Synthesis and characterization of polyurethanes containing cholesterol and phosphatidylcholine analogous moieties

Several new polyurethanes containing cholesterol and phosphatidylcholine analogous moieties were synthesized by addition polymerization of 2-[bis(2-hydroxyethyl)methylammonio]ethyl 5-cholesten-3β-yl phosphate ( 2 ) with diisocyanates such as hexamethylene diisocyanate (HDI), 2,4-tolylene diisocyanate (TDI), 4,4′-methylenediphenyl diisocyanate (MDI) and m-xylylene diisocyanate (XDI), respectively. They were characterized by their IR and ¹H NMR spectral data and elemental analyses. Preliminary studies suggest that these polyurethanes show the viscosity behavior of common polyelectrolytes.     

Studies on syntheses and properties of novel polyamides containing phosphatidylcholine analogous moieties by interfacial polycondensation

Polyamides (4a-b and 5a-b) were synthesized from interfacial polycondensation of novel diamine containing phosphatidylcholine analogous moiety, hexamethylene diamine with adipoyl chloride, or sebacoyl chloride in the interface of water and carbon tetrachloride at room temperature. The characterizations of synthesized diamine and polyamides were carried out with FT-NMR, or IR spectral method, elemental analysis, and melting point measurements, respectively. These polyamides obtained are insoluble in any normal solvents. From the results of X-ray diffraction analysis and POM observation, it was revealed that the polyamide 4b was prepared with high molecular weight, while polyamide 4a obtained seemed to have low molecular weight. For copolymers 5a and 5b, X-ray reflections from only adipoyl or sebacoyl chloride parts were observed as in crystalline state. In addition, thermal properties were also studied by DSC and transmitted light intensity measurements. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 3065–3074, 1997     

Synthesis and properties of polyurethanes containing phosphatidylcholine analogues in the polymer backbone

New polyurethanes ( 4a, 4b ) and a segmented polyurethane ( 4c ) bearing phosphatidylcholine moieties in the main chain were synthesized. They are thermally stable up to 300°C and show the viscosity behaviour of common polyelectrolytes. Preliminary studies suggest that these polyurethanes are interesting new biomaterials.     

Synthesis,processing, and third-order nonlinear optical properties of benzobisthiazole polymers containing thiophene moieties

Benzobisthiazole polymers containing mono-, bi-, and terthiophene moieties were synthesized through polycondensation in polyphosphoric acid of 2,5-diamino-1,4-benzenedithiol dihydrochloride with thiophene-2,5-dicarboxylic acid, 2,2′-bithiophene-5,5′-dicarboxylic acid, and 2,2′:5′,2″-terthlophene-5,5″-dicarboxylic acid, or their corresponding diacid chlorides, respectively. Intrinsic viscosities of up to 8.1 dL/g (methanesulfonic acid, 30°C) were recorded. Polymer structures were verified by elemental analysis and spectroscopic comparison of the polymers with appropriate model compounds. Onset of breakdown under thermogravimetric analysis in air occurred in the 460–590°C range with the benzobisthiazole polymers containing a monothiophene linkage being the most stable. Films suitable for third-order optical susceptibility measurements could be prepared by extrusion techniques from the benzobisthiazole polymer containing a monothiophene linkage. Degenerate four wave mixing measurements on this film yielded a third order optical susceptibility χ⁽³⁾ of approximately 4.5 × 10^?10 esu. © 1993 John Wiley & Sons, Inc.     

Synthesis and properties of thermally cross-linkable main-chain azobenzene polymers containing diacetylene moieties

A series of main chain azobenzene polymers containing diacetylene moieties with different lengths of the spacer {-[CC-CH₂-O-C₆H₄-OCO-(CH₂)_m-O-C₆H₄-NN-C₆H₄-O-(CH₂)_m-OCO-C₆H₄-O-CH₂-CC]_n-, where m = 3, 6, 11} were synthesized by oxidative coupling polymerization. These polymers had molecular weights of 17,600-68,600 and polydispersity indices of 1.2-1.8 as determined by gel permeation chromatography using polystyrene as a standard. Their structures and properties were characterized and evaluated with NMR, FT-IR, X-ray diffraction (XRD), thermogravimetry (TG), differential scanning calorimetry (DSC) and nonlinear optical (NLO) analyses. All the polymers could be cross-linked at the elevated temperatures due to the polymerization reactions of the diacetylene groups in the polymer backbone, and the cross-linked polymers showed dramatically modified properties, such as thermal stability and solvent resistance. The third-order nonlinear susceptibilities of the cross-linked polymers were evaluated by means of the Z-scan technique and calculated to be 3.60 × 10⁻⁹, 2.73 × 10⁻⁹, 2.28 × 10⁻⁹ esu, respectively, whereas the un-cross-linked polymers showed no obvious NLO property.     

Synthesis and photochemical properties of solar energy storage-exchange polymers containing pendant norbornadiene moieties

New photoresponsive polymers 1–4 containing pendant norbornadiene (NBD) moieties with N,N-disubstituted amide groups were synthesized with 97, 98, 92, and 94% conversions by the substitution reaction of poly (p-chloromethyl) styrene] with potassium salts of 3piperidyloxo-2,5-NBD-2-carboxylic acid, 3-(NN-dipropylcarbamoyl) -2,5-NBD-2-carboxylic acid, 3-(N-methyl-N-phenylcarbamoyl)-2,5-NBD-2-carboxylic acid, and 3-(N,N-dipheylcarbmoyl)-2,5-NBD-2-carboxylic acid, respectively, using tetrabutylammonium bromide as a phase transfer catalyst for all. Polymers 1–4 with N,N-disubstituted amide groups on the NBD moieties were sensitized by adding appropriate photosensitizers such as Michler's ketone and 4- (N,N-dimethylamino) benzophenone in the film state, although the reactivities of the polymers without photosensitizer were lower than that of our previously reported polymer 5 containing pendant 3- (N-phenylcarbamoyl) -2,5-NBD-2-carboxylate moiety. It was also found that the photo-irradiated retaining polymers 1–4 containing the corresponding QC moieties can be stored about 80–86 kJ/mol of their thermal energy. © 1994 John Wiley & Sons, Inc.     

Synthesis and properties of novel polymers having S-methyldibenzothiophenium salt moieties

A polymer having dibenzothiophenium salt moieties [poly(sulfonium salt), 2 ] was prepared by the reaction of poly(2-vinyldibenzothiophene) ( 1 ) with CH₃I and AgBF₄ in CH₂ClCH₂Cl at room temperature for 24 h. The obtained polymer 2 was found to contain 71% of the methyldibenzothiophenium tetrafluoroborate unit. A monomer carrying the sulfonium salt moiety, i.e., 5-methyl-2-vinyldibenzothiophenium tetrafluoroborate ( 4 ), was independently prepared and subjected to radical polymerization to give a polymer ( 5 ) in 88% yield (methyldibenzothiophenium tetrafluoroborate unit: 79%). The thermal decompositions of 2 and 5 took place in two steps; the first step involved the formation of polymer 1 by demethylation. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1779–1784, 1998     

Synthesis and applications of polymers containing metallacyclopentadiene moieties in the main chain

Organometallic polymers containing metallacycles in the main chain were prepared by the reactions of diynes with low-valent organometallic complexes such as CpCo(PPh₃)₂, CP₂Ti(CH₂=CHC₂H₅), and (ⁱPrO)₂Ti(CH₂=CHCH₃). Their polymer reactions involving the conversion of the main chain structures gave rise to polymers containing functional groups in their main chain repeating units. Design and synthesis of organometallic polymers that potentially serve as novel functional materials are also described.     

Synthesis and characterization of polymers containing linear sugar moieties as side groups

The synthesis of a water-soluble monomer, namely 4-vinylphenyl-d-gluco(d-manno)hexitol (4) derived from d-gluconolactone, is here presented. The homopolymerization of the vinylsugar has been conducted in both aqueous and organic media using free-radical initiators. High-molar-mass water-soluble polymers are obtained. The copolymerization behavior of the vinylphenyl sugar monomer with a hydrophilic monomer such as acrylamide, as well as with a hydrophobic monomer such as styrene, has been investigated. Statistical- and block-type copolymers have thus been prepared. The structures of the polymers were confirmed by NMR and their thermal properties examined by DSC.     

Functional polymers with cyclic ether moieties. II. Synthesis and properties of network polymers with tetrahydrofuran moiety

A tetrahydrofuran (THF)‐containing network polymer was prepared by the radical suspension copolymerization of a styrene (St)‐type monomer with THF moiety, St, p‐chloromethylstyrene, and divinylbenzene in a biphasic medium consisting of water and monochlorobenzene in the presence of acacia gum as a suspension stabilizer. The diameters of the obtained polymer beads ranged from 100 to 200 μm. The obtained network polymer showed higher swelling abilities in various organic solvents than a similarly prepared network polymer without THF moiety, and it was stable under oxidative, reductive, and basic conditions. In its derivations to polystyrene‐based resins with thioether alcohol and hydroxyl moiety, remarkable accelerations of reactions were observed as a result of the introduction of THF moiety. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 800–806, 2001     

Synthesis and properties of wholly aromatic polymers bearing cardo fluorene moieties

Three series of aromatic polyamides, polyesters, and poly(1,3,4‐oxadiazole)s containing bulky fluorene structures were prepared from 9,9‐bis(4‐carboxyphenyl) fluorene. All of the polymers were readily soluble in many organic solvents and showed useful thermal stability associated with high glass‐transition temperatures in the range of 220–366 °C. These wholly aromatic polymer films were colorless, with high optical transparency, and exhibited UV‐vis absorption bands at 266–348 nm and photoluminescence maximum bands at 368–457 nm within the purple to green region in N,N‐dimethylacetamide (DMAc) solutions. The poly(amine‐amide) Ic exhibited excellent electrochromic contrast and coloration efficiency, changing color from the colorless neutral form to green and then to the dark blue oxidized forms with good stability of electrochromic characteristics. Almost all of these wholly aromatic polymer films were colorless and showed high optical transparency. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4352–4363, 2007     

Synthesis,UV-curing behavior and surface properties of fluorine-containing vinyl ether polymers

Five fluorine-containing vinyl ether monomers were prepared by the reaction between 2-vinyloxy ethanol, a fluorinated alcohol and hexafluorobenzene in the presence of sodium hydride in dimethylformamide. Two representative properties of these monomers, UV-curing behavior initiated by a cationic photo-initiator PAG 201 and surface free energy of coating films, were investigated. Photo-polymerization proceeded both rapidly and completely with a high double-bond conversion （〉 90%） and a fast curing rate （maximum curing time 〈 21 s） for three monomers. The surface energies of the monomers and the resulting polymer films were then investigated. The minimum surface free energy of the UV-cured homopolymer films reaches 7.1 mJ/m2. X-ray photoelectron spectroscopy data show that the low surthce tension is influenced by fluorine content in the soft segments and fluorinated chains＇ migration to the surface. The five monomers exhibit low viscosity, low surface energy, good thermal stability and good photo-polymerization properties, which make them great candidates for UV coating and photoresist applications.     

Synthesis and properties of conjugated polymers containing 3,9‐carbazolylene and silylenevinylene moieties in the main chain

Novel conjugated polymers containing 3,9‐carbazolylene and silylenevinylene moieties were synthesized by the hydrosilylation polymerization of 1,4‐bis(3‐ethynyl‐9‐carbazolyl)benzene ( 1 ) with various bis(hydrosilane)s or dihydrosilanes using a rhodium catalyst. Polymers with weight‐average molecular weights ranging from 5400 to 20,000 were obtained in 55–97% yields by the polyaddition with a rhodium catalyst in toluene at 25 °C for 24 h. All the polymers were soluble in CHCl₃ and THF, and had predominantly trans‐structures. The polymers exhibited λ_max at a longer wavelength region than 1 , and emitted fluorescence in 14–50% quantumn yields. The polymers were oxidized and reduced in the region of 0.4–1.6 V, and thermally stable up to 200 °C under air. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1815–1821, 2010     

Synthesis and stability of oligonucleotides containing acyclic achiral nucleoside analogues with two base moieties

[structure: see text] Nucleotide building blocks with two base moieties were synthesized and incorporated into oligonucleotides. One of the two bases is involved in base pairing within the double helix, while the other base is sticking out of the minor groove. This system may be used for presenting sequence information at the outside of the helix.     

Synthesis and properties of cyclolinear methylcyclotetrasiloxane polymers with vinyl groups

Atactic cyclolinear organosilicon polymers carrying vinyl groups in RSiO_1.5 or R₂SiO moieties or concurrently in two moieties of the polymer unit have been synthesized by the heterofunctional polycondensation of 2,6-dihydroxymethyl(vinyl)cyclotetrasiloxanes with 2,6-dichloromethyl(vinyl)cyclotetrasiloxanes. The structure of the polymers has been studied by ¹H and ²⁹Si NMR spectroscopy, IR measurements, and elemental analysis. According to DSC, X-ray diffraction, and polarization optical microscopy, the polymers are amorphous in the range from ?100 to +200°C; the interlayer spacing and the type of packing remain unchanged with an increase in the content of vinyl substituents in the repeating units of cyclolinear polymethylvinylsiloxanes.     

Synthesis of novel steroid analogues containing nitrile and disulfide moieties via palladium-catalyzed cross-coupling reactions

Grundmann's ketone (3) was used as a common building block for introduction of the C+D ring motif of steroids to prepare series of novel secosteroids containing nitrile or disulfide functionalities. Key steps in synthesis of these novel steroid analogues are palladium-catalyzed cross-coupling reactions. All target compounds were characterized by comprehensive analysis; in particular the stereochemical assignments of dinitriles 12a and 12b could be carried out in detail by NMR experiments. The pharmacological potential of all compounds was initially verified by a cytotoxicity test.