Synthesis of soluble,branched polyphenyls

The cotrimerization of phenylacetylene and diethynylbenzene yields high molecular weight highly branched polyphenyls. The polymers obtained have the usual thermal stability. They are soluble in common chlorinated solvents.     

Synthesis and nonlinear optical properties of a novel indium phthalocyanine highly branched polymer

Due to the well‐known optical limiting properties of indium (III) phthalocyanines (In [III] Pcs) and aiming at extending their conjugation system, a highly branched indium phthalocyanine polymer was prepared. Flash chromatography was used for obtaining a pure polymer of polydispersity index near to the unity. The structure of the prepared polymer was determined using different spectroscopic techniques. Optical limiting and open aperture Z‐scan measurements were carried out according standard procedures. Compared with many other phthalocyanines, the prepared indium‐phthalocyanine polymer shows a high optical limiting performance that is indicated by a relatively low limiting threshold of 430 mJ cm^?2 and a large nonlinear absorption coefficient (α₂ = 3.4 × 10^?8 cmW^?1). Copyright © 2015 John Wiley & Sons, Ltd.     

Photochemistry on soluble polymer supports: synthesis of nucleosides

[reaction: see text] A new soluble polymer support synthesis of nucleosides is described. The photochemical ring expansion of cyclobutanones in the presence of poly(ethylene glycol) (PEG) results in polymer-supported ribosides. These photoadducts can be cleaved from the polymer under Vorbrüggen coupling conditions with TMS-protected purines and pyrimidines to give ribonucleosides. The method has been extended to include modified PEGs with dendritic end-groups in order to improve the loading levels for these coupling reactions.     

Synthesis of well-defined soluble polystyrene supports: Impact of polymer chain on grafted organotin reagent activity

The synthesis of well-defined soluble polystyrene supports bearing tin hydride functionalities has been achieved in two steps. First, a precursor was prepared by copolymerization of styrene and acetoxystyrene using atom transfer radical polymerization. Prior any modification, this precursor was fully characterized to check its structure. Then in a second part, tin hydride functions were introduced by a four step process. The chemical modification was monitored by IR and ¹H NMR spectroscopies. The soluble support was also characterized by triple detection size exclusion chromatography at each step. Two families of supports were synthesized by varying the molecular weight and the degree of functionalization. The effectiveness of these tin hydride supports was tested through the reduction of 6-bromohexene and compared with the small counterpart Bu₃SnH. Measurements of rate constant for hydrogen transfer were also reported.     

"Inverse" synthesis of polymer bioconjugates using soluble supports

Well-defined cleavable or non-cleavable soluble polystyrene supports were prepared by atom transfer radical polymerization and utilized for the iterative synthesis of functional hexapeptides. This approach allowed rapid and efficient liquid phase synthesis of peptide-polymer conjugates.     

可溶性聚合物在有机合成中的应用研究

概述了液相合成中所使用的可溶性聚合物性质、类型、特点,以及可溶性聚合物在合成肽、低聚苷酸、寡糖、杂环化合物、催化剂、试剂及小分子物质等方面的应用。     

Synthesis of a nonionic water soluble semiconductive polymer

A new nonionic water-soluble fluorescent conjugated polymer is reported with hydroxyl and amide side chains surrounding an aromatic polymer backbone.     

Synthesis of soluble branched polyimides derived from an ABB′ monomer

A novel ABB′ monomer, an isomeric mixture of 4‐[4‐(2,4‐diaminophenoxy)phenoxy]phthalic acid 2‐methyl ester, was successfully prepared. The direct polycondensation of the ABB′ monomer was carried out to form polyamic acid monomethyl ester as a precursor with an inherent viscosity of 0.30 dL/g and a number‐average molecular weight of 12,000. The degree of branching of the precursor, determined by ¹H NMR, was 0.07. The low degree of branching was caused by the differences in the reactivities of the amino groups. The shape factor was calculated to be 0.72. End‐modified reactions with acetyl chloride, benzoyl chloride, and phthalic anhydride were carried out. After the chemical imidization of the end‐modified precursors, end‐modified polyimides were successfully prepared. The end‐modified polyimides were soluble in dimethyl sulfoxide, dimethylformamide (DMF), and N‐methyl‐2‐pyrrolidinone. On the basis of thermogravimetry and differential scanning calorimetry measurements of the polyimides, the 5 wt % thermal loss temperatures were determined to be 400–520 °C, and the glass‐transition temperatures were determined to be 200–258 °C. According to the X‐ray diffraction measurements, the end‐modified polyimides were amorphous. A strong but brittle film was prepared from an acetamide end‐modified polyimide solution, via casting from a DMF solution, with a tensile strength of 46 MPa, an elongation at break of 4%, and a modulus of 1.3 GPa. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3200–3211, 2004     

Synthesis,characterization and application of soluble fullerenated polymer materials

This article only deals with the topic of intense interest to us and to a considerable extent of our own experimental results on the synthesis,characterization and application of C60-con-taining functional polymers such as poly(N-vinylcarbazole),polystyrene and polyacrylonitrile-based fullerene polymers.The results demonstrate that [60] fullerene can be directly incorporated into a variety of functional polymers by copolymer-ization or grafting,but also can be used to modify or improve the electronic,optical and physicochemical properties of polymers.Both the stereo-electroniceffect and the steric hindrance of C60 have an important influence on the structure and physicochemical properties of the parent polymer.     

Fullerene-containing branched polymethacrylates and polymer networks: Synthesis,structure, and properties

Branched poly(methyl methacrylates) containing covalently and noncovalently attached fullerene C₆₀ are synthesized and characterized by IR and UV spectroscopy. The basic physicochemical characteristics of the branched poly(methyl methacrylate) comprising covalently attached fullerene and the non-functionalized branched polymer of the same composition are compared. The effect of fullerene-containing branched poly(methyl methacrylates) on the kinetics of the crosslinking radical polymerization of 1,6-hexanediol dimethacrylate and on the structural-physical (mechanical, thermomechanical, and diffusion-sorption) properties of the resulting polymers is examined. The role of fullerene attached to the branched poly(methyl methacrylate) as an inhibitor of the crosslinking radical polymerization of dimethacrylate and as a modifier of the structure and properties of the polymers is ascertained.     

Synthesis of heparin-like oligosaccharides on a soluble polymer support

Based on previously developed solution phase chemistry, an effective general approach to the synthesis of heparin-like oligosaccharides on a soluble polymer support is reported.     

Parallel synthesis of novel benzimidazoles on a soluble polymer support

Liquid phase combinatorial synthesis using a soluble polyethylene glycol (PEG) polymer support and commercially available 3-nitro-4-fluoro benzoic acid is carried out in order to create a molecular library of trisubstituted benzimidazoles. The PEG-ester conjugate of 3-nitro-4-fluoro benzoic acid is subjected to ipso-fluoro displacement by various primary amines. The nitro group is reduced under neutral conditions using excess zinc and ammonium chloride, producing the polymer-boundo-phenylene diamines. Reaction of the diamines with different aldehydes results in cyclisation to benzimidazoles. The polymer support is cleaved releasing the desired products in high yields and purity. All reactions are performed at room temperature.      

Synthesis and investigation of new water soluble sulfonated rigid-rod polynaphthoyleneimide

A new water-soluble rigid-rod sulfonated polynaphthoyleneimide (PNIS) was synthesized. The structure of PNIS has been confirmed by elemental analysis, NMR (¹H, ¹³C), full X-ray investigation of model compound. Viscosity measurements, sedimentation and light-scattering experiments of PNIS solutions confirm the suggested aggregation of this polymer and an increase of its molecular weight without being substantially changed in different types of aqueous solution. These aggregates could consist of very tightly packed rigid rods.     

Synthesis of oligosaccharides on soluble high-molecular-weight branched polymers in combination with purification by nanofiltration

[structure: see text] An efficient approach for polymer-supported oligosaccharide synthesis is described whereby branched and high-molecular-weight PEG derivatives are used in combination with purification by nanofiltration. This methodology was applied to the preparation of a tetraglucoside and the tumor-associated antigen Le(x).     

Simulation studies of branched polymer molecules

Monte Carlo simulation results are presented for lattice models of uniform stars (one branch point of functionality f = 3), combs (two branch points, ? = 3,3) and brushes (two branch points ? = 3,4 and ? = 3,5). We estimate the critical exponent γ(?), the ratio g(?) = 〈S(?)〉/〈S(1)〉 (where 〈S(?)〉 is the mean-square radius of gyration of a structure having ? branches and N monomers), and the meansquare end-to-end branch lengths, as a function of the number and arrangement of branches. Comparisons with theoretical predictions and experimental data are made where possible, leading to a test of some predictions, and a suggestion concerning future experiments.     

Synthesis of a novel branched cyclophosphazene-PEPA flame retardant and its application on polypropylene

Journal of Thermal Analysis and Calorimetry - A phosphorous–nitrogen containing cyclophosphazene derivative intumescent flame retardant with branched structures, named...     

Synthesis and evaluation of poly(oxyethylene glycol) polymer (POP) supports

Mono- and alpha,omega-bis-styryl-oligo(oxyethylene glycol) ethers have been constructed in an efficient two-step synthesis. From these precursors, poly(oxyethylene glycol) polymer (POP) supports of varying monomer and cross-linker composition have been produced. The swelling properties and mass-solvent uptake of these novel materials have been evaluated in a variety of solvents, demonstrating that POP supports exhibit enhanced solvent compatibilities over the commercial resins TENTA-GEL, ARGO-GEL, and Merrifield's resin. The utility of POP supports in solid-phase organic chemistry has also been demonstrated successfully. It is anticipated that these high-loading polymeric supports will have generic application in the solid-phase synthesis of combinatorial libraries and the in situ screening of these libraries in the aqueous environment of a bioassay.