Linear polythioesters. XIV. Products of interfacial polycondensation isomeric di(mercaptomethyl) trimethylbenzenes with some aliphatic acid dichlorides

New polythioesters by interfacial polycondensation of 4,6-di(mercaptomethyl)-1,2,3,-trimethylbenzene, 3,5-di(mercaptomethyl)-1,2,4,-trimethylbenzene and 2,4-di(mercaptomethyl)-1,3,5-trimethylbenzene with adipoyl and sebacoyl chlorides were obtained. Process of polycondensation was carried out under the same condition as established earlier as an optimal for synthesis of polythioester from 2,5-di(mercaptomethyl)-1,4-dimethylbenzene and sebacoyl chloride. The conditions of polycondensation process were as follows: the organic phase benzene/hexane (1:1), ratio of aqueous to organic phase 1:1, the presence of 100% excess of NaOH as hydrogen chloride acceptor, temperature of reaction 15°C, little excess of acid dichloride with addition time 8.5 min. The structure of all polythioesters was determined by elementary analysis, infrared spectra, and X-ray analysis. Initial decomposition and initial intensive decomposition temperature were defined by the curves of thermogravimetric analysis. The molecular weights for these polymers were determined by gel chromatography.     

酸性树脂催化1,4-丁烯二醇制备2,5-二氢呋喃

提出1,4-丁烯二醇在酸性条件下脱水关环制备2,5-二氢呋喃的反应机理。实验对照了磺酸基树脂D61、D72以及膦酸基树脂LSC-500的催化性能,在5小时的反应过程中,它们的催化活性均逐渐下降,其中D61活性最强,平均每克催化剂1小时转化2.96克1,4-丁烯二醇,D61和D72的收率逐渐下降,LSC-500的收率最高而且比较稳定,保持在80%以上。     

Linear polythioesters. XII. Products of polycondensation some isomeric di(mercaptomethyl)trimethylbenzenes with isophthaloyl and terephthaloyl chlorides

New polythioesters by interfacial polycondensation of 4,6-di(mercaptomethyl)-1,2,3-trimethyl-benzene, 3,5-di(mercaptomethyl)-1,2,4-trimethylbenzene, and 2,4-di(mercaptomethyl)-1,3,5-trimethylbenzene with isophthaloyl and terephthaloyl chlorides were obtained. Polycondensation was carried out under the same conditions as established earlier as optimum for synthesis of polythioesters from 2,5-di(mercaptomethyl)-1,4-dimethylbenzene and isophthaloyl chloride. The conditions of polycondensation were as follows: the organic phase benzene/hexane, ratio of aqueous to organic phase 1:1, presence of 100% excess of NaOH as hydrogen chloride acceptor, temperature of reaction 15°C, little excess of acid dichloride with addition time of 8 min, catalyst benzyltriethylammonium chloride. Yield, reduced viscosity and molecular weight for reaction products have been found. The structure of all polythioesters was determined from elemental analysis, infrared (IR) spectra and x-ray analysis. Thermal properties were defined from the curves of thermogravimetric analysis. Some mechanical and electrical properties of the polythioesters obtained from di(mercaptomethyl)-trimethylbenzenes and isophthaloyl chloride were determined.     

The synthesis,absorption and fluorescence of polar diketo-pyrrolo-pyrroles

The effect of electron-donor (piperidino) and electron-acceptor (cyano) groups on the absorption maxima of some diketo-pyrrolo-pyrroles in DMSO solution was investigated both experimentally and theoretically. The syntheses of push–pull substituted 3-(4-piperidinophenyl)-6-(4-cyanophenyl)-2,5-dihydropyrrolo[3,4-c]pyrrol-1,4-dione are reported for the first time; 3,6-diphenyl-2,5-dihydropyrrolo[3,4-c]pyrrol-1,4-diones substituted with either one or two piperidino or cyano groups in the para-positions of the phenyl rings were also synthesized. Whilst both types of substituent produce a bathochromic and hyperchromic shifts with respect to the parent unsubstituted compound, the influence of the piperidino group is strongest. Symmetrically substituted derivatives show well-resolved vibronic structures, while the spectra of polar, unsymmetrical compounds were poorly resolved because of strong dipole–dipole interaction with the polar solvent. The fluorescence of all compounds was intense and a significant increase in the Stokes shift of polar derivatives was another consequence of dipole–dipole interactions with the solvent in the excited state.     

Absorption and fluorescence of soluble polar diketo-pyrrolo-pyrroles

Six soluble derivatives of 3,6-diphenyl-2,5-dihydro-pyrrolo[3,4-c]pyrrole-1,4-dione N-alkylated on pyrrolinone ring with polar substituents in para positions of pendant phenyl rings were synthesized; five of them are reported for the first time. Absorption and fluorescence spectra were studied in solvents of different polarity. The compounds show small solvatochromism of absorption and a moderate positive solvatochromism of fluorescence, especially when substituted by strong electron-donating piperidino substituent. A significant decrease of fluorescence quantum yields and its biexponential decay for dipolar derivatives in polar solvents was tentatively ascribed to the formation of twisted intramolecular charge transfer (TICT) excited state. All six compounds show fluorescence in polycrystalline solid-state with the maxima covering a range over 200 nm in visible and near infrared region.     

Absorption and fluorescence of soluble polar diketo-pyrrolo-pyrroles

Six soluble derivatives of 3,6-diphenyl-2,5-dihydro-pyrrolo[3,4-c]pyrrole-1,4-dione N-alkylated on pyrrolinone ring with polar substituents in para positions of pendant phenyl rings were synthesized; five of them are reported for the first time. Absorption and fluorescence spectra were studied in solvents of different polarity. The compounds show small solvatochromism of absorption and a moderate positive solvatochromism of fluorescence, especially when substituted by strong electron-donating piperidino substituent. A significant decrease of fluorescence quantum yields and its biexponential decay for dipolar derivatives in polar solvents was tentatively ascribed to the formation of twisted intramolecular charge transfer (TICT) excited state. All six compounds show fluorescence in polycrystalline solid-state with the maxima covering a range over 200 nm in visible and near infrared region.     

Synthesis and characterization of highly fluorescent phenylene vinylene containing perfluorocyclobutyl (PFCB) aromatic ether polymers

4-(Trifluorovinyloxy)benzaldehyde was treated under Wittig conditions with 4-dihexyloxy-2,5-xylenebis(triphenylphosphoniumbromide) to form 1,4-bis(2′-(4-trifluorovinyloxyphenyl)ethenyl)-2,5-dihexyloxybenzene, a novel phenylene vinylene-bistrifluorovinyl ether monomer. Cyclopolymerization afforded an insoluble, non-luminescent material likely due to cross-addition reactions between phenylene vinylene olefin and trifluorovinyl ether (TFVE). However, 1,2-bis(4-formylphenoxy)hexafluorocyclobutane was polymerized with 1,4-dihexyloxy-2,5-xylenebis(triphenylphosphoniumbromide) and 1-methoxy-4-(2-ethylhexyloxy)-2,5-xylenebis(triphenylphosphoniumbromide) under Wittig conditions to yield two novel poly(perfluorocyclobutyl-co-phenylene vinylene) polymers. The polymers are of moderate molecular weight (8600-8700 M_n), show excellent thermal stability (T_d = 390-405 °C), and are readily soluble in common organic solvents. The materials are highly fluorescent in both solution and thin film with solution quantum yields of 68 and 71%.     

Selective Hydrogenation of 2-Butyne-1,4-diol to 1,4-Butanediol Over Particulate Raney® Nickel Catalysts

The current study describes the results on the selective hydrogenation of the 2-butyne-1,4-diol to 1,4-butanediol over Raney^® nickel catalysts both in batch and in CSTR mode. The detailed kinetic analysis of the reaction in batch mode revealed the existence of three characteristic regions. In the first region, A, the starting 2-butyne-1,4-diol produces primarily cis-2-butene-1,4-diol. In the second region, B, the dominant species is cis-2-butene-1,4-diol, which is either hydrogenated to 1,4-butanediol or isomerizes to trans-2-butene-1,4-diol. In the third region, C, the accumulated 4-hydroxybutanal is slowly hydrogenated to 1,4-butanediol. When the same reaction was carried out in a CSTR mode, the only products detected initially are the 1,4-butanediol and n-butanol. The first by-product detected immediately after the end of the first stage is the linear hemiacetal between the 4-hydroxybutanal with 1,4-butanediol. This species has been used as convenient tracer for determining the length of the selective region of the catalyst performance.     

A convenient,one-step synthesis of 1,4-dithiin

A practical, high-yielding, one-step synthesis of 1,4-dithiin is described starting from commercially available 1,4-dithiane-2,5-diol.     

Synthesis and characterization of poly(2,5‐didecyl‐1,4‐phenylene vinylene), poly(2,5‐didecyloxy‐1,4‐phenylene vinylene), and their alternating copolymer

The preparation of dialkyl‐substituted poly(2,5‐didecyl‐1,4‐phenylene vinylene) ( PDDPV ) by the Horner‐Emmons polycondensation is described. Its performance in an organic light‐emitting diode (OLED) device architecture is compared with devices prepared from the analogous dialkoxy‐substituted poly(2,5‐didecyloxy‐1,4‐phenylene vinylene) ( PDOPV ) and the corresponding alkyl‐alkoxy‐substituted alternating copolymer. Additionally, the structure, stability, electrochemical, and optical properties of the PPVs were characterized by gel permeation chromatography, thermogravimetric analysis, NMR spectroscopy, cyclic voltammetry, UV‐Visible spectroscopy, and fluorescence spectroscopy. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41162.     

Synthesis and characterization of some polyurethane ionomers

Polyurethane ionomers based on either poly(propylene glycol), PPG, or poly(ethylene glycol), PEO, and di- (4-isocyanatophenyl) methane, MDI, butane-1,4-diol and cis-2-butene-1,4-diol have been synthesized and characterized. Attempts to convert the unsaturated polyurethanes directly to ionomers by reaction with N-chlorosulphonyl isocyanate, CSI, followed by hydrolysis, failed due to the more favoured reaction of CSI with the labile hydrogen on the urethane linkage. Therefore, the cis-2-butene-1,4-diol was first converted to the dibenzoate which was then treated with CSI to form the β-lactam derivatives. Subsequent hydrolysis of these derivatives with tetra-n-butyl ammonium hydroxide solution produced ionic derivatives whilst at the same time regenerating the terminal -OH groups. These ionic diol intermediates were then used for synthesizing the polyurethane ionomers.     

Graft copolymerization of unsaturated segmented polyurethanes with 2-hydroxyethyl methacrylate

Relatively high molecular weight unsaturated segmented polyurethane synthesized from poly(ethylene glycol), methylene bis(4-phenyl isocyanate), cis-2-butene-1,4-diol, and butane-1,4-diol was modified by graft copolymerization reaction. 2-Hydroxyethyl methacrylate (HEMA) monomer was grafted onto the unsaturated segmented polyurethane using 2,2′-azobisisobutyronitrile (AIBN) as initiator in N,N-dimethylformamide (DMF) as solvent. The graft copolymers were isolated by selective solvent extraction in a Soxhlet apparatus. The effect of reaction time, initiator concentration, reaction temperature, and monomer concentration on the graft yields has been examined. The graft yields were enhanced by increased monomer concentration and reaction temperature.     

Poly(p-phenylene) graft copolymers with polytetrahydrofuran/polystyrene side chains

1,4-Dibromo-2,5-bis(bromomethyl)benzene was used as a bifunctional initiator in cationic ring opening polymerization (CROP) of tetrahydrofuran. The resulting macromonomer, with a central 2,5-dibromobenzene ring, was reacted in combination with 2,5-dihexylbenzene-1,4-diboronic acid by a Suzuki coupling, in the presence of Pd(PPh₃)₄ as catalyst, leading to a poly(p-phenylene) (PPP) with alternating polytetrahydrofuran (PTHF) and hexyl side chains. A polystyrene (PSt) based macromonomer with a central benzene ring bearing cyclic boronic acid propanediol diester groups, synthesized by atom transfer radical polymerization (ATRP), was also used as partner for PTHF in the cross-coupling reaction. A PPP with alternating PSt and PTHF side chains was obtained. PTHF macromonomer was also homopolymerized by a Yamamoto reaction. The resulting PPPs have high solubility in common organic solvents at room temperature. The new polymers were characterized by GPC, ¹H NMR, ¹³C NMR, IR and UV analysis. Thermal behavior of the precursor PTHF macromonomer and the final polyphenylenes were investigated by TGA and DSC analyses and compared.     

One-pot synthesis of novel ladder type condensation polymers via condensation reactions of dihydroxyaromatic compounds and 2,5-dimethoxytetrahydrofuran

The one-pot polycondensation of dihydroxyaromatic compounds such as hydroquinone, 2,2-di(4-hydroxy phenyl) propane (Bisphenol A), 4,4′-dihydroxybiphenyl, dihydroxynaphthalenes (1,5- and 2,6-) with 2,5-dimethoxytetrahydrofuran as a reactive protected 1,4-dicarbonyl compound using trifluoroacetic acid as both solvent and condensing agent leads to condensation polymers having linear and ladder structure with high thermal stability. Optimal conditions for polycondensation were obtained via study of the model compounds. All polymers were obtained in high yields and with varying molecular weights (η = 0.16–0.31 dl/g). The structure of the polymers were characterized by NMR, FTIR spectroscopies and TG.     

Selective Synthesis of 1,4‐Dialkylbenzenes from Terephthalic Acid

Terephthalic acid reacts with alkyl halides under Birch conditions to substituted 1,4‐cyclohexadienes in high yields and good stereoselectivities. Electrophiles containing ester or nitrile groups undergo a surprising fragmentation under the reaction conditions. Subsequent treatment with chlorosulfonic acid proceeds by an interesting tandem decarbonylation/decarboxylation, affording 1,4‐dialkylbenzenes in excellent regioselectivity. Thus our new method is superior to classical Friedel–Crafts alkylations.     

The synthesis of quinodimethanes in the benzodifuranone and benzodipyrrolidone series

The condensation of hydroquinone and 2,5-substituted hydroquinones with mandelic acids, or of 1,4-benzoquinone and 2,5-substituted 1,4-benzoquinones with mandelic acids or arylacetic acids gives 3,7-diaryl-2,6-dioxo-2,6-dihydrobenzo[1,2-b:4,5-b′]difuran derivatives. Analogous benzodipyrrolidones have been obtained from 1,4-phenylenediamine and N,N′-dimethyl-1,4-phenylenediamine. Both series are novel chromogens and have application as dyestuffs. The red compound obtained from 1,4-benzoquinone and cyanoacetic acid and reported to be a lin-pentacenetriquinone has been shown to be 3,7-bis(4-hydroxyphenyl)2,6-dioxo-2,6-dihydrobenzo[1,2-b:4,5-b′]difuran.     

2-丁炔-1，4-二醇双对甲苯磺酸酯的合成工艺研究

以25％氢氧化钠为缚酸剂、以2-丁炔-1,4-二醇和对甲苯磺酰氟为原料,经磺酯化反应合成了2-丁炔-1,4-二醇双对甲苯磺酸酯。在n（对甲苯磺酰氯）：”（Na0H）;n（2-丁炔-1,4-二醇）为2．6：2．4：1、反应温度为0℃、反应时间为6h的最佳反应条件下,2-丁炔-1,4-二醇双对甲苯磺酸酯的收率迭94．1％。通过元素分析、IR以及1 HNMR对产物结构进行了表征。     

2,5-二氧-1,4-环己烷二甲酸二甲酯合成工艺研究

采用过量的丁二酸二甲酯作为反应溶剂 ,以甲醇钠与丁二酸二甲酯合成 2 ,5 二氧 1,4 环己烷二甲酸二甲酯的合成工艺 ,研究了原料配比、反应温度及反应时间对产品收率的影响。在n(丁二酸二甲酯 )∶n(甲醇钠 ) =4 3∶1 0、反应温度 10 0℃及回流反应时间 2 5～ 30min的最佳合成工艺条件下 ,得到质量分数为 97 5 %的 2 ,5 二氧 1,4 环己烷二甲酸二甲酯 ,以甲醇钠计其收率为 88 1%。     

Verwendung neuer halogenpolyole zur PUR-hartschaumerzeugung mit verminderter brennbarkeit

The usefulness of 3,5-dibromohexane-1,4-diol, 3,5-dichloroheptane-1,4-diol, 3,5-dibromoheptane-1,4-diol, 2-(4,5-dichlorophentyl)propane-1,3-diol and 2-(4,5-dibromopentyl)propane-1,3-diol for the synthesis of rigid polyurethane foams with reduced combustibility was investigated. In addition possibility of utilization of hexane-1,4-diol, heptane-1,4-diol, 2-(pent-4-enyl)propane-1,3-diol and 6-hydroxymethylheptane-1,2,7-triol for the manufacture of foamed polyurethanes is examined too.     

Synthesis and Characterization of Sporopollenin-Supported Schiff Bases and Ruthenium(III) Sorption Studies

Two Schiff base derivatives, (2-pycolylimino)benzen-1,4-diol and (2-pyridylimino)benzen-1,4-diol) were immobilized onto sporopollenin (Lycopodium clavatum) surfaces. The compounds were fully characterized by an infrared spectroscopy, elemental analysis, scanning electron microscopy, and X-ray diffraction techniques. The sorption capacities of the immobilized surfaces toward Ru(III) ions were investigated by batch sorption experiments. For the sorption experiment, the Ru(III) concentration, initial pH, and the temperature effects were studied. The isotherm data of Ru(III) ions were correlated reasonably well as a Freundlich sorption isotherm. The thermodynamic studies showed that the Ru(III) sorption onto immobilized sporopollenin derivatives is a non-spontaneous, endothermic and physical reaction.