alkyl)(amino) carbene (CAAC) ruthenium‐based Grubbs catalyst. High temperature stability is investigated at temperatures well above conventional ADMET chemistry, leading to the highest weight‐average molecular weights ever achieved for any ADMET polymer. A study of isomerization tendency (double bond migration) is done via self‐metathesis of a small molecule model compound using CAAC catalysts. Minimal olefin isomerization is observed using appropriate catalyst ratios and temperatures.

A review of how to do an acyclic diene metathesis reaction

Recent reviews have described many advances made previously in acyclic diene metathesis (ADMET) polymerization. This mini-review emphasizes the experimental considerations for successful ADMET reactions. Several factors that are important in ADMET polymerization are discussed, following a description of the discovery and the polycondensation nature of ADMET chemistry. Typical experimental techniques including bulk and solution ADMET polymerizations commonly used to obtain high-molecular-weight polymers are also reviewed. © 2016 Society of Chemical Industry

Spectroscopic examinations of hydrogen bonding in hydroxy-functionalized ADMET chemistry.

Wide-angle X-ray scattering (WAXS) and temperature-dependent Fourier transform infrared spectroscopy (FTIR) spectroscopy are used to study hydrogen bonding interactions of a hydroxyl-functionalized polyethylene (PE) prepared by acyclic diene metathesis (ADMET) chemistry. The hydroxyl polymer exhibits an orthorhombic unit cell structure with characteristic reflection planes at (110) and (200), comparable to pure crystalline PE. These data unequivocally demonstrate that the OH branch is excluded from the PE lamellae. Furthermore, the polymer melts 100 °C higher than all previous analogous polymers possessing precision placed long aliphatic branches that also are excluded from PE lamellae. Temperature-dependent FTIR spectroscopy from ambient to 150 °C, followed by cooling to 125 °C supports exclusion of the hydroxyl group from the crystalline lattice. It is concluded that these hydroxyl groups form stable physical networks in the amorphous region via hydrogen bonding and are important for the overall morphology of such polymers.

Modeling Ethylene/Methyl Methacrylate and Ethylene/Methacrylic Acid Copolymers Using Acyclic Diene Metathesis Chemistry

The synthesis, characterization, and thermal behavior of ADMET models of ethylene/methyl methacrylate (EMMA) and ethylene/methacrylic acid (EMAA) copolymers are described. These model copolymers exhibit sharper melting transitions and lower melting points relative to random copolymers made using chain-growth polymerization methods. The EMMA and EMAA model copolymers are compared with ADMET ethylene-based model copolymers reported previously, comparisons which support the earlier finding that melting points decrease with an increase in the steric bulk of the pendant group.

Graft copolymers by acyclic diene metathesis and atom transfer radical polymerization techniques

Precise graft copolymer architectures were achieved by combining the macromonomer technique with the acyclic diene metathesis (ADMET) reaction. These well-defined copolymer structures were the result of proper monomer design before metathesis polymerization. Features such as length of the graft, nature, and concentration of the graft site along the backbone were manipulated via the combination of living atom transfer radical polymerization methods with ADMET chemistry. Furthermore, the physical behavior of these materials was altered such that they presented dissimilar thermal properties of either the homopolymers or random copolymers. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2816–2827, 2003

Carbosilane/carbosiloxane-based ADMET homopolymers and copolymers possessing latent reactivity

Reactive methoxy-functionalized carbosilane and carbosiloxane dienes can be either homopolymerized or copolymerized via acyclic diene metathesis (ADMET) polycondensation chemistry to produce reactive materials with mechanical behavior dependent on the molar ratios of the comonomers. The methoxy-functional group within the polycarbosilane repeat unit remains inert during the metathesis polymerization and can be triggered subsequently with water to generate crosslinks between polymer chains. In this way, linear, thermoplastic copolymers can be prepared with ADMET chemistry and converted into crosslinked, thermoset copolymers upon exposure to moisture. Crosslinked films containing 5–10% of the crosslinked hard segment are soft and flexible materials. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1544–1550, 2000

Silicon‐terminated telechelic oligomers by ADMET chemistry: Synthesis and copolymerization

Methoxydimethylsilane and chlorodimethylsilane-terminated telechelic polyoctenomer oligomers (POCT) have been prepared by acyclic diene metathesis (ADMET) chemistry using Grubbs' ruthenium Ru(Cl2)(CHPh)(PCy3)2 [Ru] or Schrock's molybdenum Mo(CHCMe2Ph)(N2,6C6H3iPr2)(OCMe(CF3)2)2 [Mo] catalysts. These macromolecules have been characterized by FTIR, 1H-, 13C-, and 29Si-NMR spectroscopy. The molecular weight distributions of these polymers have been determined by GPC and vapor pressure osmometry (VPO). The number-average molecular weight (Mn) values of the telechelomers are dictated by the initial ratio of the monomer to the chain limiter. The termini of these oligomers (Mn = 2000) can undergo a condensation reaction with hydroxy-terminated poly(dimethylsiloxane) (PDMS) macromonomer (Mn = 3300) [HOSi(CH3)2O{Si(CH3)2O}x Si(CH3)3], producing an ABA-type block copolymer, as follows: (CH3)3SiO [Si(CH3)2O]x[CHCH(CH2)6]y[OSi(CH3)2]xOSi(CH3)3. The block copolymers were characterized by 1H- and 13C-NMR spectroscopy, VPO, and GPC, as well as elemental analysis, and were determined by VPO to have a Mn of 8600. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 849–856, 1999

Silicon-terminated telechelic oligomers by ADMET chemistry: Synthesis and copolymerization

Methoxydimethylsilane and chlorodimethylsilane-terminated telechelic polyoctenomer oligomers (POCT) have been prepared by acyclic diene metathesis (ADMET) chemistry using Grubbs' ruthenium Ru(Cl2)(CHPh)(PCy3)2 [Ru] or Schrock's molybdenum Mo(CHCMe2Ph)(N2,6C6H3iPr2)(OCMe(CF3)2)2 [Mo] catalysts. These macromolecules have been characterized by FTIR, 1H-, 13C-, and 29Si-NMR spectroscopy. The molecular weight distributions of these polymers have been determined by GPC and vapor pressure osmometry (VPO). The number-average molecular weight (Mn) values of the telechelomers are dictated by the initial ratio of the monomer to the chain limiter. The termini of these oligomers (Mn = 2000) can undergo a condensation reaction with hydroxy-terminated poly(dimethylsiloxane) (PDMS) macromonomer (Mn = 3300) [HOSi(CH3)2O{Si(CH3)2O}x Si(CH3)3], producing an ABA-type block copolymer, as follows: (CH3)3SiO [Si(CH3)2O]x[CHCH(CH2)6]y[OSi(CH3)2]xOSi(CH3)3. The block copolymers were characterized by 1H- and 13C-NMR spectroscopy, VPO, and GPC, as well as elemental analysis, and were determined by VPO to have a Mn of 8600. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 849–856, 1999

Acyclic diene metathesis (ADMET) polymerization using a well‐defined ruthenium based metathesis catalyst

AbstractA series of α,ω‐dienes have been exposed to Ru(Cl2)(CHPh)(PCy3)2, [Ru] 3, metathesis catalyst under acyclic diene metathesis (ADMET) conditions, and the products were compared with those obtained previously using Schrock's well defined Mo and W alkylidenes. High molecular weight polymers can be synthesized using [Ru] 3 if lower monomer to catalyst ratios with respect to [Mo] 1 and [W] 2 are used. Monomer structure plays a role since 1,9‐decadiene produces molecular weights typical of ADMET chemistry, whereas 1,5‐hexadiene produces only oligomers. This decrease in reactivity is attributed to a manifestation of intramolecular π‐complexation of the tethered olefin in 1,5‐hexadiene polymerizations. Substituents at the 2‐position of α,ω‐dienes also affects polymerization in that only dimers can be produced from 2‐methyl‐1,5‐hexadiene, a result similar to the same reaction performed with [W] 2. Diallyl ether oligomerizes effectively in the presence of [Ru] 3 with a ratio of cyclics to oligomers comparable to results obtained with [Mo] 1 and [W] 2.