Crystal-to-Crystal Synthesis of Helically Ordered Polymers of Trehalose by Topochemical Polymerization

The synthesis of crystalline helical polymers of trehalose via topochemical azide–alkyne cycloaddition (TAAC) of a trehalose-based monomer is presented. An unsymmetrical trehalose derivative having azide and alkyne crystallizes in two different forms having almost similar packing. Upon heating, both the crystals undergo TAAC reaction to form crystalline polymers. Powder X-ray diffraction (PXRD) studies revealed that the monomers in both the crystals polymerize in a crystal-to-crystal fashion; circular dichroism (CD) studies of the product crystals revealed that the formed polymer is helically ordered. This solvent-free, catalyst-free polymerization method that eliminates the tedious purification of the polymeric product exemplifies the advantage of topochemical polymerization reaction over traditional solution-phase polymerization.     

Preparation and polymerization of N-(1,1-dimethyl-3-hydroxybutyl) acrylamide and N-(1,1-dimethyl-3-hydroxybutyl)methacrylamide

The syntheses of N-(1,1-dimethyl-3-hydroxybutyl)acrylamide and the corresponding methacrylamide by reduction of the oxobutyl acrylamides are described. These monomers are colorless liquids which are soluble in water and many organic solvents. They polymerize readily to form homopolymers and copolymers with other vinyl monomers. The preparation of polymers containing these repeating units by reduction of polymers of diacetone acrylamide and diacetone methacrylamide is also described.     

Topochemical Polymerization of 1,3‐Diene Monomers and Features of Polymer Crystals as Organic Intercalation Materials

From the viewpoint of controlled polymer synthesis, topochemical polymerization based on crystal engineering is very useful for controlling not only the primary chain structures but also the higher‐order structures of the crystalline polymers. We found a new type of topochemical polymerization of muconic and sorbic acid derivatives to give stereoregular and high‐molecular weight polymers under photo‐, X‐ray, and γ‐ray irradiation of the monomer crystals. In this article, we describe detailed features and the mechanism of the topochemical polymerization of diethyl‐(Z,Z)‐muconate as well as of various alkylammonium derivatives of muconic and sorbic acids, which are 1,3‐diene mono‐ and dicarboxylic acid derivatives, to control the stereochemical structures of the polymers. The polymerization reactivity of these monomers in the crystalline state and the stereochemical structure of the polymers produced are discussed based on the concept of crystal engineering, which is a useful method to design and control the reactivity, structure, and properties of organic solids. The reactivity of the topochemical polymerization is determined by the monomer crystal structure, i.e. the monomer molecular arrangement in the crystals. Polymer crystals derived from topochemical polymerization have a high potential as new organic crystalline materials for various applications. Organic intercalation using the polymer crystals prepared from alkylammonium muconates and sorbates is also described.     

Self-assembly of various guest substrates in natural cellulose substances to functional nanostructured materials

Biological organisms are produced from self-assembly of highly ordered functional units and are inherently complex and hierarchical, possessing macro-to-nanoscale features. It is a facile, low-cost and environmentally benign short-cut to artificial functional materials with unique multilevel structures and morphologies employing biological substances as platform for the self-assembly of various guest substrates. This review summarizes the recent advances in the fabrication of nanostructured materials with designed properties and functionalities by means of self-assembly of different guest substrates (such as metal oxide thin films, small molecules, polymers, biomacromolecules, nanoparticles, carbon nanotubes and colloidal spheres) on the surfaces of cellulose nanofibers of bulk natural cellulose substances. The combination of the specific chemical properties of the guest substrates and the unique physical features of the natural cellulose substances sheds new light on the design and syntheses of new functional nanomaterials.     

Aromatic condensation monomers and polymers containing quinoxal-2,3-diyl groups

The main achievements in the synthesis of aromatic condensation monomers and polymers containing quinoxal-2,3-diyl groups are surveyed. Two general approaches to incorporation of such groups into macromolecules are considered: (i) the synthesis of polymers with α-diketone groups (polybenzyls) followed by their polymer-analogous transformations under the influence of o-phenylenediamine and its derivatives and (ii) the synthesis of target polymers of various classes from monomers containing quinoxal-2,3-diyl groups. Particular attention is focused on the properties of the polymers of interest.     

Enzymatic oligomerization and polymerization of arylamines: state of the art and perspectives

The literature concerning the oxidative oligomerization and polymerization of various arylamines, e.g., aniline, substituted anilines, aminonaphthalene and its derivatives, catalyzed by oxidoreductases, such as laccases and peroxidases, in aqueous, organic, and mixed aqueous organic monophasic or biphasic media, is reviewed. An overview of template-free as well as template-assisted enzymatic syntheses of oligomers and polymers of arylamines is given. Special attention is paid to mechanistic aspects of these biocatalytic processes. Because of the nontoxicity of oxidoreductases and their high catalytic efficiency, as well as high selectivity of enzymatic oligomerizations/polymerizations under mild conditions—using mainly water as a solvent and often resulting in minimal byproduct formation—enzymatic oligomerizations and polymerizations of arylamines are environmentally friendly and significantly contribute to a “green” chemistry of conducting and redox-active oligomers and polymers. Current and potential future applications of enzymatic polymerization processes and enzymatically synthesized oligo/polyarylamines are discussed.     

Studies on Phosphorus-Containing Polymers. VI. Synthesis of Derivatives of Linear Phosphonitrile Chloride and Their Stability

The synthesis of LPNC and its derivatives and the hydrolysis and heat resistance properties of these materials are discussed. Lack of stability to water and depolymerization are adverse properties of many inorganic polymers. In the case of LPNC, it was found that these properties were probably due to the terminal ionic structure, and when the ionic part is removed from LPNC, the properties could be somewhat improved.     

Synthesis of soluble donor-acceptor double-cable polymers based on polythiophene and tetracyanoanthraquinodimethane (TCAQ)

[structure: see text] Novel suitably functionalized tetracyanoanthraquinodimethane (TCAQ) derivatives covalently linked to thiophene moieties have been synthesized. The thiophene-based monomers have been chemically polymerized and copolymerized to yield new and soluble donor-acceptor double-cable polymers. The absorption and emission data reveal that the optical properties can be finely tuned by modifying the ratio of monomers in the copolymerization process.     

Bicyclobutanes and cyclobutenes: Unusual carbocyclic monomers

Bicyclobutanes and cyclobutenes substituted with electron‐attracting groups represent novel classes of reactive monomers. They readily undergo free‐radical and anionic polymerizations to give high polymers consisting of 1,3‐ and 1,2‐enchained cyclobutane rings, respectively. They also copolymerize readily with conventional vinyl monomers. These polymers display numerous attractive properties in comparison with their vinyl counterparts, including enhanced thermal stability, superior optical properties, and higher glass‐transition temperatures. The syntheses of these monomers are reviewed, and suggestions toward future larger scale production are made. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 625–635, 2003     

Mobility of the ring structure and the characteristics of crosslinked polymers: The structural effect of the eleven-membered ring and its homologs upon the dynamic mechanical properties and glass transition temperature of crosslinked diallyl succinate polymers

Dynamic mechanical properties and glass transition temperatures were measured for crosslinked polymers derived from diallyl succinate monomers. The mobility of the diester having an eleven-membered ring and of homologous structures which are introduced in the crosslinked polymer system, is discussed on the basis of the parameter for cyclization polymerization of a monomer, dynamic mechanical properties, and glass transition temperature. Control of the mobility of the ring structure and its homologous structures involved in the crosslinked polymers was attempted by modification of the substituent at the 1- or 1,2-position of diallyl succinate, and the diallyl succinate monomers were derived from the succinic acid and its derivatives: succinic acid, methyl succinic, ethyl succinic, and chlorosuccinic acids; cis-1,2-dicarboxylic acids of cyclopropane, cyclobutane, cyclopentane, and cyclohexane; cis-1,3- and 1,4-dicarboxylic acids of cyclohexane, and phthalic acid. The results obtained are explained well on the basis of the mobility of the ring and homologous structures.     

基于β-环糊精的分子印迹聚合物在环境和食品样品前处理中的应用进展

β-环糊精（β-CD）及其衍生物作为一种新兴的功能单体在分子印迹技术中得到了越来越多的应用。β-CD及其衍生物能够与许多分子形成主-客体包合物,基于这一包合作用制备的分子印迹聚合物具有稳定性好和选择性高等优点,因此在具有复杂基质的环境和食品样品中目标化合物的选择性分离和富集中得到了重视和发展。该综述主要回顾了2013年以来文献中报道的一些基于β-CD及其衍生物作为功能单体的分子印迹聚合物在环境水和食品样品前处理方面的最新应用,揭示这一分子印迹聚合物在复杂样品前处理中的优势。     

Azulene in Polymers and Their Properties

Azulene, a unique isomer of naphthalene, has received much interest from researchers in different fields due to its unusual chemical structure with a negatively charged 5‐membered ring fused with a positively charged 7‐membered ring. In particular, incorporation of azulene into polymers has led to many interesting properties. This minireview covers functionalization methods of azulene at its various positions of 5‐ and 7‐membered rings to form azulene derivatives including azulene monomers, and gives an overview of a wide range of azulene‐containing polymers including poly(1,3‐azulene), azulene‐based copolymers with connectivity at 1,3‐positions of the 5‐membered ring, or 4,7‐positions of the 7‐membered ring, as well as copolymers with azulene units as side chains. Their chemical and physical properties together with applications of azulene‐containing polymers have also been summarized.     

Polyvinylamine at last

A sustained effort to develop and commercialize a practical radical addition route to amine functional polymers (AFPs) resulted, after almost 20 years, in the successful completion of a world scale monomer plant to produce N‐vinylformamide (NVF). NVF is readily polymerized and its polymers are easily hydrolyzed to reactive and atom economical polyvinylamine (PVAm) or its salts. This highlight touches on work by many companies, but focuses on efforts at Air Products and Chemicals, tracing the origins, rational, challenges, technical and commercial advances, and failures. Practical routes to new AFPs, copolymers, and derivatives across the entire molecular weight range (MW < 10³ to >10⁶) were achieved. NVF offers access to multiple water soluble, water dispersible, and nonwater soluble polymer markets, including papermaking additives and coatings, water treatment polymers, enhanced oil recovery polymers, radiation cure monomers, stabilizers, dispersing agents, surfactants, and crosslinkers. Lessons learned along the road to commercializing major new chemical technologies are also highlighted. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2257–2283, 2010     

Asymmetric polymerization of methacrylates

The syntheses of optically active polymers having helical conformation from bulky methacrylates are reviewed focusing on selected topics. The monomers include triphenylmethyl methacrylate and its analogues. Asymmetric anionic polymerization of the monomers gives isotactic, optically active polymers having a helical structure with excess helicity. The isotactic content and the extent of helical‐sense excess depend on the monomer structure and the reaction conditions. In the case of methacrylates, completely isotactic and single‐handed helical polymers can be produced by asymmetric anionic polymerization (helix‐sense‐selective polymerization). Asymmetric radical polymerization is also possible for this class of monomer. Some of the helical polymers show chiral recognition ability toward a wide range of racemic compounds. Polymers having main‐chain configurational chirality are also discussed.     

248 nm深紫外光刻胶用成膜树脂的研究进展

综述了用于248 nm化学增幅型深紫外光刻胶的不同种类和结构的成膜树脂,以及所使用单体的研发进展,包括聚甲基丙烯酸甲酯及其衍生物、聚对羟基苯乙烯及其衍生物、N取代的马来酰亚胺衍生物,以及其他聚合物等,对不同结构成膜树脂的曝光条件、对光刻胶性能的影响进行了介绍。     

Homogeneous and heterogeneous free radical polymerizations in environmentally responsible supercritical carbon dioxide

Fluoropolymers are used in many technologically demanding applications because of their balance of high-performance properties. A significant impediment to the synthesis of variants of commercially available amorphous fluoropolymers is their general insolubility in most solvents except chlorofluorocarbons (CFCs). The environmental concerns about CFCs can be circumvented by preparing these technologically important materials in supercritical fluids (SCFs). The homogeneous solution homo- and copolymerization of highly fluorinated acrylic, styrenic and olefinic monomers in supercritical carbon dioxide using free radical methods will be discussed [Science, 257 , 945 (1992)]. Detailed decomposition rates and efficiency factors will be presented for azobisisobutyronitrile (AIBN) in supercritical carbon dioxide and will be compared to conventional liquid solvents [Macromolecules, 26 , 2663 (1993)]. Additionally, viscosities of polymer solutions in supercritical CO₂ have been measured using a high pressure, falling cylinder viscometer. The results show that the polymer solution viscosities in supercritical CO₂ are an order of magnitude lower than with the same polymers in conventional organic solvents. The results from these homogeneous solution polymerization studies has allowed us to also consider heterogeneous polymerizations in a carbon dioxide continuous phase. Conventional emulsion polymerizations of unsaturated monomers are performed in either aqueous or organic dispersion media with addition of surface active agents (surfactants) to stabilize the colloidal dispersion that forms. With free radical initiators that are preferentially soluble in the continuous phase, high rates of polymerization and high molar mass polymers can be obtained simultaneously. Herein we describe an environmentally responsible alternative to aqueous and organic dispersing media for emulsion polymerizations which utilizes supercritical carbon dioxide, in conjunction with molecularly engineered free radical initiators and amphiphilic molecules that are specifically designed to be interfacially active in CO₂. Conventional lipophilic monomers, exemplified by methyl methacrylate and styrene, can be polymerized heterogeneously using a fluorinated azo-initiator in supercritical CO₂ in the presence of added surfactant to form stable emulsions that result in submicron size particles. Detailed surfactant and initiator syntheses and phase behavior will also be discussed.     

Synthesis of n‐alkyl methacrylate polymers with pendant carbazole moieties and their derivatives

New methacrylate monomers with carbazole moieties as pendant groups were synthesized by multistep syntheses starting from carbazoles with biphenyl substituents in the aromatic ring. The corresponding polymers were prepared using a free‐radical polymerization. The novel polymers contain N‐alkylated carbazoles mono‐ or bi‐substituted with biphenyl groups in the aromatic ring. N‐alkyl chains in polymers vary by length and structure. All new polymers were synthesized to evaluate the structural changes in terms of their effect on the energy profile, thermal, dielectric, and photophysical properties when compared to the parent polymer poly(2‐(9H‐carbazol‐9‐yl)ethyl methacrylate). According to the obtained results, these compounds may be well suited for memory resistor devices. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 70–76     

超(近)临界水中的化学反应

水作为自然界最常用的绿色介质在化学反应中已经得到广泛应用.近年来,随 着超临界技术的发展,人们对超(近)临界水的认识逐渐深入,以超(近)临界水为介质进 行化学反应的研究引起了人们的极大兴趣,开展了许多卓有成效的工作.本文在介绍超(近)临界水性质的基础上,主要对近年来超(近)临界水中的有机合成、无机化学反应、生物质的转化反应及聚合物的降解等方面的研究进展进行了回顾总结.     

Green synthesis of 3,4-disubstituted isoxazol-5(4H)-ones using ZnO@Fe3O4 core–shell nanocatalyst in water

An effective and environmentally benign methodology for the synthesis of isoxazol-5(4H)-one derivatives has been developed using a ZnO@Fe₃O₄ core–shell nanocatalytic system. The one-pot, multicomponent reaction of an aromatic/heterocyclic aldehyde, hydroxylamine hydrochloride and ethyl acetoacetate under aqueous conditions at slightly elevated temperature resulted in the formation of title compounds in extremely good yields. The present new protocol is environmentally friendly as it offers heterocyclization with some interesting promising features such as safety, atom efficiency, low cost, mild conditions, minimal waste, catalyst recyclability, water as a solvent, easy workup and possession of excellent functional group tolerance for the synthesisis of structurally diverse isoxazole derivatives. All products were characterized by spectral and analytical methods. A representative title derivative was studied for its structure by single crystal X-ray diffraction method.     

Metal-Free Twofold Electrochemical C−H Amination of Activated Arenes: Application to Medicinally Relevant Precursor Synthesis

The efficient production of many medicinally or synthetically important starting materials suffers from wasteful or toxic precursors for the synthesis. In particular, the aromatic non-protected primary amine function represents a versatile synthetic precursor, but its synthesis typically requires toxic oxidizing agents and transition metal catalysts. The twofold electrochemical amination of activated benzene derivatives via Zincke intermediates provides an alternative sustainable strategy for the formation of new C−N bonds of high synthetic value. As a proof of concept, we use our approach to generate a benzoxazinone scaffold that gained attention as a starting structure against castrate-resistant prostate cancer. Further improvement of the structure led to significantly increased cancer cell line toxicity. Thus, exploiting environmentally benign electrooxidation, we present a new versatile and powerful method based on direct C−H activation that is applicable for example the production of medicinally relevant compounds.