α‐Propargyl amino acid‐derived optically active novel substituted polyacetylenes: Synthesis,secondary structures,and responsiveness to ions

Novel optically active substituted acetylenes HC? CCH₂CR¹(CO₂CH₃)NHR² [(S)‐/(R)‐ 1 : R¹ = H, R² = Boc, (S)‐ 2 : R¹ = CH₃, R² = Boc, (S)‐ 3 : R¹ = H, R² = Fmoc, (S)‐ 4 : R¹ = CH₃, R² = Fmoc (Boc = tert‐butoxycarbonyl, Fmoc = 9‐fluorenylmethoxycarbonyl)] were synthesized from α‐propargylglycine and α‐propargylalanine, and polymerized with a rhodium catalyst to provide the polymers with number‐average molecular weights of 2400–38,900 in good yields. Polarimetric, circular dichroism (CD), and UV–vis spectroscopic analyses indicated that poly[(S)‐ 1 ], poly[(R)‐ 1 ], and poly[(S)‐ 4 ] formed predominantly one‐handed helical structures both in polar and nonpolar solvents. Poly[(S)‐ 1a ] carrying unprotected carboxy groups was obtained by alkaline hydrolysis of poly[(S)‐ 1 ], and poly[(S)‐ 4b ] carrying unprotected amino groups was obtained by removal of Fmoc groups of poly[(S)‐ 4 ] using piperidine. Poly[(S)‐ 1a ] and poly[(S)‐ 4b ] also exhibited clear CD signals, which were different from those of the precursors, poly[(S)‐ 1 ] and poly[(S)‐ 4 ]. The solution‐state IR measurement revealed the presence of intramolecular hydrogen bonding between the carbamate groups of poly[(S)‐ 1 ] and poly[(S)‐ 1a ]. The plus CD signal of poly[(S)‐ 1a ] turned into minus one on addition of alkali hydroxides and tetrabutylammonium fluoride, accompanying the red‐shift of λ_max. The degree of λ_max shift became large as the size of cation of the additive. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Synthesis,Characterization, and thermoresponsive properties of Helical Polypeptides Derivatized from Poly(γ−4‐(3‐chloropropoxycarbonyl)benzyl‐L‐glutamate)

A series of side‐chain‐functionalized α‐helical polypeptides, i.e., poly(γ‐4‐(3‐chloropropoxycarbonyl)benzyl‐_L‐glutamate) (6) have been prepared from n‐butylamine initiated ring‐opening polymerization (ROP) of γ‐4‐(3‐chloropropoxycarbonyl)benzyl‐_L‐glutamic acid‐based N‐carboxyanhydride. Polypeptides bearing oligo‐ethylene‐glycol (OEG) groups or 1‐butylimidazolium salts were prepared from 6 via copper‐mediated [2+3] alkyne‐azide 1,3‐dipolar cycloaddition or nuleophilic substitution, respectively. CD and FTIR analysis revealed that the polymers adopt α‐helical conformations both in solution and the solid state. Polymers bearing OEG (m = 3) side‐chains showed reversible LCST‐type phase transition behaviors in water while polymers bearing 1‐butylimidazolium and I^? counter‐anions exhibited reversible UCST‐type transitions in water. Variable‐temperature UV‐vis analysis revealed that the phase transition temperatures (T_pts) were dependent on the main‐chain length and polymeric concentration. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2469–2480     

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 of well‐defined 7‐arm and 21‐arm poly(N‐isopropylacrylamide) star polymers with β‐cyclodextrin cores via click chemistry and their thermal phase transition behavior in aqueous solution

The syntheses of well‐defined 7‐arm and 21‐arm poly(N‐isopropylacrylamide) (PNIPAM) star polymers possessing β‐cyclodextrin (β‐CD) cores were achieved via the combination of atom transfer radical polymerization (ATRP) and click reactions. Heptakis(6‐deoxy‐6‐azido)‐β‐cyclodextrin and heptakis[2,3,6‐tri‐O‐(2‐azidopropionyl)]‐β‐cyclodextrin, β‐CD‐(N₃)₇ and β‐CD‐(N₃)₂₁, precursors were prepared and thoroughly characterized by nuclear magnetic resonance and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry. A series of alkynyl terminally functionalized PNIPAM (alkyne‐PNIPAM) linear precursors with varying degrees of polymerization (DP) were synthesized via atom transfer radical polymerization (ATRP) of N‐isopropylacrylamide using propargyl 2‐chloropropionate as the initiator. The subsequent click reactions of alkyne‐PNIPAM with β‐CD‐(N₃)₇ and β‐CD‐(N₃)₂₁ led to the facile preparation of well‐defined 7‐arm and 21‐arm star polymers, namely β‐CD‐(PNIPAM)₇ and β‐CD‐(PNIPAM)₂₁. The thermal phase transition behavior of 7‐arm and 21‐arm star polymers with varying molecular weights were examined by temperature‐dependent turbidity and micro‐differential scanning calorimetry, and the results were compared to those of linear PNIPAM precursors. The anchoring of PNIPAM chain terminal to β‐CD cores and high local chain density for star polymers contributed to their considerably lower critical phase separation temperatures (T_c) and enthalpy changes during phase transition as compared with that of linear precursors. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 404–419, 2009     

Synthesis and properties of optically active amino acid based polyacetylenes bearing eugenol and fluorene moieties

Novel optically active amino acid based polyacetylenes bearing eugenol and fluorene moieties were synthesized, and their properties, including chiroptical ones, were analyzed. N‐[1‐(3,4‐Dimethoxyphenyl)‐2‐propyloxycarbonyl]‐L ‐alanine N′‐propargylamide ( 1 ), N‐[1‐(3,4‐dimethoxyphenyl)‐2‐propyloxycarbonyl]‐L ‐alanine propargyl ester ( 2 ), N‐(9‐fluorenylmethoxycarbonyl)‐L ‐alanine N′‐propargylamide ( 3 ), and N‐(9‐fluorenylmethoxycarbonyl)‐L ‐alanine propargyl ester ( 4 ) were polymerized with a rhodium‐zwitterion catalyst in tetrahydrofuran to afford the corresponding polymers with moderate molecular weights ranging from 10,800 to 17,300 in good yields. Because of the large specific rotation and circular dichroism (CD) signal, it was concluded that the poly(N‐propargylamide)s [poly( 1 ) and poly( 3 )] took a helical structure with a predominantly one‐handed screw sense. The solvent and temperature could tune the helical structure of poly( 1 ). On the other hand, the poly(propargyl ester)s [poly( 2 ) and poly( 4 )] exhibited only small specific rotations and CD signals. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 810–819, 2006     

Synthesis and structural characterization of novel,fluorinated poly(phthalazinone ether)s containing perfluorophenylene moieties

The synthesis and structural characterization of a series of novel, fluorinated poly(phthalazinone ether)s containing perfluorophenylene moieties are described. The monomers, 4‐(4′‐hydroxyaryl)phthalazin‐1(2H)‐ones ( 2a – 2d ), were conveniently and efficiently synthesized from phenols and phthalic anhydride in two steps via 2‐(4′‐hydroxybenzoyl)benzoic acids, which were first obtained by the Friedel–Crafts reaction in good yields and with high stereoselectivity and were then converted into 2a – 2d by fusion with hydrazine. All the polymers were prepared by nucleophilic aromatic substitution (S_NAr) polycondensation between the compounds perfluorobiphenyl and 4‐(4′‐hydroxyaryl)phthalazin‐1(2H)‐ones ( 2a ‐ 2d ). The resulting fluorinated polymers were readily soluble in common organic solvents (e.g., CHCl₃, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, N‐methylpyrrolidone, etc.) at room temperature. Their weight‐average molecular weights and the polydispersities ranged from (7.96–18.25) × 10³ to 1.31–2.71, respectively. Their glass‐transition temperatures varied from 213 to 263 °C. They were all stable up to 390 °C both in air and in argon. The 5% weight‐loss temperatures of these polymers in air and argon ranged from 393–487 to 437–509 °C, respectively. Wide‐angle X‐ray diffraction studies indicated they were all amorphous and could be attributed to the presence of kink nonplanar moiety, phenyl phthalazinone along the polymer backbone. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 925–932, 2004     

Second harmonic generation in polymers containing a new azo chromophore based on phenylnitrobenzoxazole

The synthesis of the new chromophores 2‐{4‐[4‐(N,N‐dihydroxyethylamino)‐phenylazo]‐phenyl}‐6‐nitrobenzoxazole ( 1 ) and 4‐[4‐(N,N‐dihydroxyethylamino)phenylazo]‐benzoic acid ( 2 ) is described. Three homopolymers obtained by the polycondensation of 1 with propyloxy‐terephthalic acid and 1 and 2 with 2,4‐tolylenediisocianate as well as two copolymers obtained by polycondensation of appropriate mixtures of chromophores 1 and 2 with 2,4‐tolylene‐diisocianate were prepared and characterized. All as‐prepared polymers but one (homopolyurethane of 1 ) were amorphous and exhibited good optical clarity, good thermal stability above the glass transition, and solubility in organic solvents. The second‐order nonlinear optical behavior of the amorphous polymers was investigated on spin‐coated corona‐poled films through second harmonic generation (SHG) experiments at 1064 nm. At this wavelength, resonance‐enhanced values of the SHG coefficient d₃₃ were found in the range between 6 and 34 pm/V where higher values were observed for polymers with a higher molar content of 1 . © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1468–1475, 2002     

Synthesis,photoluminescence, and electrochromism of novel aromatic poly(amine‐1,3,4‐oxadiazole)s bearing anthrylamine chromophores

Two novel poly(amine‐hydrazide)s were prepared from the polycondensation reactions of the dicarboxylic acid, 9‐[N,N‐di(4‐carboxyphenyl)amino]anthracene ( 1 ), with terephthalic dihydrazide ( TPH ) and isophthalic dihydrazide ( IPH ) via the Yamazaki phosphorylation reaction, respectively. The poly(amine‐hydrazide)s were readily soluble in many common organic solvents and could be solution cast into transparent films. Differential scanning calorimetry (DSC) indicated that these hydrazide polymers had glass‐transition temperatures (T_g) in the range of 182–230 °C and could be thermally cyclodehydrated into the corresponding oxadiazole polymers in the range of 300–400 °C. The resulting poly(amine‐1,3,4‐oxadiazole)s had useful levels of thermal stability associated with high T_g (263–318 °C), 10% weight‐loss temperatures in excess of 500 °C, and char yield at 800 °C in nitrogen higher than 55%. These organo‐soluble anthrylamine‐based poly(amine‐hydrazide)s and poly (amine‐1,3,4‐oxadiazole)s exhibited maximum UV‐vis absorption at 346–349 and 379–388 nm in N‐methyl‐2‐pyrrolidone (NMP) solution, respectively. Their photoluminescence spectra in NMP solution showed maximum bands around 490–497 nm in the green region. The poly(amine‐hydrazide) I ‐ IPH showed a green photoluminescence at 490 nm with PL quantum yield of 29.9% and 17.0% in NMP solution and film state, respectively. The anthrylamine‐based poly(amine‐1,3,4‐oxadiazole)s revealed a electrochromic characteristics with changing color from the pale yellow neutral form to the red reduced form when scanning potentials negatively from 0.00 to ?2.20 V. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1584–1594, 2009     

Synthesis and properties of blue light‐emitting,silicon‐containing,regio‐ and stereoregular conjugated polymers

This article concerns the hydrosilylation polyaddition of 1,4‐bis(dimethylsilyl)benzene ( 1 ) with 4,4′‐diethynylbiphenyl, 2,7‐diethynylfluorene ( 2b ), and 2,6‐diethynylnaphthalene with RhI(PPh₃)₃ catalyst. Trans‐rich polymers with weight‐average molecular weights (M_w's) ranging from 19,000 to 25,000 were obtained by polyaddition in o‐Cl₂C₆H₄ at 150–180 °C, whereas cis‐rich polymers with M_w's from 4300 to 34,000 were obtained in toluene at 0 °C–r.t. These polymers emitted blue light in 4–81% quantum yields. The cis polymers isomerized into trans polymers upon UV irradiation, whereas the trans polymers did not. The device having a layer of polymer trans‐ 3b obtained from 1 and 2b demonstrated electroluminescence without any dopant. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2774–2783, 2004     

Synthesis and properties of carbamate‐ and amine‐containing poly(phenylacetylenes)

The 3‐ and 4‐aminophenylacetylenes protected by t‐butoxycarbonyl (t‐Boc) and 9‐fluorenylmethoxycarbonyl (Fmoc) groups ( 3a – 6a ) were synthesized and polymerized using [(nbd)RhCl]₂ ( 1 ) and [(nbd)Rh⁺‐η⁶‐PhB^?Ph₃] ( 2 ) catalysts. The t‐Boc‐containing polymers [poly( 3a ) and poly( 4a )] were obtained in high yield (82–91%). Among the Fmoc‐protected monomers, the para‐derivative polymerized well [poly( 6a ); yield = 85–94%], whereas its meta‐substituted analogue did not afford high molecular weight polymer in good yield [poly( 5a ); yield = 10–15%]. The use of KN(SiMe₃)₂ as a cocatalyst in conjunction with 1 led to a dramatic increase in the molecular weight of the polymers. The acid‐ and base‐catalyzed removal of the t‐Boc and the Fmoc groups, respectively, generated primary amine‐containing polymers [poly( 3b )–poly( 6b )] which cannot be obtained directly by the polymerization of the corresponding monomers. The solubility characteristics of the polymers bearing protected amino groups were quite different from those of the unprotected ones, the former being soluble in polar solvents, whereas the latter displayed poor solubility even in polar protic or highly polar aprotic solvents. The attempts to accomplish the free‐standing membrane fabrication by solution casting were successful only for poly( 3a ), and an augmentation in the gas permeability and CO₂/N₂ permselectivity was discerned in comparison with the unsubstituted poly(phenylacetylene) and poly(m‐t‐butyldimethylsiloxyphenylacetylene). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1853–1863, 2009     

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     

Assemblies of 1D and 2D Copper(II) Chiral Coordination Polymers by Salicylaldehyde Schiff Bases: Synthesis,Crystal Structures,and Magnetic Properties

Reaction of CuCl₂ · 2H₂O with chiral Schiff bases and sodium dicyanamide led to the formation of two chiral copper(II) coordination polymers, namely [Cu₄(L¹)₂(dca)₄]_n ( 1 ) and [Cu₂(L²)(μ‐Cl)(dca)(H₂O)]_n · nH₂O ( 2 ) {H₂L¹ = (1R, 3S)‐N′,N′′‐bis[salicylidene]‐1,3‐diamino‐ 1,2,2‐trimethylcyclopentane, H₂L² = (1R, 3S)‐N′,N′′‐bis[3‐ethoxysalicylidene]‐1,3‐diamino‐ 1,2,2‐trimethylcyclopentane, dca = dicyanamide}. Both complexes were structurally characterized by elemental analyses, IR spectroscopy and single‐crystal X‐ray diffraction. Complex 1 exhibits a two‐dimensional polymeric structure formed by single dca bridging tetranuclear Cu₄ units. Complex 2 displays a left‐handed helical chain structure constructed from Cu₂ dimers with single dca bridges. The chirality of 1 and 2 was confirmed by circular dichroism (CD) measurements in solution. Both complexes exhibit strong antiferromagnetic couplings with J = –308(4) cm^–1 for 1 and J = –123(1) cm^–1 for 2 in 2–300 K.     

Synthesis and UCST‐type phase behavior of OEGylated poly(γ‐benzyl‐l‐glutamate) in organic media

A series of OEGylated poly(γ‐benzyl‐l ‐glutamate) with different oligo‐ethylene‐glycol side‐chain length, molecular weight (MW = 8.4 × 10³ to 13.5 × 10⁴) and narrow molecular weight distribution (PDI = 1.12–1.19) can be readily prepared from triethylamine initiated ring‐opening polymerization of OEGylated γ‐benzyl‐l ‐glutamic acid based N‐carboxyanhydride. FTIR analysis revealed that the polymers adopted α‐helical conformation in the solid‐state. While they showed poor solubility in water, they exhibited a reversible upper critical solution temperature (UCST)‐type phase behavior in various alcoholic organic solvents (i.e., methanol, ethanol, 1‐propanol, 1‐butanol, 1‐pentanol, and isopropanol). Variable‐temperature UV–vis analysis revealed that the UCST‐type transition temperatures (T_pts) of the resulting polymers were highly dependent on the type of solvent, polymer concentration, side‐ and main‐chain length. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1348‐1356     

Deep insights into the hydrolysis of N,N‐dialkylaminoethyl methacrylates in aqueous solution with 1H NMR spectroscopy

N,N‐dialkylaminoethyl methacrylate (DAEA) monomers are extensively used to prepare multi‐responsive polymers. However, these monomers face high risk of hydrolysis in their ester groups when being polymerized in water‐containing medias. Here, NMR spectroscopy was employed to continuously track the hydrolysis and solubility of four widely used DAEA monomers [CH₂CH₂R₁COO(CH₂)₂N(R₂)₂; R₁ = H or CH₃; R₂ = CH₃, CH₂CH₃ or CH(CH₃)₂] under typical polymerization conditions. With this technique, the hydrolysis reactivity and absolute hydrolysis amount of these monomers are separately examined, and then their kinetic correlations with solubility, molecular structure, pH, and temperature are established, so that the hydrolysis of DAEA monomers and even other esters with similar cyclic structure can be predicted. The present efforts are expected to provide a general understanding for the hydrolysis of all the DAEA monomers, benefitting to the optimization of polymerization toward well‐defined DAEA copolymers, as well as the design of smart soft matter for specific applications. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 914–923     

Synthesis of optically active conjugated polymers containing platinum in the main chain: Control of the higher‐order structures by substituents and solvents

The Sonogashira–Hagihara coupling polymerization of d ‐hydroxyphenylglycine‐derived diiodo monomers 1–4 and platinum‐containing diethynyl monomer 5 gave the corresponding polymers [poly( 1–5 )–( 2–5 )] with number‐average molecular weights of 19,000–25,000 quantitatively. The polymers were soluble in CHCl₃, CH₂Cl₂, THF, and DMF. CD and UV–vis spectroscopic analysis revealed that amide‐substituted polymers [poly( 1–5 ) and poly( 2–5 )] formed chiral higher‐order structures in solution, while ester‐substituted polymers [poly( 3–5 ) and poly( 4–5 )] did not. Poly( 1–5 ) formed one‐handed helices in THF/toluene mixtures, while it formed chiral aggregates in THF/MeOH mixtures. Poly( 1–5 ) emitted fluorescence with quantum yields ranging from 0.8 to 1.3%. The polymers usually aggregated in the solid state. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2452–2461     

Synthesis,optical, and electrochemical properties of novel copolymers on the basis of benzothiadiazole and electron‐rich arene units

Novel alternating conjugated copolymers ( P1–P6 ) consisting of an electron‐deficient benzothiadiazole and a variety of electron‐rich thiophene‐arene‐thiophene units were synthesized by palladium‐catalyzed polycondensations (Stille and Suzuki reactions), aiming at processable materials with a reduced optical band gap. The structures of P1–P6 were confirmed by ¹H NMR and ¹³C NMR, and their molecular weights were determined by size exclusion chromatography. In the Suzuki polycondensation, the role of the catalyst [Pd(PPh₃)₄ and Pd(OAc)₂] on the resulting molecular weight was investigated. Pd(OAc)₂ enhances the molecular weight of the polymers for both thiophene and phenylene bis‐boronic esters as compared with Pd(PPh₃)₄. The optical properties of the polymers were examined in solution and the solid state. The polymers with n‐octyl substituents ( P1 , P4 , P5 , and P6 ) on the thiophene rings possessed less‐planar structures as a result of torsional steric hindrance, and their absorption spectra appeared blueshifted as compared with their unsubstituted analogues ( P2 and P3 ). The electrochemical properties of the polymers were studied using cyclic voltammetry. Although the alkyl substitution affects the oxidation potential, only marginal differences in the reduction potentials were observed. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2360–2372, 2002     

Synthesis,structural, and retrostructural analysis of helical dendronized poly(1‐naphthylacetylene)s

Structural and retrostructural analysis of chiral, nonracemic ( poly [(3,4,5)dm8G1‐1EN] ), and achiral ( poly[(3,4,5)12G1‐1EN] ) poly(1‐naphthylacetylene)s demonstrates new design principles for helical dendronized polyarylacetylenes. The oblate cylindrical dendronized polymers self‐organize in a c2mm centered rectangular columnar (Φ_r‐c) lattice. An all cis‐polyene backbone microstructure with very high cisoid character is introduced to rationalize features from small‐ and wide‐angle X‐ray diffraction experiments. More compact helical conformations are ideal for efficient communication or amplification of chirality over long distances. Peripheral chiral tails select a preferred helical screw sense of the polyene backbone. In solution, the preferred helical conformation persists over a wide temperature range. In bulk, the naphthyl moiety facilitates a longer correlation length for helical order compared to an analogous minidendritic poly(phenylacetylene). These attributes suggest that the naphthyl moiety may be better suited for expressing helical chirality in monolayer domains. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4974–4987, 2007     

Synthesis and characterization of wholly aromatic poly(azomethine)s containing donor–acceptor triphenylamine moieties

N‐(4‐nitrophenyl)‐4′,4″‐bisformyl‐diphenylamine was synthesized from N‐(4‐nitrophenyl)‐diphenylamine by the Vilsmeier‐Haack reaction. Soluble aromatic poly(azomethine)s (PAMs) were prepared by the solution polycondensation of N‐(4‐nitrophenyl)‐4′,4″‐bisformyl‐diphenylamine and aromatic diamine in N‐methyl‐2‐pyrrolidone (NMP) at room temperature under reduced pressure. All the PAMs are highly soluble in various organic solvents, such as N,N‐dimethylacetamide (DMAc), chloroform (CHCl₃), and tetrahydrofuran (THF). Differential scanning calorimetry (DSC) indicated that these PAMs had glass‐transition temperatures (T_gs) in the range of 170–230 °C, and a 10% weight‐loss temperatures in excess of 490 °C with char yield at 800 °C in nitrogen higher than 60%. These PAMs in NMP solution showed UV‐Vis charge‐transfer (CT) absorption at 405–421 nm and photoluminescence peaks around 462–466 nm with fluorescence quantum efficiency (Φ_F) 0.10–0.99%. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of these PAMs can be determined from cyclic voltammograms as 4.86–5.43 and 3.31–3.34 eV, respectively. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4921–4932, 2007     

Synthesis and characterization of isoindigo‐based polymers using CH‐arylation polycondensation reactions for organic photovoltaics

A series of three new low bandgap donor–acceptor–donor–acceptor^/ (D–A–D–A^/) polymers have been successfully synthesized based on the combination of isoindigo as the electron‐deficient acceptor and 3,4‐ethylenedioxythiophene as the electron‐rich donor, followed by CH‐arylation with different acceptors (4,7‐dibromo[c][1,2,5]‐(oxa, thia, and/or selena)diazole ( 4a‐c )). These polymers were used as donor materials for photovoltaic applications. All of the polymers are highly stable and show good solubility in chlorinated solvents. The highest power conversion efficiency of 1.6% was achieved in the bulk heterojunction photovoltaic device that consisted of poly ((E)?6‐(7‐(benzo‐[c][1,2,5]‐thiadiazol‐4‐yl)?2,3‐dihydrothieno‐[3,4‐b][1,4]dioxin‐5‐yl)?6′‐(2,3‐dihydrothieno‐[3,4‐b][1,4]‐dioxin‐5‐yl)?1,1′‐bis‐(2‐octyldodecyl)‐[3,3′‐biindolinylidene]‐2,2′‐dione) as the donor and PC₆₁BM as the acceptor, with a short‐circuit current density (J_sc) of 8.10 mA/cm², an open circuit voltage (V_oc) of 0.56 V and a fill factor of 35%, which indicates that these polymers are promising donors for polymer solar cell applications. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2926–2933     

Electrochemical synthesis of PEDOT derivatives bearing imidazolium‐ionic liquid moieties

Novel poly(3,4‐ethylenedioxythiophene) (PEDOT) polymers bearing imidazolium‐ionic liquid moieties were synthesized by electrochemical polymerizations. For this purpose, new functional monomers were synthesized having an 3,4‐ethylenedioxythiophene (EDOT) unit and an imidazolium‐ionic liquid with different anions such as tetrafluoroborate (BF), bis(trifluoromethane)sulfonimide ((CF₃SO₂)₂N^?), and hexafluorophosphate (PF). Next, polymer films were obtained by electrochemical synthesis in dicholoromethane solutions. Obtained polymers were characterized, revealing the characteristics of PEDOT in terms of electrochemical and spectroelectrochemical properties, FTIR, ¹H NMR, and AFM microscopy. Interestingly, the hydrophobic character of electropolymerized films could be modified depending on the anion type. The hydrophobicity followed the trend PF > (CF₃SO₂)₂N^? > BF > pure PEDOT as determined by water contact angle measurements. Furthermore, the polymers could be dissolved in a range of polar organic solvents such as dimethylformamide, propylene carbonate, and dimethyl sulfoxide making these polymers interesting candidates for wet processing methods. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3010–3021, 2009