Friedel-crafts copolymerization of thiophene and p-di(chloromethyl)benzene. I. Products,kinetics, and mechanism of the early stages of the reaction

The rate of polymerization of thiophene, at concentrations of catalyst (SnCl₄), and thiophene of the same order as was subsequently used in studying the reaction between thiophene and di(chloromethyl)benzene, is of the order of 10^-2%/hr at 30°C. There is no significant self-condensation of DCMB under the same conditions. Since the reaction between thiophene and DCMB is complete at 30°C in minutes rather than hours, it is assumed that self-condensation of thiophene or DCMB during the reaction between them will be negligible and should not influence the course of the reaction or the structure of the resulting polymer. Reaction at 30°C is much too fast for convenient study. A temperature of 0°C is more appropriate and was used in subsequent kinetic work. The first two products of the condensation of p-di(chloromethyl)benzene (DCMB) with thiophene have been identified by a combination of mass, infrared, and nuclear magnetic resonance spectroscopy as thenylchloromethylbenzene (TCMB) and dithenylbenzene (DTB). DCMB, TCMB, and DTB have been estimated quantitatively during the course of the reaction by gas-liquid chromatography (GLC), and it has been established that the rates of each of the two reaction steps is first-order with respect to the chloro compound (DCMB and TCMB respectively), thiophene, and SnCl₄. Rate constants for these two consecutive reactions were calculated to be k₁ = 2.79 × 10^-4l.²/mole²-sec, k₂ = 6.37 × 10^-3l.²/mole²-sec; the corresponding energies of activation are E₁ = 7.93 kcal/mole, E₂ = 7°67 kcal/mole. These rate constants are appreciably higher than values previously obtained for the corresponding DCMB–benzene reactions.     

Synthesis and characterization of new copolymers of thiophene and vinylene: Poly(thienylenevinylene)s and poly(terthienylenevinylene)s with thioether side chains

Poly[3,4-bis(3-methylbutylthio)thienylenevinylene], poly[3,4-bis-(S)-(2-methylbutylthio)thienylenevinylene], poly[3′,4′-bis(3-methylbutylthio)-2,2′:5′,2″-terthienylene-5,5″-vinylene], and poly{3′,4′-bis-(S)-[2-methylbutylthio]-2,2′:5′,2″-terthienylene-5,5″-vinylene} have been synthesized. The synthesis starts from the thiophene monomers and trimers, which are formylated to give the corresponding dialdehydes. The dialdehydes are reductively polymerized using a McMurry coupling. The polymers are characterized by GPC, optical spectroscopy (FT-IR, UV-vis, circular dichroism spectroscopy and photoluminescence) and by proton and carbon NMR spectroscopy. The polymers are soluble in common organic solvents, such as THF, chloroform, toluene, benzene and 1,2-dichlorobenzene. The solvatochromism and thermochromism of the polymers in solution are investigated, while the optical activity of the polymers is used to investigate the supramolecular aggregation. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 4629–4639, 1999     

离子液体催化剂用于煤焦化苯深度脱硫制无硫苯

从扩大有机合成用苯的需求出发,采用研制的离子液体催化剂考察了煤焦化苯深度脱硫制无硫苯的过程。结果表明：N-甲基咪唑硫酸氢盐[Hmim][HSO₄]离子液体催化剂脱噻吩效果与其酸函数值有关。本文采用Hammett指示剂测定离子液体的酸函数H₀,并得出：在-4至-12的范围,离子液体催化剂可以使煤焦化苯噻吩脱至0. 5mg/L以下。与固体酸催化机理相似,酸量和酸强度一定的离子液体催化剂通过Friedel-Crafts反应形成烷基噻吩等,与苯的物性拉开距离,对苯的分离精制是必不可少的,但是过多、过强的[Hmim][HSO₄]酸值也更有利于苯-噻吩-烯烃共聚合等副反应的发生,从而影响离子液体催化剂重复使用的寿命。本研究利用煤焦化苯脱硫反应形成的噻吩衍生物作为提供电荷流通的聚合物,将反复使用后性能不佳的离子液体成分等作为“受电子型”和“给电子型”的掺杂剂,进行导电（抗静电）材料的制备。结果显示：对煤焦化苯脱硫形成的噻吩衍生物等可以用于掺杂导电材料的试制。     

Synthesis and characterization of copolymers based on cyclopenta[c]thiophene and bithiazole and their transistor properties

Two new copolymers, P1 and P2 , containing 5,5‐bis(dodecyloxymethyl)?5,6‐dihydro‐4H‐cyclopenta[c]thiophene (DCPT) or DCPT‐based thiophene trimer (as donor) and 4,4′‐dibutyl‐2,2′‐bithiazole (BTz, as weak acceptor) have been synthesized. To reduce the steric hindrance and enhance the conjugation, the thiophene spacers have been incorporated between DCPT and BTz in P2 , which play an important role in maintaining the side chain ordering and π‐stacking interactions. Both the polymers showed π‐stacking with similar distances (～0.37 nm) but with larger extent in P2 . Combination of DCPT with BTz has resulted in low lying HOMO levels for the resulting polymers with significant improvement in oxidative stability. P1 and P2 showed p‐type mobility of 0.03 and 0.052 cm² V^?1 s^?1 with current on/off ratio (I_on/I_off) in the order of 10⁴ and 10³, respectively. These differences in characteristics may be attributed to the variation in donor (D)–acceptor (A) property, supramolecular ordering, extent of π‐stacking, and film microstructure. The polymers were further characterized by GPC, TGA, DSC, PXRD, cyclic voltammetry, and atomic force microscopy. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 4481–4488     

The insertion and extrusion of heterosulfur bridges. IX: Sulfur bridging in 2-phenylnaphthalene

Sulfur bridging of 2-phenylnaphlhalene ( 3 ) to form benzo[b ]naphtho[2,1-d]thiophene ( 5 ) (main product) and the isomeric benzo[b]naphtho[2,3-d]thiophene ( 4 ) is effected by means of hydrogen sulfide, benzene (solvent), and a sulfided cobaltous oxide-molybdic oxide-alumina (CMA-1) catalyst at 450–630° in a flow system (maximum yield 33% at 500°). The low yield is ascribed to decompositions of both 4 and 5 under reaction conditions.     

Crystal structure and reactivity of 2-chloro-3,5-dinitrothiophene and of 2-phenylsulphonyl-3,5-dinitrothiophene with nucleophiles

The geometry obtained by a crystal structure determination of the title compounds, as compared with that of the analogous benzene derivatives, along with results of ab initio calculations, is used to interpret the different S_NAr reactivities in some thiophene and benzene compounds. The smaller rotation of the nitro groups with respect to the aromatic rings observed in thiophene derivatives should be considered a relevant factor in the higher reactivity in the thiophene series.     

Friedel-Crafts crosslinking of polystyrene

Polystyrene may be crosslinked by p-dichloromethylbenzene (DCMB) in 1,2-dichloroethane solution with SnCl₄ as catalyst. Combined intra- and intermolecular crosslinking can be measured by evolution of hydrogen chloride and by an ultraviolet spectral method, and the results for the two methods are in excellent agreement. Intermolecular crosslinking may be calculated separately from number-average molecular weight measurements, so that the extent of intramolecular crosslinking may be deduced by difference. Rate equations for the overall, intermolecular, and intramolecular reactions have been obtained as follows: The anomalous behavior with respect to polystyrene concentration may be due to inhibition of the intramolecular reaction because of increasing interpenetration of polystyrene molecules as the concentration of polystyrene is increased. The rate constant for the intermolecular reaction, which shows “normal” kinetic behavior has been compared with values for the reaction of DCMB with the model compounds benzene, toluene, diphenylmethane, and benzyl chloride. The very much smaller value for polystyrene compared with the models has been accounted for in terms of adverse steric effects when the reaction is occurring in the polymer chain environment.     

原位傅里叶变换红外光谱研究Y型分子筛表面酸性对吸附有机分子的影响

采用吡啶原位吸附傅里叶变换红外(Py-FTIR)光谱对液相离子交换(LPIE)和固相离子交换(SSIE)法制备的CeY分子筛以及HY和NaY的酸性进行了测定. 在原位条件下采用单探针分子噻吩、环己烯和苯对其在分子筛上的吸附过程进行了研究; 以噻吩和环己烯、噻吩和苯组成的双探针分子对吸附过程中存在的竞争吸附、催化反应以及吸附机理进行了系统研究. 结果表明, HY和L-CeY 分子筛表面强Brönsted (B)酸性位可导致吸附在其表面的噻吩发生低聚反应以及吸附的环己烯产生二聚环己烯碳正离子. 低聚的噻吩和吸附的环己烯在分子筛上发生强的化学吸附, 进一步抑制和阻碍噻吩硫化物与分子筛吸附活性中心发生作用, 从而降低了吸附剂的选择性以及吸附硫化物的能力. 吸附剂表面Lewis (L)酸中心是吸附的主要活性中心, 大量弱的L 酸, 有利于噻吩吸附. 并且, S-CeY分子筛表面弱的L酸对吸附噻吩具有一定的选择性, 它受到环己烯的影响较小, NaY吸附剂对噻吩、环己烯和苯选择性较差, 它只与吸附质作用的先后有关.     

Condensed Isoquinolines. 12. Synthesis of Novel Heterocyclic Systems Containing a Partially Hydrogenated Spiro[isoquinoline-4,4'-(2H)-pyran] Fragment

By condensation of 4-(2-bromomethyl)-3,4,5,6-tetrahydro-2H-pyran-4-carbonitrile with anthranilic acid, its derivatives substituted in the benzene ring (esters, nitrile), and with esters of 2-aminothiophene-3-carboxylic acids and 3-amino-5-bromobenzofuran-2-carboxylic acid there have been synthesized novel derivatives which include spiro-linked tetrahydropyran and 5,10-dihydro-3H-pyrimido[1,2-b]isoquinoline fragments. The pyrimidine ring of the latter was annelated by a substituted benzene, thiophene, or 5-bromobenzofuran ring.     

Synthesis and characterization of new sulfone‐derivatized phenylenevinylene‐based conjugated copolymers with evolving energy levels and gaps

A new series of stable, processable, and chain end functionalizable sulfone‐derivatized phenylenevinylene‐based conjugated polymers (SFPVs) containing different donor type comonomers have been synthesized and characterized. The polymer main chains are consisted of a sulfone‐phenylene electron accepting unit coupled with an electron donating unit which is derived from one of the dialdehyde comonomers based on benzene, thiophene, and pyrrole (with or without alkoxy side chains). The optical energy gaps (E_g) of the new polymers (in solvent) are in a range of 1.9–2.3 eV, with the lowest energy gap obtained from the polymer containing pyrrole as the donor unit. By using a combination of strong donor unit (such as pyrrole) and a relatively weak but stable acceptor unit (sulfone‐substituted benzene), E_g of the conjugated polymers can be tailored to below 2 eV, while the vinylene bonds on the polymer main chain are still chemically stable to survive strong basic conditions as compared with the S,S‐dioxo‐thiophene‐based PTV polymers developed earlier for potential supra‐molecular block copolymer systems. The lowest energy gap P(Pyrrole‐SFPV) exhibited 10 times better photoelectric power conversion efficiency than P(TV‐SFPV). © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Synthesis of Thiophene-fused Helicenes

The synthesis of three penta- and three hexahelicenes containing two terminal thiophene units is described. The syntheses of pentahelicenes consist of 1,4-bisalkynylation of a benzene precursor and double Suzuki coupling in 2,3-position to introduce thiophene units. The ortho,ortho’ fusion yielding the final products was achieved with Fürstner's protocol using platinum(II) chloride or JohnPhos-complexed gold(I) as catalysts. A similar approach to hexahelicenes started with a naphthalene derivative, where 2,7-bisalkynylation and subsequent double Suzuki coupling with thiophene-2-boronic acid at 1,8-position furnished precursors, in which ortho,ortho’ fusion to the respective hexahelicenes was achieved with platinum(II) chloride or, favourably, with indium(III) chloride. UV/Vis spectra and cyclic voltammograms were recorded for all helicenes and HOMO/LUMO gaps were calculated with DFT methods.     

Cycloaddition approach to the curing of polyimides via precursor containing thiophene‐S,S‐dioxide

A new method for linear polymerization of maleimides via the Diels–Alder reaction has been developed. This method involves use of a new cross‐linking agent, benzene‐3,4‐dimethylenesuccinimide, which can be generated in situ from its thiophene precursor, benzene‐2,5‐dihydrothiophene‐3,4‐dicarboximide‐S,S‐dioxide. This new cross‐linking agent is reasonably reactive, readily prepared, and stable at room temperature. A controlled molecular weight oligomer has been synthesized and applied to the polymerization to yield a highly thermal stable polyimide. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:648–652, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20249     

Liquid crystalline compounds in the thiophene series. VIII. Synthesis and characterization of liquid crystalline vinylenes with thiophene moieties and carbaldehyde groups

New thermotropic liquid crystal compounds, with one and two mesogenic groups, have been synthesized and characterized. The structural elements of the compounds consist of thiophene ring systems, vinylene units and, for some compounds, carbaldehyde groups. Mesogenic groups involving three thiophene ring systems are normally not liquid crystalline. Only in the case of E,E-5-[5-(5-butyl-2-thienylvinyl)-2-thienylvinyl]-2-thiophenecarbaldehyde could a monotropic nematic phase be easily observed. By replacing thiophene ring systems in the core with a benzene ring system, or by attaching one carbaldehyde group at the moieties, or by doubling the mesogenic groups via an alkylene spacer, the temperature ranges of the mesophases of the compounds with thiophene ring systems can be enlarged or liquid crystal phases induced. The small values for δS_NI, which have been observed for the low molecular weight compounds, indicate a very low order in the nematic phases.     

Identification of intact oxidation products of glycerophospholipids in vitro and in vivo using negative ion electrospray iontrap mass spectrometry

Free radical‐induced oxidation products of polyunsaturated fatty acids esterified to phospholipids have been implicated in a number of human diseases including atherosclerosis and neurodegenerative diseases. Some of these phospholipid oxidation products have potent biological activities and likely contribute to human pathophysiological conditions. Oxidation products have also been used as markers of oxidative stress in vivo. Identification and quantification of phospholipid oxidation products are often performed by analyzing the oxidized free fatty acid moieties after hydrolysis from the phospholipids head groups by gas chromatography–mass spectrometry (GC–MS) or liquid chromatography–mass spectrometry (LC–MS). We now describe the definitive identification of intact oxidized products of glycerophospholipids including glycerophosphatidylcholine (GPC), glycerophosphatidylethanolamine (GPE), and glycerophosphatidylserine (GPS) in vitro and in vivo using iontrap MS. For these analyses, the negative ions of the oxidation products of phospholipids are fragmented to MSⁿ and unequivocal structural characterization is obtained based on collision‐induced dissociation (CID) of the sn‐2 carboxylate ion. This technique overcomes the need to hydrolyze fatty acids from phospholipids in the analysis. The method has been used to identify a number of oxidation products of glycerophospholipids including hydroxyeicosatetraenoates (HETEs) and isoprostanes (IsoPs) esterified to different classes of glycerophospholipids in vitro and in vivo. These studies thus provide a new approach to identify the intact oxidation products of glycerolphospholipids. Copyright © 2009 John Wiley & Sons, Ltd.     

A new solvent system for gel-permeation chromatography of poly(ethylene terephthalate)

A new solvent system comprising a mixture of nitrobenzene and tetrachloroethane has been developed for determining the molecular size distribution of poly(ethylene terephthalate) (PET) by gel-permeation chromatography (GPC). Unlike hot m-cresol, which until now has been the standard GPC solvent for PET, the nitrobenzene–tetrachloroethane mixture can be used at room temperature and thus minimizes polymer degradation and distribution equilibration. Results with this new system reveal reproducibly discernible differences between PET samples prepared by melt and solid-state polymerization, differences not previously noted in GPC reports based on the use of m-cresol.     

Tuning the Spectroscopic,Electrochemical, and Photovoltaic Properties of Triaryl Amine Based Sensitizers through Ring‐Fused Thiophene Bridges

The ring‐fused thiophene derivatives benzo[c]thiophene and its precursor bicyclo[2.2.2]octadiene (BCOD) have been introduced as π‐conjugated spacers for organic push–pull sensitizers with dihexyloxy‐substituted triphenylamine as donor and cyanoacrylic acid as acceptor ( OL1 , OL2 , OL3 , OL4 , OL5 , OL6 ). The effects of the fused ring on the spectroscopic and electrochemical properties of these sensitizers and their photovoltaic performance in dye‐sensitized solar cells have been evaluated. Introduction of a binary benzo[c]thiophene and ethylenedioxy thiophene as π bridge caused a significant red shift of the characteristic intramolecular charge‐transfer band to 642 nm. It is found that the sensitizer OL3 , which contains one benzo[c]thiophene unit as π linker, gives the highest overall conversion efficiency of 5.03 % among all these dyes.     

Peculiarities of polyacrylamide analysis by aqueous GPC

Various commercially available stationary phases of gel permeation chromatography (GPC) were tested to determine their effectiveness in aqueous exclusion chromatography. It was found that controlled pore glass (GPG) is the most suitable material for the separation of polyacrylamides and poly(acry1amide-co-sodium acrylate), dextrans, and poly(sodium styrene–sulfonates) in 0.1M aqueous Na₂S0₄ solutions of ionic strength 0.3. A calibration curve was established by using broad molecular weight distribution polyacrylamide standards in a trial and error procedure. To avoid artificial oscillations on the evaluated distribution curves a cubic B-spline representation of the calibration curve was used instead of the conventional polynomials. By applying this system the solution instability of polyacrylamides was observed by GPC and is discussed because of its general importance to the applicability of indirect molecular weight determination methods for polyacrylamides. The effectiveness of aqueous GPC was demonstrated in an evaluation of thermal degradation measurements of polyacrylamides. Finally, the feasibility of universal calibration of aqueous GPC by means of poly(sodium styrene–sulfonates) was investigated. It is apparent that in spite of some problems concerning adsorption of the polymer universal calibration is a successful tool for calibrating aqueous GPC.     

The insertion and extrusion of heterosulfur bridges. XV. S-bridging of 2,2′-binaphthyl and 1-(2-naphthyl)cyclohexene. Studies on hydrodehalogenation during the reaction

Regioselectivity occurs in the sulfur-bridging reactions of 2,2′-binaphthyl (1) and 1-(2-naphthyl)cyclohexene (7) by means of hydrogen sulfide and a chromia-alumina-magnesia catalyst (designated I) in a flow apparatus at 550°. Thus, 1 gives a higher yield (6.1%) of dinaphtho[1,2–6:2′,l'-d]thiophene from 1,1′-bridging than of dinaphtho[1,2-b:2′,3′-d]thiophene (3.4%) from l,3′-bridging. No product expected from 3,3′-bridging was identified. Substrate 7 undergoes both dehydrogenation and bridging to yield 2-phenylnaphthalene (8%), benzo[b]naphtho[2,1-d]thiophene (9%) from alpha bridging, and benzo[b]naphtho[2,3-d]thiophene (3%) from beta bridging into the naphthalene ring. Exploratory studies showed that either sulfided catalyst I or a sulfided molybdenum( VI ) oxide-alumina-cobalt( II ) oxide catalyst ( II ) effects hydrodehalogenation of various monohalo- and polyhaloarenes (where halo, X, is chloro or bromo) at 450–550°. In the biphenyl, phenanthrene, naphthalene, and pyrene systems, halogen was lost either under sulfur-bridging conditions or under hydrogenolysis conditions, i.e. with methanol as a reactant. For every substrate the parent arene was isolated or identified as a reaction product. In selected experiments, acid HX was also identified in the effluent. Use of hydrogen sulfide as a reactant led to formation of dibenzothiophene and phenanthro[4,5-bcd]thiophene as main products in the biphenyl and phenanthrene systems, respectively; while use of methanol as a reactant gave small amounts of methyl bromide (for X = Br) and methylarenes.     

Crystallinity and the effect of ionizing radiation in polyethylene. III. An experiment on the irradiation-induced crosslinking in n-hexatriacontane

Samples of n-hexatriacontane irradiated in the crystalline and molten states were compared as regards the GPC chromatograms of the partially crosslinked products. From differences in the elution volumes it could be inferred that there is a greater trend for random linking along the chain in the sample irradiated in the melt as opposed to preference for end-type linking in the samples irradiated as crystals. In the course of this work the applicability of the GPC technique for detecting short (methyl) branches and for distinguishing between the position of these branches along the chain has also become apparent.     

The insertion and extrusion of heterosulfur bridges. XII. Selectivity and side reactions in the bridging process

1-Phenylnaphthalene undergoes sulfur bridging at 500° in the presence of hydrogen sulfide and a heterogeneous catalyst to produce benzo[b]naphtho[1,2-d]thiophene (13%). 3-Methylphenanthrene and 9-formylphenanthrene diethyl acetal ( 7b ) give sulfur bridging to produce phenanthro[4,5-bcd]thiophene, i.e. with loss of the ring substituent. Additionally, 7b hydrogenolyzes to 9-methylphenanthrene. With decadeuteriobiphenyl as a substrate, the dibenzothiophene formed, as well as the biphenyl recovered, is largely devoid of deuterium label. Confirmation that benzene and toluene react under sulfur-bridging conditions is presented.