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     

Copolymers of phenylacetylene and para‐nitrophenylacetylene with nonlinear optical properties: Further insight on the conformational structure

Copolymers of phenylacetylene (PA) and para‐nitrophenylacetylene (pNPA), named poly(PA‐co‐pNPA), were obtained in different PA/pNPA ratios and different reaction conditions with Rh(I) catalysts. The structure of the copolymers was investigated with IR, laser Raman, ¹H NMR, electron spin resonance (ESR), and diffuse reflective ultraviolet–visible (DRUV) light spectroscopies. The pristine polymers had a cis–transoidal structure as the predominant conformation with some trans sequences. Detailed ESR studies supported by computer simulation and conformation analysis have suggested that the trans sequences were due to pNPA sequences and that the cis‐C?C bond sequences of pNPA were associated with a stabilized cis radical formed by four to five of pNPA monomers. This particular stabilization was probably the reason for the higher reactivity of pNPA as compared with PA. These cis sequences were preferentially cleaved to generate π radicals. The compression and, to a minor extent, thermal treatment of poly(PA‐co‐pNPA) samples induced a cis‐to‐trans isomerization, leading to a trans–transoidal form with a planar zigzag structure and with a conjugation length up to n = 24 repeat units, determined by DRUV and Raman experiments. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2365–2376, 2004     

Convenient approach to novel functional substituted and branched poly(silylenemethylenes)

Novel poly(silylenemethylenes) have been prepared by the ring-opening polymerization of 1,3-disilacyclobutanes followed by a protodesilylation reaction with triflic acid. The silicon–aryl bond cleavage could be controlled by using different leaving groups, for instance phenyl- and para-anisyl substituents. The reactions of the triflate derivatives with organomagnesium compounds, LiAlH₄, amines, or alcohols gave functional substituted poly(silylenemethylenes). Hydrosilylation reactions or reductive coupling with potassium–graphite led to organosilicon network–polymers, which may serve as suitable precursors for silicon carbide and Si/C/N-based materials. The structures of the polymers were identified by NMR spectroscopy (²⁹Si, ¹³C, ¹H). © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 725–735, 1998     

Substituted polyacetylenes

This article reviews the chemistry of substituted polyacetylenes developed by our research group, more specifically, development of polymerization catalyst, synthesis of new polymers, elucidation of their structure, investigation of their properties, and development of their functions. The main features are as follows: a number of catalysts based on group 5, 6, and 9 transition metals (Nb, Ta, Mo, W, and Rh) have been developed, which include living polymerization catalysts. By using these catalysts, many new substituted polyacetylenes have been synthesized, whose molecular weights are very high (M_w = 10⁴?10⁶). Most of the polymers are soluble in many common solvents and stable enough in the air unlike polyacetylene. Some of these polymers exhibit interesting functions including high gas permeability and photoelectronic properties. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 165–180, 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     

Preparation and property of two soluble oxadiazole‐containing functional polyacetylenes

Two novel high‐molecular weight functional polyacetylenes (PA) bearing oxadiazole group as a pendant, poly(2‐(4‐octoxyphenyl)‐5‐(4‐ethynylphenyl)‐1,3,4‐oxadiazole) ( P1 ) and poly(2‐(4′‐octoxyphenyl)‐5‐(4′‐propynyloxyphenyl)‐1,3,4‐oxadiazole) ( P2 ) were synthesized by [Rh(nbd)Cl]₂‐Et₃N catalysts. Both polymers were soluble in common organic solvents such as CHCl₃ and tetrahydrofuran. Their structures and properties were characterized and evaluated with FTIR, NMR, UV, thermogravimetric analysis, GPC, optical‐limiting and nonlinear optical analyses, respectively. The results show that linkage of oxadiazole chromophore to PA main chain has improved the nonlinear optical (NLO) property of PA, and endowed PA with novel optical limiting properties and enhanced thermal stability. Simultaneously, the optical‐limiting and NLO properties of the polymers were sensitive to their molecular structures. P1 with oxadiazole directly incorporated into PA main chain as a pendant showed better performances and larger third‐order nonlinear optical susceptibility than P2 with oxadiazole incorporated into PA main chain via a spacer. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2072–2083, 2008     

Synthesis of novel polyaryl(ether–ketones) with tert-butyl pendent groups

Linear polyaryl(ether ketones) containing tert-butyl pendent groups were prepared from aromatic hydrocarbons and aromatic diacid chlorides, both classes of monomers containing tert-butyl pendent groups. The polymers were prepared in high yield and high molecular weight by low-temperature precipitation polycondensation in 1,2-dichloroethane. The presence of meta-oriented moieties and bulky pendent groups played a beneficial role with regard to solubility, while the thermal transitions and thermal resistance were not greatly impaired relative to conventional all para-oriented polyaryl(ether–ketones). The current polyaryl(ether–ketones) showed glass transition temperatures in the range 170–240°C and decomposition temperatures, as measured by TGA, of about 500°C. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1251–1256, 1998     

The synthesis of poly(phenylacetylene)s with bulky chiral silyl groups and the thermal stability of their helical conformation

The polymerization of (−)‐p‐[(tert‐butylmethylphenyl)silyl]phenylacetylene (t‐BuMePhSi*PA) and (+)‐p‐[{methyl(α‐naphthyl)phenyl}silyl]phenylacetylene (MeNpPhSi*PA) with the [(nbd)RhCl]₂ Et₃N catalyst yielded polymers with very high molecular weights over 2 × 10⁶ in high yields. The optical rotations of the formed poly(t‐BuMePhSi*PA) and poly(MeNpPhSi*PA) were as high as −356 and −150° (c = 0.11 g/dL in CHCl₃), respectively. The circular dichroism (CD) spectrum of poly(t‐BuMePhSi*PA) in CHCl₃ exhibited very large molar ellipticities ([θ]) in the UV region: [θ]_max = 9.2 × 10⁴ ° · cm² · dmol⁻¹ at 330 nm and −8.0 × 10⁴ ° · cm² · dmol⁻¹ at 370 nm. The [θ]_max values of poly(MeNpPhSi*PA) were also fairly large: [θ]_max = 7.1 × 10⁴ ° · cm² · dmol⁻¹ at 330 nm and −5.3 × 10⁴ ° · cm² · dmol⁻¹ at 370 nm. The optical rotations of poly(t‐BuMePhSi*PA) and poly(MeNpPhSi*PA), measured in tetrahydrofuran, chloroform, and toluene solutions, were hardly dependent on temperature in the range 22–65 °C. The CD effects of these polymers hardly changed in the temperature range 28–80 °C, either. These results indicate that the helical structures of these polymers are thermally appreciably stable. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 71–77, 2001     

Synthesis and fluorescent properties of model compounds for conjugated polymer containing maleimide units at the main chain

2,3‐Diaryl substituted maleimides as model compounds of conjugated maleimide polymers [poly(RMI‐alt‐Ar) and poly(RMI‐co‐Ar)] were synthesized from 2,3‐dibromo‐N‐substituted maleimide (DBrRMI) [R= cyclohexyl (DBrCHMI) and n‐hexyl (DBrHMI)] and aryl boronic acid using palladium catalysts. To clarify structures of conjugated polymer containing maleimide units at the main chain, ¹³C NMR spectra of 2‐aryl or 2,3‐diaryl substituted maleimides were compared with those of N‐substituted maleimide polymers. Copolymers obtained with DBrRMI via Suzuki‐Miyaura cross‐coupling polymerizations or Yamamoto coupling polymerizations were dehalogenated structures at the terminal end. This dehalogenation may contribute to the low polymerizability of DBrRMIs. On the other hand, the π‐conjugated compounds showed high solubility in common organic solvents. The N‐substituents of maleimide cannot significantly affect the photoluminescence spectra of 2,3‐diaryl substituted maleimides derivatives. The fluorescence spectra of poly(RMI‐alt‐Ar) and poly(RMI‐co‐Ar) varied with N‐substituents of the maleimide ring. When exposed to ultraviolet light of wavelength 352 nm, a series of 1,4‐phenylene‐ and/or 2,5‐thienylene‐based copolymers containing N‐substituted maleimide derivatives fluoresced in a yellow to blue color. It was found that photoluminescence emissions and electronic state of π‐conjugated maleimide derivatives were controlled by aryl‐ and N‐substituents, and maleimide sequences of copolymers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Synthesis of poly(1‐chloro‐2‐arylacetylene)s with high cis‐content and examination of their absorption/emission properties

A series of 1‐chloro‐2‐arylacetylenes [Cl‐C?C‐Ar, Ar = C₆H₅ ( 1 ), C₆H₄‐p‐i Pr ( 2 ), C₆H₄‐p‐Oi Pr ( 3 ), C₆H₄‐p‐NHC(O)Ot Bu ( 4 ), and C₆H₄‐o‐i Pr ( 5 )] were polymerized using (tBu₃P)PdMeCl/silver trifluoromethanesulfonate (AgOTf) and MoCl₅/SnBu₄ catalysts. The corresponding polymers [poly( 1 )–poly( 5 )] with weight‐average molecular weights of 6,500–690,000 were obtained in 10–91% yields. THF‐insoluble parts, presumably high‐molecular weight polymers, were formed together with THF‐soluble polymers by the Pd‐catalyzed polymerization. The Pd catalyst polymerized nonpolar monomers 1 and 2 to give the polymers in yields lower than the Mo catalyst, while the Pd catalyst polymerized polar monomers 3 and 4 to give the corresponding polymers in higher yields. The ¹H NMR and UV–vis absorption spectra of the polymers indicated that the cis‐contents of the Pd‐based polymers were higher than those of the Mo‐based polymers, and the conjugation length of the Pd‐based polymers was shorter than that of the Mo‐based polymers. Pd‐based poly( 5 ) emitted fluorescence most strongly among poly( 1 )–poly( 5 ). © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55 , 382–388     

Synthesis,functionalization and crosslinking reactions of poly(silylenemethylene)s

Novel poly(silylenemethylene)s have been prepared by the ring‐opening polymerization of 1,3‐disilacyclobutanes followed by a protodesilylation reaction with triflic acid. The silicon–aryl bond cleavage could be controlled by using different leaving groups, for instance phenyl‐ and para‐anisyl substituents. The reactions of the triflate derivatives with organomagnesium compounds, LiAlH₄, amines or alcohols gave functional substituted poly(silylenemethylene)s. Hydrosilylation reactions or reductive coupling with potassium–graphite led to organosilicon network‐polymers, which may serve as suitable precursors for silicon carbide and Si/C/N‐based materials. The structures of the polymers were identified by nuclear magnetic resonance spectroscopy (²⁹Si, ¹³C, ¹H). Copyright © 1999 John Wiley & Sons, Ltd.     

Novel isolated,L‐amino acid‐ligated rhodium catalysts that induce highly helix‐sense‐selective polymerization of an achiral 3,4,5‐trisubstituted phenylacetylene

Two novel chiral well‐defined rhodium complexes, Rh(cod)(L‐Phe) (cod = 1,5‐cyclooctadiene, Phe = phenylalanine) and Rh(cod)(L‐Val) (Val = valine) were synthesized, isolated by recrystallization, and characterized. The helix‐sense‐selective polymerization (HSSP) of an achiral 3,4,5‐trisubstituted phenylacetylene, p‐dodecyloxy‐m,m‐dihydroxyphenylacetylene (DoDHPA) was examined by using the two Rh complexes as catalysts. These catalysts provided high molecular weight polymers (M_w 28 × 10⁴?45 × 10⁴) in about 40%–85% yields. The resulting polymers exhibited a bisignated CD signal at about 300 nm and a broad signal around 470 nm, indicating that they have preferential one‐handed helical structure. The present catalysts achieved larger molar ellipticity up to [θ]₃₁₀ = 13.0 × 10⁴ deg cm²/dmol than those with binary chiral catalytic systems, [Rh(cod)Cl]₂/(L‐phenylalaninol), [Rh(cod)Cl]₂/(L‐valinol), and [Rh(nbd)Cl]₂/(R)‐PEA. All these results manifest that the present, well‐defined Rh complexes serve as excellent catalysts for the HSSP of DoDHPA. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2346–2351     

Solution processable polyamides containing thiazole units and thioether linkages with high optical transparency,high refractive index,and low birefringence

A series of new organic‐soluble polyamides (PAs) bearing flexible thioether linkages and heteroaromatic thiazole units were synthesized from a novel thioether‐bridged diamine monomer (DA) and various commercially available aromatic dicarboxylic acids (1–5) via a direct polycondensation method. The resulting polymers were obtained in high yields and possessed inherent viscosities in the range of 0.41–0.80 dL g^?1. All of the polymers were amorphous in nature, exhibited good solubility and could be easily dissolved in amide‐type polar aprotic solvents and even dissolved in less polar solvents (e.g., tetrahydrofuran, pyridine, and acetone). They showed excellent thermal stability with glass transition temperatures between 207 and 239 °C and 10% weight loss temperatures in excess of 424 °C in nitrogen and 469 °C in air atmosphere. The optical transmittances of the PA films at 450 nm were higher than 85% for the thickness of ～10 μm. The combination of the thiazole moieties and flexible thioether linkages provided PAs with high average refractive indices (n_av) of 1.7414–1.7542 and low birefringences (Δn) of 0.0061–0.0087 at 632.8 nm. In particular, the n_av of PA‐5 derived from DA and 2,2′‐dithiodibenzoic acid exhibited the highest refractive index (1.7542) in the high refractive index PAs. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 3505–3515     

Synthesis and properties of polyimides derived from 1,4-bis(4-aminophenoxy)2,5-di-tert-butylbenzene

Novel aromatic polyimides containing symmetric, bulky di-tert-butyl substituents unit were synthesized from 1,4-bis(4-aminophenoxy)2,5-di-tert-butylbenzene (BADTB) and various aromatic tetracarboxylic dianhydrides by the conventional two-stage procedure that included ring-opening polyaddition in a polar solvent such as N,N-dimethylacetamide to give poly(amic acid)s, followed by cyclodehydration to polyimides. The diamine was prepared through the nucleophilic displacement of 2,5-di-tert-butylhydroquinone with p-chloronitrobenzene in the presence of K₂CO₃, followed by catalytic reduction. Depending on the dianhydrides used, the poly(amic acid)s obtained had inherent viscosities of 0.83–1.88 dL g⁻¹. Most of the polyimides formed transparent, flexible, and tough films. Tensile strength and elongation at break of the BADTB-based polyimide films ranged from 68–93 MPa and 7–11%, respectively. The polyimide derived from 4,4′-hexafluoro-isopropylidenebisphathalic anhydride had better solubility than the other polyimides. These polyimides had glass transition temperatures between 242–298°C and 10% mass loss temperatures were recorded in the range of 481–520°C in nitrogen. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1527–1534, 1997     

Polymerization of vinyl ethers with transition‐metal catalysts: An examination of the stereoregularity of the formed polymers

The polymerization of isobutyl vinyl ether (IBVE) and tert‐butyl vinyl ether (TBVE) was carried out with metallocene and nonmetallocene catalysts, and the stereoregularity of the formed polymers was examined with ¹³C NMR spectroscopy. IBVE afforded polymers with 63–68% dyad isotacticity by polymerization with mixtures of metallocene catalysts and methyl aluminoxane as a cocatalyst in toluene as a solvent. However, TBVE yielded polymers with 47–52% dyad isotacticity (21–28% triad isotacticity) under the same conditions, the isotacticity being lower than that of poly(isobutyl vinyl ether) (PIBVE). Nonmetallocene catalysts, including Ti, Zr, and Hf complexes with two phenoxy imine chelate ligands, provided PIBVE and poly(tert‐butyl vinyl ether) with 63–68 and 45–51% dyad isotacticity, respectively. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3938–3943, 2002     

Polymerization of optically active disubstituted acetylene monomers by Pd catalyst bearing bulky phosphine ligand

Chloro- and aryl-substituted acetylene monomers having an optically active group were polymerized by a Pd catalyst [(^tBu₃P)PdMeCl] bearing a bulky phosphine ligand, and by MoCl₅ for comparison. The corresponding disubstituted acetylene polymers with M_n's = 2000–19,500 and 6900–10,800 were obtained in 29–83% and 11–62% yields when the Pd and Mo catalysts were used, respectively. The formation of polyacetylenes, poly[(R)- 1p ], poly[(R)- 1m ], and poly[(S)- 2p ] were confirmed by SEC and the presence of a Raman scattering peak based on the alternating double bonds of the main chain. Pd-based poly[(R)- 1m ] exhibited CD signals around 350 nm assignable to a certain secondary structure, while Mo-based poly[(R)- 1m ] did not. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3011–3016     

Synthesis and properties of poly(phenylacetylenes) having two polar groups or one cyclic polar group on the phenyl ring

Phenylacetylene (PA) derivatives having two polar groups (ester, 2a – d ; amide, 4) or one cyclic polar group (imide, 5a – c ) were polymerized using (nbd)Rh⁺[(η⁶‐C₆H₅)B^?(C₆H₅)₃] catalyst to afford high molecular weight polymers (～1 × 10⁶ – 4 × 10⁶). The hydrolysis of ester‐containing poly(PA), poly( 2a) , provided poly(3,4‐dicarboxyPA) [poly ( 3 )], which could not be obtained directly by the polymerization of the corresponding monomer. The solubility properties of the present polymers were different from those of poly(PA) having no polar group; that is, poly( 2a )–poly( 2d ) dissolved in ethyl acetate and poly( 4 ) dissolved in N,N‐dimethylformamide, while poly(PA) was insoluble in such solvents. Ester‐group‐containing polymers [poly( 2a )–poly( 2d )] afforded free‐standing membranes by casting from THF solutions. The membrane of poly( 2a ) showed high carbon dioxide permselectivity against nitrogen (PCO₂/PN₂ = 62). © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5943–5953, 2006     

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     

Design,Synthesis, and Properties of Substituted Polyacetylenes

This article reviews recent topics on the polymerization of substituted acetylenes, focusing on the synthesis of poly(diphenylacetylenes) and the living polymerization of phenylacetylenes. Diphenylacetylene (DPA) polymerizes with TaCl_s-n-Bu₄Sn to give a polymer which is thermally very stable but insoluble in any solvents. DPAs with various groups (e.g.,p-Me₃Si,m-Me₃Ge, p-t-Bu,and_p-PhO) polymerize similarly. These polymers are soluble and their M¯_w's reach 1 × 10⁶ to 3 × 10⁶. Some of them are more gas-permeable than poly(dimethylsiloxane). Several acetylenes (e.g., ClC -n-C₆H₁₃ and HCUC-t-Bu) have been found to undergo living polymerization with MoOCl₄-n-Bu₄Sn-EtOH. Whereas phenylacetylene (PA) does not polymerize in a living fashion, ortho-substituents in PA more or less suppress termination and chain transfer. PAs with bulky ortho groups (e.g., CF₃ and Me₃Ge) especially undergo virtually ideal living polymerization.     

High refractive index materials: A structural property comparison of sulfide‐ and sulfoxide‐containing polyamides

High‐refractive‐index polyamides (PAs) are developed by incorporation of sulfide‐ or sulfoxide linkages and chlorine substituents. The PAs are synthesized through the polycondensation of two novel diamine monomers, 2,2′‐sulfide‐bis(4‐chloro‐1‐(4‐aminophenoxy) phenyl ether (3a) and 2,2′‐sulfoxide‐bis(4‐chloro‐1‐(4‐aminophenoxy) phenyl ether (3b), with various aromatic diacids (a–e). The ortho‐sulfide or sulfoxide units, pendant chlorine groups, and flexible ether linkages in the diamine monomers endowed the obtained PAs with excellent solubilities in organic solvents. The resulting PAs showed high thermal stability, with 10% weight loss temperatures exceeding 415 °C under nitrogen and 399 °C in air atmosphere. The combination of chlorine substituents, sulfide or sulfoxide linkages, and ortho‐catenated structures provided polymers with high transparency along with high refractive index values of up to 1.7401 at 632.8 nm and low birefringences (<0.0075). The structure–property relationships of the analogous PAs containing sulfide or sulfoxide linkages were also studied in detail by comparing the results. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2867–2877