Polymerization of 1-methoxy-1-ethynylcyclohexane by transition metal catalysts

The polymerization of 1-methoxy-1-ethynylcyclohexane (MEC) was carried out by various transition metal catalysts. The catalysts MoCl₅, MoCl₄, and WCl₆ gave a relatively low yield of polymer (≤ 16%). The catalytic activity of Mo-based chloride catalyst was greater than that of W-based chloride catalyst. However, catalyst tungsten carbene complex (I) gave a larger molar mass and higher yield in the presence of a Lewis acid such as AlCl₃ than in the absence of a Lewis acid. The activity of the tungsten carbene complex was obviously affected by Lewis acidity. The catalyst PdCl₂ was a very effective catalyst for the present polymerization and gave polymers in a high yield. The structure of the resulting poly(MEC) was identified by various instrumental methods as a conjugated polyene structure having an α-methoxycyclohexyl substituent. The poly(MEC)s were mostly light-brown powders and completely soluble in various organic solvents such as tetrahydrofuran (THF), chloroform (CHCl₃), ethylacetate, n-butylacetate, dimethylformamide, benzene, xylene, dimethylacetamide, 1,4-dioxane, pyridine, and 1-methyl-2-pyrrolidinone. Thermogravimetric analysis showed that the polymer started to lose mass at 125°C and that maximum decomposition occurred at 418°C. The x-ray diffraction diagram shows that poly(MEC) has an amorphous structure. © 1997 John Wiley & Sons, Inc.     

Polymerization of 1-ethynylcyclohexene by tungsten and molybdenum-based catalysts

1-Ethynylcyclohexene, an acetylene derivative having cyclohexenyl substituent, was polymerized by various W- and Mo-based catalysts. WCl₆-EtAlCl₂ catalyst system was found to be very effective for this polymerization. The effects of the monomer-to-catalyst mol ratio, the initial monomer concentration, the temperature, and the cocatalysts for the polymerization of 1-ethynylcyclohexene by WCl₆ were investigated. The catalytic activity of Mo-based catalysts was found to be similar to that of W-based catalysts. The polymer structure was identified to have a conjugated polymer backbone carrying a cyclohexenyl substituent. The resulting polymers were light-brown powder and completely soluble in aromatic and halogenated hydrocarbon solvents such as chlorobenzene, benzene, chloroform, carbon tetrachloride, etc. Studies of the thermal properties and morphology of poly(1-ethynylcyclohexene) were also carried out. © 1995 John Wiley & Sons, Inc.     

Ring-opening polymerization of 2-azabicyclo-[2,2,1]-hept-5-en-3-one using metathesis catalysts

The ring-opening polymerization of an unsaturated bicyclic lactam, 2-azabicyclo-[2,2,1]-hept-5-en-3-one (ABHEO), was carried out using metathesis catalysts under various reaction conditions. It is observed that the best results (34% conversion and η_inh: 0.18 dL/g) were obtained when the mole ratios of ABHEO to WCl₆ as a catalyst and WCl₆ to AlEt₃ as a cocatalyst were 200 and 4, respectively. The infrared (IR) and nuclear magnetic resonance (¹H- and ¹³C-NMR) spectra of the polymer obtained indicated that the ABHEO was transformed to the ring-opened polymer, poly(2-pyrrolidone-3,5-diylvinylene) [poly(ABHEO)]. The resulting polymer was amorphous as determined by DSC analysis, which showed only secondary transition at 100°C.     

Polymerization of acenaphthylene by transition metal catalysts

The polymerization of acenaphthylene (ACN) was examined in the presence of the group V and VI transition metal salts such as WCl₆, MoCl₅, TaCl₅, and NbCl₅, as catalysts under various reaction conditions. These transition metal salts were found to be effective catalysts for the polymerization of ACN. The polymerization of ACN by WCl₆ in chlorobenzene proceeded at a high initial rate when the monomer to catalyst mole ratio was 200. In addition, it was observed that aromatic solvents generally were found to be superior to aliphatic solvents for both conversion and molecular weight. The structure of the resulting polymers was characterized by means of NMR, IR, UV, and x-ray diffraction. Emission properties were also investigated. Fluorescence emission spectra of the polymers obtained by WCl₆ as a catalyst varied strongly depending on the polymerization solvent. Thus, it appears that the polyacenaphthylene produced by WCl₆ was a different configuration dependent on the polymerization solvents used.     

Helical polyacetylenes carrying 2,2,6,6‐tetramethyl‐1‐piperidinyloxy and 2,2,5,5‐tetramethyl‐1‐pyrrolidinyloxy moieties: Their synthesis,properties, and function

2,2,6,6‐Tetramethyl‐1‐piperidinyloxy (TEMPO)‐ and 2,2,5,5‐tetramethyl‐1‐pyrrolidinyloxy (PROXYL)‐containing (R)‐1‐methylpropargyl TEMPO‐4‐carboxylate ( 1 ), (R)‐1‐methylpropargyl PROXYL‐3‐carboxylate ( 2 ), (rac)‐1‐methylpropargyl PROXYL‐3‐carboxylate ( 3 ), (S)‐1‐propargylcarbamoylethyl TEMPO‐4‐carboxylate ( 4 ), and (S)‐1‐propargyloxycarbonylethyl TEMPO‐4‐carboxylate ( 5 ) (TEMPO, PROXYL) were polymerized to afford novel polymers containing the TEMPO and PROXYL radicals at high densities. Monomers 1–3 and 5 provided polymers with moderate number‐average molecular weights of 8200–140,900 in 49–97% yields in the presence of (nbd)Rh⁺[η⁶‐C₆H₅B^?(C₆H₅)₃], whereas 4 gave no polymer with this catalyst but gave polymers possessing low M_n (3800–7500) in 56–61% yield with [(nbd)RhCl]₂‐Et₃N. Poly( 1 ), poly( 2 ), and poly( 4 ) took a helical structure with predominantly one‐handed screw sense in THF and CHCl₃ as well as in film state. The helical structure of poly( 1 ) and poly( 2 ) was stable upon heating and addition of MeOH, whereas poly( 4 ) was responsive to heat and solvents. All of the free radical‐containing polymers displayed the reversible charge/discharge processes, whose capacities were in a range of 43.2–112 A h/kg. In particular, the capacities of poly( 2 )–poly( 5 )‐based cells reached about 90–100% of the theoretical values regardless of the secondary structure of the polymer, helix and random. Poly( 1 ), poly( 2 ), and poly( 4 ) taking a helical structure exhibited better capacity tolerance towards the increase of current density than nonhelical poly( 3 ) and poly( 5 ) did. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5431–5445, 2007     

Synthesis and properties of poly(1‐naphthylacetylene) and poly(9‐anthrylacetylene)

Polymerizations of 1‐naphthylacetylene (1‐NA) and 9‐anthrylacetylene (9‐AA) by various transition metal catalysts were studied, and properties of the polymers were clarified. 1‐NA polymerized with WCl₆‐based catalysts to offer dark purple polymers in good yield. Especially, a binary catalyst composed of WCl₆ and Ph₃Bi gave a polymer with high molecular weight (M_w = 140×10³) and sufficient solubility in common solvents. The use of Mo and Rh catalysts, in contrast, resulted in the formation of insoluble red poly(1‐NA)s. 9‐AA gave insoluble polymers by both WCl₆‐ and MoCl₅‐based catalysts in moderate to good yields. Copolymerization of 9‐AA with 1‐NA by WCl₆–Ph₃Bi provided a soluble copolymer which exhibited the largest third‐order nonlinear optical susceptibilities (χ⁽³⁾(−3ω; ω, ω, ω) = 40×10⁻¹²) among all the substituted polyacetylenes synthesized so far. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 277–282, 1999     

Synthesis and properties of poly(dipropargyl sulfoxide)

The preparation and cyclopolymerization of dipropargyl sulfoxide were studied. The polymerization of dipropargyl sulfoxide was carried out by various transition metal catalysts. WCl₆–EtAlCl₂, MoCl₅, and PdCl₂ catalyst systems were very effective. The resulting poly(dipropargyl sulfoxide) structures were characterized by NMR (¹H and ¹³C), IR, and elemental analysis to have conjugated polyene units. Poly(dipropargyl sulfoxide) prepared by PdCl₂ was mostly soluble in organic solvents such as DMF and DMSO. Thermal and oxidative properties of poly(dipropargyl sulfoxide) were also studied. The electrical conductivity of iodine-doped poly(dipropargyl sulfoxide) was 5.2 × 10^?2 Ω^?1 cm^?1. Comparisons of poly(dipropargyl sulfoxide) properties with other similar polymers from dipropargyl sulfur derivatives such as dipropargyl sulfide and dipropargyl sulfone were also carried out. © 1993 John Wiley & Sons, Inc.     

Synthesis and Properties of Poly(Phenyl Propargyl Ether) and Its Homologues

Abstract

Various para-substituted phenyl propargyl ethers (substitutent = H, OMe, and CN) were synthesized and polymerized by transition metal catalyst systems including MoCl₅, WC1₆, and PdCl₂. The catalytic activity of MoCl₅-based catalysts was greater than that of WCl₆-based catalysts for the present polymerization. The polymer yield increased in the following order: H > OMe > CN, according to substitutents. The [poly-(pheny] propargyl ether) [poly(PPE)] and poly(methoxy phenyl propargyl ether) [poly(OMe-PPE)] obtained are completely soluble in various organic solvents such as chloroform, methylene chloride, THF, and 1,4-dioxane. However, poly(cyanophenyl propargyl ether) [poly(CN-PPE)] is partially soluble in various organic solvents such as those mentioned above. The electrical conductivities of the undoped and iodine-doped polymers and found to be about 10^?13 and 10^?4-10^?5 S/cm, respectively. The solubilities, thermal properties, and morphologies of the resulting polymers were also studied.     

Synthesis and properties of polymer brushes composed of poly(diphenylacetylene) main chain and poly(ethylene glycol) side chains

Novel cylindrical polymer brushes consisting of poly(diphenylacetylene) main chain and poly(poly(ethylene glycol) methyl ether monomethacrylate) (PPEGMA) side chains were synthesized by the diphenylacetylene macromonomer or side chain initiated atom transfer radical polymerization (ATRP) of poly(ethylene glycol) methyl ether monomethacrylate (PEGMA) from an bromo isobutyryl-bearing poly(diphenylacetylene) (poly(BrDPA)) method. The diphenylacetylene macromonomer, namely, DPA-PPEGMA, were prepared by the ATRP of PEGMA from bromo isobutyryl-bearing diphenylacetylene. DPA-PPEGMA was polymerized successfully with WCl₆-Ph₄Sn catalyst to give high molecular weight polymer brushes poly(DPA-PPEGMA). Meanwhile, polymer brushes (PDPA-g-PPEGMA) were obtained by ATRP of PEGMA from poly(BrDPA). The molecular weight of the side chains of PPEGMA could be controlled simply by modulating the ATRP time. The macromonomer and polymer brushes are soluble in nonpolar solvents such as toluene and chloroform. The polymers of poly(BrDPA) and poly(DPA-PPEGMA) absorb in the longer wavelength region, with two peaks at around 370 and 414 nm. The polymers are thermally stable and exhibit double crystallization and melting peaks during the cooling and heating scans.     

Polymerization of [o-(trimethylgermyl)phenyl] acetylene and polymer characterization

[o-(Trimethylgermyl)phenyl]acetylene was polymerized in the presence of WCl₆, W(CO)₆-hv, etc., to give polymers whose weight-average molecular weights reached ca. 7.0 X 10⁵ at the highest. When the MoOCl₄-n-Bu₄Sn-EtOH (1 : 1 : 1) catalyst was used, the polydispersity ratio of the polymer obtained was 1.08, and the number-average molecular weight increased in direct proportion to monomer conversion; these indicate that this polymerization is a living polymerization. The polymer had the structure ? [CH?C(C₆H₄-o-GeMe₃)]_n ? and was a dark purple solid (λ_max = 551 nm, ε_max = 6100 M^-1 cm^-1 in THF) soluble in organic solvents such as toluene and chloroform. The onset temperature of weight loss of the polymer in TGA in air was ca. 230°C, and the glass transition temperature was above 180°C. The Po₂ of the present polymer is 105 barrers—larger than the value of natural rubber and fairly close to that of poly(dimethylsiloxane). © 1993 John Wiley & Sons, Inc.     

Novel doubly polymerizable functional norbornene: Its synthesis,reactivity, and macromolecular architectures from a dual cure via ring‐opening metathesis polymerization and radical photopolymerization

A novel doubly polymerizable functional norbornene, 5‐(methacryloyloxyethylamino carboxylmethyl)bicyclo[2.2.1]hept‐2‐ene (NBMOACM), was prepared. The ring‐opening metathesis polymerization (ROMP) of NBMOACM was carried out to prepare polymers with crosslinkable side chains with the Grubbs catalyst. No gel formation occurred during the ROMP of NBMOACM. The ¹H NMR spectrum of poly(NBMOACM) showed broad signals between 5.10 and 5.40 ppm, corresponding to the vinyl protons of the cis and trans double bonds of the ring‐opened polymer. Increasing the ratio of the monomer concentration to the catalyst concentration resulted in the formation of higher molecular weight polymers. Poly(NBMOACM) was incorporated into poly(methyl methacrylate) [poly(MMA)] to produce AB crosslinked materials. These crosslinked materials [1 wt % poly(NBMOACM), 10% weight loss temperature = 300 °C in air] had higher thermal stability than pure poly(MMA) (10% weight loss temperature = 276 °C in air). © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6287–6298, 2006     

The polymerization of 3-chloro-1-propyne and 3-bromo-1-propyne with Mocl5 and WCL6 based initiators and the structure of the resulting polymers

The WCl₆ and MoCl₅ initiated polymerizations of 3-chloro-1-propyne and 3-bromo-1-propyne were performed in both halogenated and aliphatic non-nucleophilic and in aromatic nucleophilic solvents. The structure of the obtained polymers suggested that the polymerization reaction occurs in two steps. In both nucleophilic and non-nucleophilic solvents, the first step consists of the metathesis polymerization of 3-chloro(bromo)-1-propyne followed by electrophilic cis–trans isomerization leading to polymers containing trans-cisoidal allyl chloride or bromide structural units. When the polymerization is performed in non-nucleophilic solvents, in the second step an intramolecular electrophilic addition followed by elimination takes place. The resulting polymers contain a highly conjugated cyclopentadiene ladder structure. When the polymerization is performed in nucleophilic aromatic solvents, the intramolecular electrophilic addition competes with the electrophilic substitution of the solvent resulting in polymers containing high concentrations of arylpropenyl structural units. Subsequently, depending on the nucleophilicity of the polymerization solvent, the polymer structure contains structural units based on cyclopentadiene and/or arylpropenyl groups.     

Preparation and emission properties of various poly(dimethylsilylenearylenevinylene)s: Effects of geometric structures and π units on their emission properties

trans‐Poly(dimethylsilylenearylenevinylene)s (trans‐rich) and cis‐poly(dimethylsilylenearylenevinylene)s (cis‐rich) containing phenylene, biphenylene, and phenylenesilylenephenylene units were prepared by hydrosilylation catalyzed with the RhI(PPh₃)₃ complex. The addition of a phenylene π unit to poly(silylenephenylenevinylene) expanded the conjugation in the main chain, whereas the insertion of a dimethylsilylene σ unit in the biphenylene moiety reduced the conjugation. UV spectra of the trans‐type polymers showed redshifts and hyperchromic effects with respect to those of the cis‐type polymers, indicating wider conjugation, and the quantum yields of emission of the former polymers were much higher than those of the latter polymers. The quantum yield of the trans‐rich polymer with the biphenylene moiety reached 0.15, which was about 10² times as large as those of trans‐type polymers with phenylene (3.4 × 10^?3) and phenylenesilylenephenylene (1.9 × 10^?3) moieties. The effects of the geometric structure and π unit on the absorption and emission properties of these polymers were examined with molecular orbital methods. © 2002 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 535–543, 2002; DOI 10.1002/pola.10139     

Polymerization of α-Hydroxyacetylenes by Transition Metal Catalysts

Abstract

α-Hydroxyacetylenes (2-propyn-1-ol, DL-3-butyn-2-ol, 1-octyn-3-ol, 2-phenyl-3-butyn-2-ol) with a hydroxy functional group were polymerized by various Mo- and W-based catalysts. In general, the catalytic activities of Mo-based catalysts were greater than those of W-based catalysts for these polymerizations. In the polymerization of 2-propyn-l-ol, MoCl₅ alone and the MoCl₅-EtAlCl₂ catalyst system gave a quantitative yield of polymer. In the polymerization of 2-propyn-l-ol and its homologues by Mo-based catalysts, the polymer yield decreased as the bulkiness of the substituent increased. On the other hand, the polymer yield increased as the bulkiness of the substituent increased in WCl₆-EtAlCl₂-catalyzed polymerization. Polymers with a bulkier substituent showed better solubility in organic solvents than those without a substituent [e.g., poly (2-propyn-l-ol)]. The structures of the resulting polymers were characterized by various instrumental methods such as ¹H- and ¹³C-NMR, IR, and UV-visible spectroscopies. Thermogravimetric analyses and thermal transitions of the resulting polymers were also studied.     

Stereoregularity of poly(vinyl ether)

α-Methylvinyl isobutyl and methyl ethers were polymerized cationically and the structure of the polymers was studied by NMR. Poly(α-methylvinyl methyl ether) polymerized with iodine or ferric chloride as catalyst was found to be almost atactic, whereas poly(α-methylvinyl isobutyl ether) polymerized in toluene with BF₃OEt₂ or AlEt₂Cl as catalyst was found to be isotactic. In both cases, the addition of polar solvent resulted in the increase of syndiotactic structure as is the case with polymerization of alkyl vinyl ether. tert-Butyl vinyl ether was polymerized, and the polymer was converted into poly(vinyl acetate), the structure of which was studied by NMR. A nearly linear relationship between the optical density ratio D₇₂₂/D₇₃₆ in poly(tert-butyl vinyl ether) and the isotacticity of the converted poly(vinyl acetate) was observed.     

Synthesis of regiospecifically meta-substituted poly(phenylacetylene)s and some of their electrical properties

The syntheses, characterizations, and electrical properties of four regiospecifically substituted poly(phenylacetylene)s are described. Tungsten(VI) chloride/tetra-n-butyltin (WCl₆/n-Bu₄Sn) catalyst system (Higashimura–Masuda, H.–M. catalyst) was used to polymerize 3-bromo-, 3-chloro-, 3-trimethylsilyl-, and 3-trimethylstannylphenylacetylenes in order to obtain high-molecular-weight and soluble materials. Characterizations of these polymers were done by IR and UV spectroscopic methods, GPC, DSC, and elemental analysis. The electrical conductivities of the polymers were measured on the surface of pressed pellets by a four-point probe.     

Synthesis and absorption/emission properties of novel poly(silylenearylenevinylene)s

Polymerization of p-(dimethylsilyl)phenylacetylene in toluene at 25 and 80 °C with RhI(PPh₃)₃ catalyst afforded highly regio- and stereoregular poly(dimethylsilylene-1,4-phenylenevinylene)s [cis- and trans-poly( 1a )s] containing 98% cis- and 99% trans-vinylene moieties, respectively. The trans-type polymers exhibited redshifts and hyperchromic effects in the ultraviolet–visible spectrum as compared with the cis-type counterparts. Photoirradiation of cis- and trans-poly( 1a )s gave cis-rich mixtures at equilibrium states. The trans and cis polymers exhibited different emission properties, for example—trans polymer, emissn λ_max = 400 nm, quantum yield: 3.4 × 10⁻³ and cis polymer, emissn λ_max = 380 nm, quantum yield: 1.5 × 10⁻³. Besides poly( 1a ), poly(dimethylsilylenearylenevinylene)s containing biphenylene and phenylenesilylenephenylene units [poly( 3 )] were prepared. The extent of conjugation in these polymers decreased in the orders of biphenylene > phenylene > phenylenesilylenephenylene as well as trans-vinylene > cis-vinylene. The quantum yield of the trans-rich polymer with biphenylene moiety was fairly large and 0.15. Polyaddition of 1,4-bis(dimethylsilyl)benzene and three types of diethynylarenes (4,4′-diethynylbiphenyl, 2,7-diethynylfluorene, and 2,6-diethynylnaphthalene) catalyzed by RhI(PPh₃)₃ provided novel regio- and stereoregular polymers [poly( 6 )]. These polymers displayed blue light emission with high quantum yields (4–81%). © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3615–3624, 2003     

Polymerization of N-carbazolylacetylene by various transition metal catalysts and polymer properties

N-Carbazolylacetylene (CzA) was polymerized in the presence of various transition metal catalysts including WCl₆, MoCl₅, [Rh(NBD)Cl]₂, and Fe(acac)₃ to give polymers in good yields. The polymers produced with W catalysts were dark purple solids and soluble in organic solvents such as toluene, chloroform, etc. The highest weight-average molecular weight of poly(CzA) reached about 4 × 10⁴. In the UV–visible spectrum in CHCl₃, poly(CzA) exhibited an absorption maximum around 550 nm (ε_max = 4.0 × 10³ M⁻¹ cm⁻¹) and the cutoff wavelength was 740 nm, showing a large red shift compared with that of poly(phenylacetylene) [poly(PA)]. Poly(CzA) began to lose weight in TGA under air at 310°C, being thermally more stable than poly(PA) and poly[3-(N-carbazolyl)-1-propyne]. Poly(CzA) showed a third-order susceptibility of 18 × 10⁻¹² esu, which was 2 orders larger than that of poly(PA). © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2489–2492, 1998     

Cyclopolymerization of dipropargyl isopropylidene malonate and characterization of the product

The polymerization of dipropargyl isopropylidene malonate (DPIPM) was polymerized by WCl₆ and MoCl₅ associated with various organometallic cocatalysts. MoCl₅ was found to be the most effective catalyst and Ph₄Sn was observed to have a high cocatalyst activity. Structure and physical properties of poly(DPIPM) were investigated. The spectral data indicated that poly(DPIPM) contains alternating double and single bonds along the polymer backbone and a cyclic recurring unit. The poly(DPIPM) was partially soluble in common organic solvents. The M?_n values of the polymer from soluble fraction were in the range of 5100–8000 relative to polystyrene standards by GPC. In addition, poly(DPIPM) possesses good stability to air oxidition. When poly(DPIPM) is exposed to iodine vapor, the electrical conductivity was increased from 4.5 × 10^?11 to 7 × 10^?2 S/cm. © 1993 John Wiley & Sons, Inc.     

Synthesis and Thermal Properties of Regio‐ and Stereoregular Poly(silylene‐1,4‐phenylenevinylene)s

Polymerization of p‐(dimethylsilyl)phenylacetylene in toluene at 25 and 80°C using RhI(PPh₃)₃ as the catalyst afforded highly regio‐ and stereoregular poly(dimethylsilylene‐1,4‐phenylenevinylene)s (cis‐ 3 a and trans‐ 3 a ) containing 98% cis‐ and 99% trans‐vinylene moieties, respectively. Similarly, poly(butylmethylsilylene‐1,4‐phenylenevinylene)s ( 3 b with 91% cis‐ and 95% trans‐structures) and poly(diisopropylsilylene‐1,4‐phenylenevinylene) with 95% trans‐structure were synthesized. All polymers were soluble in common organic solvents. The trans‐type polymers showed red shifts and hyperchromic effects in the UV‐visible spectrum. The onset temperature of weight loss (T₀) of cis‐ 3 a was much higher than that of trans‐ 3 a .