Synthesis and properties of germanium-containing poly(diphenylacetylenes)

1-Phenyl-2-[m-(trimethylgermyl)phenyl]acetylene (m-Me₃GeDPA) and 1-phenyl-2-[p-(trimethylgermyl)phenyl]acetylene (p-Me₃GeDPA) polymerized with TaCl₅–cocatalyst systems to provide in high yields new polymers having weight-average molecular weights over 1 × 10⁶. Poly(m-Me₃GeDPA) was a yellow solid, which completely dissolved in toluene, chloroform, etc., to form a tough film by solution casting. Poly(p-Me₃GeDPA) was also a yellow solid and partly insoluble in any solvents. The onset temperatures of weight loss for these polymers in the thermogravimetric analysis in air were as high as ca. 400°C. The oxygen permeability coefficient of poly(m-Me₃GeDPA) was 1100 barrers (25°C), which is about twice that of poly(dimethylsiloxane). © 1996 John Wiley & Sons, Inc.     

Polymerization of diphenylacetylenes having very bulky silyl groups and polymer properties

Polymerization and polymer properties of 1-phenyl-2-[4-(triphenylsilyl)phenyl]acetylene (pPh₃SiDPA) and 1-phenyl-2-[4-(triisopropylsilyl)phenyl]acetylene (piPr₃SiDPA), which have very bulky silyl groups, were examined. These monomers polymerized in good yields in the presence of TaCl₅-based catalysts. The highest weight-average molecular weights of poly(pPh₃SiDPA) and poly(piPr₃SiDPA) reached about 1 × 10⁶ and 4.8 × 10⁶, respectively. The polymers were yellow to orange-colored solids which were soluble in toluene, chloroform, etc., and provided free-standing films by solution casting. The onset temperatures of weight loss of poly(pPh₃SiDPA) and poly(piPr₃SiDPA) in TGA in air were 430 and 270°C, respectively. The oxygen permeability coefficients of poly(pPh₃SiDPA) and poly(piPr₃SiDPA) at 25°C were 3.8 and 20 barrers, respectively, and relatively small. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2721–2725, 1998     

Polymerization of Si-containing acetylenes. XIV. Polymerization of diphenylacetylenes with bulky silyl groups and polymer properties

Polymerization and polymer properties of diphenylacetylenes with bulky silyl groups (SiMe₂–i-Pr, SiMe₂–t-Bu, SiMe₂Ph, SiEt₃) at para or meta position were studied under comparison with those of the SiMe₃ derivatives. The present monomers polymerized in good yields with TaCl₅-cocatalysts to form high molecular-weight polymers (M _w > 4 × 10⁵). The polymer yields of para-substituted monomers were similar to that of the SiMe₃ derivative, while those of meta substituted monomers were lower than that of m-SiMe₃ derivative. Most of the polymers were totally soluble in common solvents such as toluene and CHCl₃, although the polymers with p-SiMe₂–t-Bu and p-SiMe₂Ph groups were partly insoluble in all solvents. These polymers resembled SiMe₃-containing homologues in the UV-visible absorption and thermal stability. The oxygen permeability coefficients of these polymers were in the range of 10^?9?10^?8 cm³ (STP) cm/(cm²·s cm Hg)—lower than those of the corresponding SiMe₃-containing polymers. © 1993 John Wiley & Sons, Inc.     

Synthesis and properties of a poly(diphenylacetylene) containing carbazolyl groups

1-(p-N-Carbazolylphenyl)-2-phenylacetylene (p-CzDPA) was polymerized by TaCl₅–co-catalyst systems (cocatalysts: n-Bu₁Sn, Et₃SiH, and 9BBN) to produce acetone-insoluble polymers in about 60-70% yields. Poly(p-CzDPA) was a yellowish-orange solid, most part of which was soluble in toluene, chloroform, etc., and its weight-average molecular weights were around 4×10⁵. This polymer formed a tough film by solution casting, and was thermally very stable (the onset temperature of weight loss in TGA in air 470°C). The oxygen per-meability coefficient of the polymer at 25°C was lower than two barrers. The present polymer showed photoconductivity and redox activity. © 1995 John Wiley & Sons, Inc.     

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 and properties of poly(phenylacetylenes) having o-silylmethyl groups

Novel phenylacetylene (PA) monomers, which have o-silylmethyl groups of different bulkinesses, i.e., o-Me₃SiCH₂PA, o-Et₃SiCH₂PA, and o-t-BuMe₂Si-CH₂PA, polymerized with W and Mo catalysts in high yields. The MoCl₅-Ph₄Sn catalyst achieved the highest weight-average molecular weights (M _w 7 × 10⁵ ? 12 × 10⁵), and the M _w increased as the ortho-substitutent became bulkier (e.g., M_w of o-t-BuMe₂SiCH₂PA: 12 × 10⁵). These monomers polymerized in a living fashion by the MoOCl₄-n-Bu₄Sn-EtOH catalyst. The resulting polymers were soluble in common solvents such as toluene and chloroform. In the UV-visible spectra, a tendency was observed that absorption maxima shifted to longer wavelengths as the substituents became bulkier. Membranes of the polymers were fairly permeable to gases (e.g., oxygen permeability coefficients 30-80 barrers). Though o-(Me₃Si)₂CHPA also polymerized with W and Mo catalysts, the product polymer was partly insoluble in any solvent. © 1995 John Wiley & Sons, Inc.     

Synthesis and properties of polyacetylenes with adamantyl groups

Three disubstituted acetylenes with an adamantyl group—1-(p-adamantylphenyl)-2-chloroacetylene (ClpAdPA), 1-(p-adamantylphenyl)-1-propyne (pAdPP), and 1-(p-adamantylphenyl)-2-phenylacetylene (pAdDPA)—polymerized in good yields in the presence of MoCl₅- or TaCl₅-based catalysts. The highest weight-average molecular weights of poly(ClpAdPA), poly(pAdPP), and poly(pAdDPA) reached 3.6 × 10⁵, 1.1 × 10⁶, and 6.0 × 10⁶, respectively. The polymers were yellow to white solids and completely soluble in toluene, chloroform, and so forth. These polymers thermally were fairly stable, and the onset temperatures of weight loss in air were over 360 °C. Poly(pAdPP) and poly(pAdDPA) provided free-standing films by solution casting, and their oxygen permeability coefficients (P_O2) at 25 °C were 8.6 and 55 barrers [1 barrer = 1 × 10⁻¹⁰ cm³ · (STP) · cm/(cm² · s · cm Hg)], respectively, which are relatively small compared to those of other substituted polyacetylenes. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 4546–4553, 1999     

Polymerization and polymer properties of (p-tert-butyl-o,o-dimethylphenyl)acetylene

(p-tert-Butyl-o,o-dimethylphenyl)acetylene (BDMPA) polymerized in high yields in the presence of W and Mo catalysts. Especially the W(CO)₆–CCl₄–hv catalyst quantitatively produced a polymer totally soluble in toluene and chloroform. The weight-average molecular weight of this polymer exceeded 2 × 10⁶. Poly(BDMPA) was a dark brown solid, and had alternating double bonds along the main chain. The weight loss of the polymer in air occurred only above 300°C, indicating a fairly high thermal stability. A free-standing film could be fabricated by solution casting. The electrical conductivity of the polymer at 25°C was 1 × 10⁻¹³ S cm⁻¹. The oxygen permeability coefficient and the separation factor of O₂ vs. N₂ of the polymer at 25°C were 67 barrers and 3.2, respectively. © 1996 John Wiley & Sons, Inc.     

Synthesis and properties of widely conjugated polyacetylenes having anthryl and phenanthryl pendant groups

The metathesis polymerization of 1- and 2-ethynylanthracenes (1-EA and 2-EA) and 2- and 3-ethynylphenanthrenes (2-EP and 3-EP) in the presence of various WCl₆-based catalysts produced widely conjugated soluble polymers with relatively high molecular weights. The highest weight-average molecular weights of poly(1-EA) and poly(2-EA) reached 61,000 and 26,000, respectively, when Ph₄Sn was used as cocatalyst, while those of poly(2-EP) and poly(3-EP) reached 23,000 and 65,000, respectively, with Ph₃Bi as cocatalyst. In contrast, MoCl₅-based catalysts were hardly or not effective for these monomers. A large red-shifted peak was observed centering at 570 nm (the cutoff at 750 nm) in the absorption spectrum of poly(1-EA), while the red-shifted peaks were seen around 500 nm (the cutoffs near 700 nm) in the spectra of other polymers, indicating wide conjugations of the polymer chains. The configurational structures of all the polymers confirmed by DSC and ¹H-NMR were trans structures. However, poly(1-EA) and poly(3-EP) appeared to consist partly of cis structures in their main chains. All of the present polymers showed relatively high thermal stability in air compared with poly(phenylacetylene). © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 3131–3137, 1998     

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,properties, and gas permeability of novel poly(diarylacetylene) derivatives

Poly(diphenylacetylene)s having various silyl groups are soluble in common solvents, from whose membranes poly(diphenylacetylene) membranes can be obtained by desilylation. The oxygen permeability coefficients of the desilylated polymers are quite different from one another (120–3300 barrers) irrespective of the same polymer structure. When bulkier silyl groups are removed, the oxygen permeability increases to larger extents. Poly[1-aryl-2-p-(trimethylsilyl)phenylacetylene]s are soluble in common solvents, and afford free-standing membranes. These Si-containing polymer membranes are desilylated to give the membranes of poly[1-aryl-2-phenylacetylene]s. Both of the starting and desilylated polymers show very high thermal stability and high gas permeability. 1-Phenyl-2-p-(t-butyldimethylsiloxy)phenylacetylene polymerizes into a high-molecular-weight polymer. This polymer is soluble in common organic solvents to provide a free-standing membrane. Desilylation of this membrane yields a poly(diphenylacetylene) having free hydroxyl groups, which is the first example of a highly polar group-carrying poly(diphenylacetylene). The P/P and P/P permselectivity ratios of poly(1-phenyl-2-p-hydroxylphenylacetylene) membrane are as large as 47.8 and 45.8, respectively, while keeping relatively high P of 110 barrers. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5028–5038, 2006     

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     

Polymerization of 1-chloro-2-β-naphthylacetylene by Mo catalysts and polymer properties

1-Chloro-2-β-naphthylacetylene (ClβNA) polymerized in good yields in the presence of MoCl₅-based catalysts. The highest weight-average molecular weight of poly(ClβNA) reached about 3 × 10⁵. The polymer was a yellow solid (absorption cutoff in CHCl₃ 450 nm). It was soluble in toluene, chloroform, etc., and provided a tough film by the solvent casting method. The polymer retained its weight up to 300°C in air; it was thermally less stable than poly(1-chloro-2-phenylacetylene) but more stable than poly(β-naphthylacetylene). The oxygen permeability coefficient (P_O2) of this polymer was 19 barrers (25°C), which is fairly small for a substituted polyacetylene. © 1996 John Wiley & Sons, Inc.     

Synthesis and properties of halogen- or methyl-containing poly(diphenylacetylene) membranes

Novel diphenylacetylenes with both trimethylsilyl groups and other substituents (R₂C₆H₃CCC₆H₄-p-SiMe₃, R = m,p-Cl,Cl, m,m-Cl,Cl, m,p-Br,Br, m,m-Br,Br, m,p-Me,Me, m,m-Me,Me, 1a–f, respectively) were polymerized with TaCl₅–n-Bu₄Sn to produce solvent-soluble polymers (2a–f). Most polymers (2a–e) had high molecular weight over 1 × 10⁶, and gave free-standing membranes by the solution casting method. Desilylation of these Si-containing polymer membranes was carried out with trifluoroacetic acid (TFA), which afforded solvent-insoluble desilylated polymer membranes (3a–e). According to thermogravimetric analysis (TGA), both Si-containing and desilylated polymers showed high thermal stability (T₀ ≥ 420 °C). The fractional free volume (FFV) of both Si-containing and desilylated polymer membranes (2a–d, 3a–d) were fairly large (ca. 0.27–0.32), while the FFVs of membranes (2e, 3e) were rather small (0.28 and 0.24). The oxygen permeability coefficients (P_O2) of 2a was as high as 5400 barrers, which is the largest among all the poly(diphenylacetylene) derivatives. Polymers 2b–d also exhibited high oxygen permeability, and their desilylated ones 3b–d retained similar high oxygen permeability. On the other hand, the P_O2 values of 2e and 3e were 1200 and 530 barrers, respectively, which are smaller than those of the halogen-containing polymers (2a–d and 3a–d).     

Synthesis of graft copolymer by ATRP of MMA from poly(phenylacetylene)

The present report describes the synthesis of a densely grafted copolymer consisting of a rigid main chain and flexible side chains by the atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) from an ATRP initiator‐bearing poly(phenylacetylene) [poly(BrPA)]. Poly(BrPA) was obtained by the polymerization of 4‐ethynylbenzyl‐2‐bromoisobutyrate using [Rh(NBD)Cl]₂ in the presence of Et₃N. The ¹H NMR spectrum showed that poly(BrPA) was in the cis‐transoid form. Upon heating at 30 °C for 24 h the cis‐transoid form was maintained. ATRP of MMA from the poly(BrPA) was carried out at 30 °C using CuX (X = Br, Cl) as the catalyst and N,N,N′,N′,N′‐pentamethyldiethylenetriamine as the ligand, and the resulting graft copolymers were investigated with ¹H NMR and SEC. To analyze the graft structure in more detail, the graft copolymers were hydrolyzed with KOH and the resultant poly(MMA) part was investigated with ¹H NMR and SEC. The polydispersity indexes of 1.25–1.45 indicated that the graft copolymers have well‐controlled side chains. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6697–6707, 2006     

Synthesis and characterization of poly(phenylacetylenes) featuring activated ester side groups

Four monomers based on 4‐ethynylbenzoic acid have been synthesized, one of those featuring an activated ester. With the metathesis catalytic system WCl₆/Ph₄Sn, these acetylenic monomers could successfully be polymerized yielding conjugated polymers with molecular weights of around 10,000 to 15,000 g/mol and molecular weight distributions M_w/M_n ≤ 2.1. Also the copolymerization of phenylacetylene or methyl 4‐ethynylbenzoate with pentafluorophenyl 4‐ethynylbenzoate as reactive unit was conducted. Polymer analogous reactions of the reactive polymers and copolymers with amines have been investigated and it was found that poly(pentafluorophenyl 4‐ethynylbenzoate) featured a significant reactivity, such that reactions proceeded quantitatively even with aromatic amines. Moreover the UV‐Vis spectra of the activated ester based polymer before and after conversion with aliphatic amines showed a change, indicating an effect on the conjugated backbone of the polymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Synthesis and characterization of thianthrene-containing poly(benzoxazole)s

New thioether- and thianthrene-containing poly(benzoxazole)s (PBOs) were synthesized from 4,4′-thiobis[3-chlorobenzoic acid] and thianthrene-2,7- and -2,8-dicarbonyl chlorides with commercially available bis-o-aminophenols. Polymers were prepared via solution polycondensation in poly(phosphoric acid) at 90–200°C. Transparent PBO films were cast directly from polymerization mixtures or m-cresol. The films were flexible and tough. Non-fluorinated PBOs were soluble only in strong acids and AlCl₃/NO₂R systems by forming complexes with the benzoxazole heterocycle Glass transition temperatures ranged from 298–450°C, and thermogravimetric analysis showed good thermal stabilities in both air and nitrogen atmospheres. © 1995 John Wiley & Sons, Inc.     

Influence of ortho‐substituents on the synthesis and properties of poly(phenylacetylene)s

The phenylacetylene derivatives (4‐decyloxyphenyl)acetylene ( M1 ), (4‐decyloxy‐2‐methylphenyl)acetylene ( M2 ), and (4‐decyloxy‐2,6‐dimethylphenyl)acetylene ( M3 ) were polymerized by the well‐defined Schrock‐type initiator Mo[N‐2,6‐i‐Pr₂C₆H₃)(CHCMe₂Ph)[OCMe(CF₃)₂]₂ ( I1 ) and by the ill‐defined quaternary system MoOCl₄–n‐Bu₄Sn–EtOH–quinuclidine (1:1:2:1) ( I2 ). Comparison of the compatibility of the initiators with the different monomers revealed a correlation of the size of the ortho‐substituents and the polymerizability of the monomers. M1 and M2 readily polymerized employing I1 , but conversion of the sterically demanding monomer M3 remained incomplete. However, the use of I2 led to high monomer conversions and polymer yields only in case of M2 and M3 . The steric bulkiness of the ortho‐substituents also decisively affected the maximum effective conjugation length (N_eff) of the polymers and hence their absorption maximum (λ_max) as well as their solution stability as shown by UV–vis and GPC studies, respectively. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4466–4477, 2004     

Gas transport properties of novel poly(arylene ether ketone)s containing dibenzoylbiphenyl and benzonaphthone moieties

In this work we present the results from studies on novel poly(arylene ether ketone)s, including gas permeability, wide-angle x-ray diffraction (WAXD), and dynamic mechanical analysis (DMA). Poly(arylene ether ketone)s containing 2,2′- and 3,3′-dibenzoylbiphenyl (DBBP) moieties were characterized to study the effect of biphenyl substitution on gas transport properties. Gas permeabilities of naphthalene-containing poly(arylene ether ketone)s were also measured. Higher permeabilities were observed for polymers prepared with 6F-BPA, compared to 9,9-bis(4-hydroxyphenyl)fluorene (HPF). The naphthalene-containing polymers exhibited higher permeabilities than the DBBP polymers, except for a polymer having the 2,2′-DBBP and tetramethylbiphenyl moieties. Based on our work, and results reported in the literature, the 3,3′-DBBP polymers showed the lowest permeabilities for DBBP-containing poly-(arylene ether ketone)s. The low permeabilities are due to more efficiently packed chains brought on by greater flexibility of the backbone, compared to the other polymers studied. DMA studies confirmed the higher barriers to rotation which are believed to be responsible for 2,2′-DBBP polymers having similar selectivities compared to 3,3′-DBBP polymers. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 425–431, 1998