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(2-vinylpyridine) and poly-(4-vinylpyridine)

In order to determine the stereoregularity of poly(4-vinylpyridine), 4-vinylpyridine-β,β-d₂ was synthesized from 4-acetylpyridine. The ¹H-NMR spectra of the deuterated and nondeuterated polymers were measured and analyzed. From the ¹H-NMR spectra of poly(4-vinylpyridine-β,β-d₂), triad tacticity can be obtained, while the ¹H-NMR spectra of nondeuterated poly(4-vinylpyridine) give the fraction of isotactic triad. The ¹³C-NMR spectra of poly(4-vinylpyridine) were also observed, and the spectra of C₄ carbon of polymers were assigned by the pentad tacticities. The fraction of isotactic triad of poly(2-vinylpyridine) and poly(4-vinylpyridine) obtained under various polymerization conditions were determined. The radical polymerization and anionic polymerizations with phenylmagnesium bromide and n-butyllithium as catalysts of 4-vinylpyridine gave atactic polymers.     

Synthesis,geometric structure,and properties of poly(phenylacetylenes) with bulky para-substituents

Phenylacetylenes (PAs) with bulky substituents (adamantyl, tert-butyl, and n-butyl groups) at the para-position polymerized in good yields with Fe, Rh, Mo, and W catalysts. The formed polymers were soluble, and their number-average molecular weights were in the range of thousands to hundred thousands. Whereas it is known that the poly(PA) obtained with the Fe catalyst is an insoluble cis-cisoidal polymer, the present polymers formed with the same catalyst were totally soluble in many solvents such as benzene and CHCl₃. The ¹H- and ¹³C-NMR and DSC data revealed that both of the polymers formed with the Fe and Rh catalysts had virtually all-cis structures, while those with the Mo and W catalysts had cis-rich and trans-rich structures, respectively. Cis-cisoidal and cis-transoidal structures of para-substituted poly(PAs) could not be distinguished because of their good solubility. The bulky substituents raised the temperature of cis–trans isomerization and improved the thermal stability of the polymers. Poly(p-t-BuPA) showed gas permeability higher than that of poly(PA). © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 3157–3163, 1998     

Synthesis of fusible and soluble conducting polyfluorene derivatives and their characteristics

Conducting polyfluorene derivatives with alkyl chains—poly(9-alkylfluorene)s and poly-(9,9-dialkylfluorene)s—have been synthesized by chemical polymerization utilizing FeCl₃ as an oxidizing agent. The polymers obtained are found to be soluble in conventional organic solvents such as chloroform and have been characterized by ¹H- and ¹³C-NMR. The results indicate that the fluorene moeities are mainly linked in the 2,7′-fashion to yield the straight chain polymer. The degree of polymerization is estimated (by gel permeation chromatography) to be of the order of 10. The polymers are found to be fusible and the thermal properties of the polymers have been characterized by differential scanning calorimetry. The glass transition temperature is found to decrease with an increase of the alkyl chain length. © 1993 John Wiley & Sons, Inc.     

MULTIFUNCTIONAL HYDROPHILIC POLYMERS

ABSTRACT

Different types of multifunctional hydrophilic polymers were synthesized and characterized in view of their possible biomedical application. Several poly(amide)s and poly(ester-amide)s containing oligo(oxyethylene) segments and tartaric or succinic acid residues were prepared by activated polycondensation methods. New functional derivatives of β-cyclodextrin were obtained by reaction with glycidyl ether of protected polyols. The mechanism of β-cyclodextrin polymerization with epichlorohydrine was investigated by ¹³C-NMR spectroscopy.     

Stereoregularity of poly(α-methylvinyl alkyl ether)s determined by 1H- and 13C-NMR spectroscopy

α-Methylvinyl methyl ether, ethyl ether, and isobutyl ether were polymerized under various polymerization conditions and the structure of the polymers was determined by ¹H- and ¹³C-NMR spectroscopy. α-Methyl and β-methylene carbon spectra of poly(α-methylvinyl isobutyl ether) showed splitting and were analyzed by triad and tetrad sequences. β-Methylene carbon spectra of poly(α-methylvinyl ethyl ether) also showed splitting. When Eu(fod)₃ was added, α-methyl and methoxy proton spectra in benzene of poly(α-methylvinyl methyl ether) showed splitting assigned to triad tacticities. All the polymers obtained in polar solvents exhibited an increase in syndiotacticity. The polymerization mechanism is discussed.     

Polymerization of substituted acetylenes by various rhodium catalysts: Comparison of catalyst activity and effect of additives

This research deals with comparison of the activity of various Rh catalysts in the polymerization of monosubstituted acetylenes and the effect of various amines used in conjunction with [Rh(nbd)Cl]₂ in the polymerization of phenylacetylene. A zwitterionic Rh complex, Rh⁺(nbd)[(η⁶‐C₆H₅)B^?(C₆H₅)₃] ( 3 ), was able to polymerize phenylacetylene ( 5a ), t‐butylacetylene ( 5b ), N‐propargylhexanamide ( 5c ) and n‐hexyl propiolate ( 5d ), and displayed higher activity than the other catalysts examined, that is [Rh(nbd)Cl]₂ ( 1 ), [Rh(cod)(O‐o‐cresol)]₂ ( 2 ), and Rh‐vinyl complex ( 4 ). Monomers 5a and 5c polymerized virtually quantitatively or in fair yields with all these catalysts, while monomer 5b was polymerizable only with catalyts 3 and 4 . Monomer 5d did not polymerize in high yields with these Rh complexes. The catalytic activity tended to decrease in the order of 3 > 4 > 2 > 1 . Although polymerization of 5a did not proceed at all in toluene with [Rh(nbd)Cl]₂ alone, it smoothly polymerized in the presence of various amines as cocatalysts. The polymerization rate as well as the molecular weight of polymer depended on the basicity and steric bulkiness of amines. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4530–4536, 2005     

Polymerization of Bis(Pyridine)bis-(2,4,6-tribromophenoxo)copper(II) Complex (Py2Cu(TBrP)2) by Electrooxidation and Structural Characterization by 1H-NMR, 13C-NMR,and FTIR Spectroscopies

Abstract

Electroinitiated polymerization of bis(2,4,6-tribromophenoxo)- bis(pyridine)copper(II) complex was achieved in dimethylformamide-tetrabutylammonium tetrafluoroborate solvent-electrolyte couple under air or nitrogen at room temperature by constant potential electrolysis. Polymerization conditions were based on the peak potentials measured by cyclic voltammetry. The structural analyses of the polymers were done by ¹H-NMR, ¹³C-NMR, and FTIR spectral analyses along with molecular weight measurements by cryoscopy. The poly(dibromo phenylene oxide)s obtained only at oxidation potentials in either atmosphere were found to be highly linear, indicating mainly 1,4-catenation was taking place.     

Rare Earth Metal-Initiated Polymerizations of Polar and Nonpolar Monomers

Abstract

Organolanthanide(III) initiated polymerization of methyl methacryate gave both syndiotactic and isotactic living polymers of high molecular weight. Organolanthanide(III) initiated polymerization of alkyl acrylates also gave high molecular weight poly(alkyl acrylate)s with very narrow molecular weight distribuion in high yield. Molecular weights of the resulting polymers increased linearly with the conversion. Random and block copolymerizations of alkyl acrylates with methyl methacrylate were realized successfully. For the sake of development of the olefin polymerization catalyst, bulky substituents were introduced into Me₂Si bridged Cp rings and they were used as ligands for the lanthanide complexes. Tri- and divalent lanthanide complexes with such ligands showed high activity for olefin polymerization and gave high molecular weight polyolefins.     

Synthesis and properties of a soluble and widely conjugated polyacetylene with anthryl pendant

The metathesis polymerization of an anthrylacetylene bearing an alkyl ester group, 9‐(10‐hexoxycarbonyl)anthrylacetylene ( 1 ), was conducted with various transition‐metal catalysts. A completely soluble black polymer was obtained from 1 in a good yield when W‐based catalysts were employed. The polymerization at a high monomer concentration (1 M) and a high temperature (80 °C) led to the formation of poly( 1 ) with a weight‐average molecular weight of 297 × 10³ in an 80% yield. The use of cocatalysts unexpectedly decreased both the yield and molecular weight of poly( 1 ). Rh‐catalyzed and Mo‐catalyzed polymerizations, however, resulted in poor yields of the polymer. The ultraviolet–visible spectrum of poly( 1 ) showed a significantly redshifted absorption (λ_max = 571) with a cutoff at 780 nm, which verified the very high order of conjugation of the main chain. Poly( 1 ) exhibited the largest third‐order nonlinear optical susceptibility [χ⁽³⁾ (−ω; ω, 0, 0) = − 1.9 × 10⁻¹⁰ esu] among the polymers from the monosubstituted polyacetylenes synthesized so far. The electrical conductivity of poly( 1 ) in an I₂‐doped state was 8.77 × 10⁻⁴ at 293 K. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4717–4723, 2000     

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 of well-defined norbornenyl-terminated poly(alkyl methacrylate)s by group transfer polymerization and their grafting-through ring-opening metathesis polymerization

Highly efficient syntheses of poly(alkyl methacrylate)-based brush polymers were accomplished via a facile group transfer polymerization (GTP) and a consecutive grafting-through ring-opening metathesis polymerization. The GTP system, composed of the norbornenyl-methyl trimethylsilyl ketene acetal initiator and the N-(trimethylsilyl) bis(trifluoromethanesulfonyl)imide catalyst, rapidly and quantitatively generates norbornenyl-terminated poly(alkyl methacrylate) macromonomers with very narrow polydispersities (M_w/M_n < 1.10). The ring-opening metathesis polymerization of methacrylate macromonomers using Grubbs third generation catalyst successfully generated a group of methacrylate-based brush polymers, which assured the high quality of the macromonomers obtained from GTP.     

A review of: “The Effects of Hostile Environments on Coattings and Plastics,Acs. D. P. Garner and G. A. Stahl (Editors): Symposium Series 229, American Chemical Society,Washington, D.C., 1983, 339 pp., U.S. and Canada $47.95, export $57.95.”

Rh‐catalyzed polymerization of a new N‐propargylamide monomer having a galactose residue was investigated. The polymerization proceeded in a mixed solvent of THF and water to produce the galactose‐carrying poly(N‐propargylamide) consisting of cis‐isomer. The copolymerization of the monomer with the N‐propargylamide having the alkyl chain was also carried out.     

Catalytic polymerization of phenylacetylene with dimeric [Rh(OMe)(cod)]2 complex in ionic liquids

Dimeric rhodium(I) complex [Rh(OMe)(cod)]₂ was found to be an active catalyst of phenylacetylene polymerization to poly(phenylacetylene) (PPA) in ionic liquids containing imidazolium or pyridinium cations. The highest yield of PPA (92%) was obtained in 1‐butyl‐4‐methylpyridinium tetrafluoroborate as reaction medium. The yield of PPA in imidazolium ionic liquids containing BF₄^? or PF₆^? anions increased to 83–99% when Et₃N or cycloocta‐1,5‐diene were added as co‐catalysts. In 1‐methyl‐3‐octylimidazolium chloride (MOI · Cl) polymerization rate was much lower than in other ionic liquids, although the highest M_w (72 400) was obtained. Spectroscopic studies confirmed that [Rh(OMe)(cod)]₂ reacted with MOI · Cl forming new carbene Rh(I) complex, which can participate in the polymerization process. Copyright © 2006 John Wiley & Sons, Ltd.     

Polymerization of 3‐ethynylthiophene with homogeneous and heterogeneous Rh catalysts

3‐Ethynylthiophene (3ETh) was polymerized with Rh(I) complexes: [Rh(cod)acac], [Rh(nbd)acac], [Rh(cod)Cl]₂, and [Rh(nbd)Cl]₂ (cod is η²:η²‐cycloocta‐1,5‐diene and nbd η²:η²‐norborna‐2,5‐diene), used as homogeneous catalysts and with the last two complexes anchored on mesoporous polybenzimidazole (PBI) beads: [Rh(cod)Cl]₂/PBI and [Rh(nbd)Cl]₂/PBI used as heterogeneous catalysts. All tested catalyst systems give high‐cis poly(3ETh). In situ NMR study of homogeneous polymerizations induced with [Rh(cod)acac] and [Rh(nbd)acac] complexes has revealed: (i) a transformation of acac ligands into free acetylacetone (Hacac) occurring since the early stage of polymerization, which suggests that this reaction is part of the initiation, (ii) that the initiation is rather slow in both of these polymerization systems, and (iii) a release of cod ligand from [Rh(cod)acac] complex but no release of nbd ligand from [Rh(nbd)acac] complex during the polymerization. The stability of diene ligand binding to Rh‐atom in [Rh(diene)acac] catalysts remarkably affects only the molecular weight but not the yield of poly(3ETh). The heterogeneous catalyst systems also provide high‐cis poly(3ETh), which is of very low contamination with catalyst residues since a leaching of anchored Rh complexes is negligible. The course of heterogeneous polymerizations is somewhat affected by limitations arising from the diffusion of monomer inside catalyst beads. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2776–2787, 2008     

Inclusion polymerization of 1-chlorobutadiene in a deoxycholic acid canal

Inclusion polymerization of 1-chlorobutadiene was studied using 3α,12α-dihydroxy-5β-cholan-24-oic acid (deoxycholic acid, DCA) as host molecules. It was found that the poly(1-chlorobutadiene) had almost 100% of head to tail, trans-1,4-structure on the basis of ¹³C-NMR and IR spectroscopies. This was the first example of preparing the highly regulated poly(1-chlorobutadiene) by using the inclusion polymerization technique. The polymers obtained were optically active and the maximum value of specific rotation was [α]_D-41.9°. Both the rate constants and the value of activation energy of the elementary reactions of inclusion polymerization of 1-chlorobutadiene were determined by graphical evaluation. The activation energy of propagation and termination was 11.7 and 11.1 kcal/mol, respectively.     

编织芳基网络聚合物负载Rh催化剂上高碳烯烃氢甲酰化反应性能

考察了编织芳基网络聚合物（KAPs）负载的Rh催化剂（Rh/KAPs）在高碳烯烃氢甲酰化反应中的催化性能. 结果表明,三苯基膦-苯基底KAPs负载Rh催化剂（Rh/KAPs-1）具有优异的高碳烯烃氢甲酰化反应活性,产物醛收率显著高于Rh/SiO₂催化剂. 傅里叶变换红外光谱、热重、氮气吸附-脱附、X射线衍射、透射电子显微镜、¹³C核磁共振和³¹P核磁共振结果显示,Rh/KAPs-1催化剂具有优异的热稳定性及大的比表面积和多级孔道结构,Rh颗粒处于高度分散状态,并可在反应过程中形成均相催化活性物种.     

Identification of Initiator Fragments in Polyisobutylene by Nmr Spectroscopy

Abstract

Deuterated polyisobutylenes carrying protonated initiator fragments were prepared by the living polymerization technique employing perdeuterated isobutylene [CD₂=C(CD₃)₂] and select protonated initiators (see Scheme 1). The polymers were analyzed by ¹H- and ¹³C-NMR spectroscopy, and the resonances due to the protic initiator fragments were unequivocally assigned. The assignments of ¹³C-NMR signals were affected by the distortionless enhancement by polarization transfer mode of spectra accumulation.     

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.     

Kinetics of polymerization of 1-octene with Mgcl2-supported Ticl4 catalysts

A number of TiCl₄ catalysts supported on MgCl₂ which was activated by the recrystallization method using different alcohols were prepared with ethyl benzoate or dibutyl phthalate as the internal electron donor. All the catalysts were characterized by BET, x-ray diffraction, and hydrolysis–GC analysis. Kinetics of polymerization of 1-octene was studied with three of the above catalysts (having different internal electron donors) activated by AlEt₃. The rate of polymerization increased linearly with increasing temperature, and catalyst and monomer concentrations. From the Arrhenius plot, the overall activation energies of polymerization were determined and the dependence of rate on the AlEt₃ concentration could be explained by the Langmuir-Hinshelwood mechanism. ¹³C-NMR was used to study the effect of internal electron donors on the % isotacticity of poly(1-octene). The catalytic activities of all the catalysts were compared in 1-octene polymerization. © 1994 John Wiley & Sons, Inc.