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1.
Novel polymeric derivatives bearing tributyltin carboxylate moieties in the side chain were synthesized. The coordination at tin in solution and in the solid state was investigated by both Sn‐NMR and FT‐IR: the metal atom appears completely tetracoordinated in chloroform solution, while in the solid state all polymeric products exhibit both tetra‐ and pentacoordination at tin, the latter increasing with the amount of tin containing units. No evidence of tin leaching by hydrolysis of the organometallic ester was observed for these materials. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5372–5383, 2004  相似文献   

2.
Three analogous series of symmetric banana-shaped liquid crystalline molecules containing bisnaphthyl units were synthesized and characterized. The effects of linking groups (on the side wings) and lateral meta-fluoro substitutions (on the middle outer rings) on the mesogenic properties were examined. The type of mesophase depends on the lengths of terminal alkoxy chains. Thus, achiral molecules with shorter flexible chains (n = 8) exhibit a rectangular columnar (B1) phase, while analogous derivatives with longer flexible chains (n = 12) display the B2 phase. All lateral meta-fluoro substituted analogues (series II) possess the lowest isotropization temperatures and the narrowest mesophasic ranges of the B1 and B2 phases. The B1 and B2 phases were confirmed by X-ray diffraction, polarizing optical microscopy (POM) and electro-optical (EO) switching experiments. An electric field-induced transition from an antiferroelectric (tristable) state to a ferroelectric (bistable) state was observed in the EO measurements. Spontaneous polarization (by switching current response), tilt angle of chiral domains (by POM), and transmittance-voltage measurements of the B2 phase in related compounds have been surveyed in this study.  相似文献   

3.
The synthesis and characterization of new metal-free 7 and metallophthalocyanines 8, 9 carrying macrocyclic N2S2O4 donor groups on peripheral positions have been investigated. Phthalonitrile derivative 6 was synthesized according to Rosenmund von Braun procedure from compound 5. The novel compounds were characterized by elemental analysis, IR, 1H and 13C NMR, UV-Vis and MS spectra data.  相似文献   

4.
Three novel 4,7-bis(n-pyridylethynyl)-2,1,3-benzothiadiazoles (n = 2, 3, and 4) were synthesized by using the Sonogashira cross-coupling reaction of 4,7-dibromo-2,1,3-benzothiadiazole with the corresponding ethynylpyridines in the presence of a Pd(II) catalyst. The viologen analogues were also prepared by methylation of pyridyl nitrogen atoms. X-ray structure analysis of these compounds revealed the linear molecular structures with unusual columnar crystal structures. Insertion of a benzothiadiazole moiety into the acetylene-pyridine skeleton brings about a large increase in electron affinity and the bispyridyl compounds obtained here show high fluorescence quantum yields.  相似文献   

5.
A series of new polybenzoxazines were synthesized based on diphenols containing (substituted) cyclohexyl moiety and were characterized by FT‐IR, 1H‐NMR, and 13C‐NMR spectroscopy. These new benzoxazine monomers exhibited better processability with lower peak cure temperature and a wide cure controllable window (CCW) as manifested in differential scanning calorimetric analysis. The cure analysis was performed by FT‐IR spectroscopy. Glass transition temperature of new polybenzoxazines varied from 170 to 205°C. The cyclohexyl bridge groups facilitated ring opening, resulting in polymer with improved thermal stability in comparison to bisphenol A‐based benzoxazine as assessed by the various thermal analyses. The water contact angles of polybenzoxazines containing (substituted) cyclohexyl moieties were higher than that of bisphenol A‐based polybenzoxazine, implying their higher hydrophobicity. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

6.
New styryl‐type water‐insoluble and methacryloyl‐type water‐soluble monomers, N‐(p‐vinylbenzyl)‐1,2‐O‐isopropylidene‐6‐D ‐glucofuranuronamide and N‐(2‐methacryloylamino)ethyl‐1,2‐O‐isopropylidene‐6‐D ‐glucofuranuronamide, were synthesized from the most common acidic saccharide, D ‐glucuronic acid. Their radical homopolymerizations and copolymerizations with styrene and acrylamide were tried under various conditions. The isopropylidene groups in the resulting polymers were removed in a mixture of trifluoroacetic acid and water (2/1 v/v) to give the corresponding polymers with many pendant D ‐glucopyranuronyl groups with reactive reducing groups. The pendant reducing ends may be useful as potential binding sites under a hydrophilic atmosphere. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3893–3901, 2001  相似文献   

7.
New polyamides, containing a benzimidazole side group and ethylene oxide moieties in the structural repeat unit, were synthesized by low‐temperature polycondensation. The aim of this design was to obtain polyamides that were more soluble in common organic solvents and hence had better processability than benzimidazole polyamides while maintaining the water sorption properties characteristic of the latter. The results showed that the number of ether linkages of the repeat unit played an important role in the glass‐transition temperature and in the water sorption properties, the polyamides with one or two ethylene oxide units being more hydrophilic than benzimidazole polyamides. However, the length of the ethylene oxide chain played a minor role in the solubility because the second member of the series, with two ether linkages (i.e., one ethylene oxide unit), reached the same level of solubility as those polyamides with more ethylene oxide moieties. No crystallinity was observed by X‐ray and calorimetric measurements for the new polymers. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 112–121, 2005  相似文献   

8.
<正>Two new cage compounds,4-trinitroethyl-10-nitro-2,6,8,12-tetraacetylhexaazaisowurtzitane(3) and 4-trinitroethyl- 2,6,8,10,12-pentanitrohexaazaisowurtzitane(4),containing trinitromethyl group were synthesized by a novel method,and their structures were confirmed by IR,~1H NMR,MS and single crystal X-ray.DSC result shows that compound 4 has surprising thermal stability and could be a potential energetic compound.  相似文献   

9.
High molecular weight polyetheresters (PEE) containing thermally curable benzoxazine units in the main chain have been synthesized. For this purpose, first the diol functional monomer is synthesized through the Mannich reaction of 4,4′‐isopropylidenediphenol (bisphenol A), formaldehyde, and 2‐(2‐aminoethoxy)ethanol. Polycondensation of the resulting benzoxazine dietherdiol with adipoyl chloride and terephthaloyl dichloride in the presence of triethyl amine yields the corresponding PEE with the molecular weights of 34.000 Da. The structures of the precursor diol monomer and the resulting PEEs are confirmed by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy (1H‐NMR) analysis. Curing behavior of both the monomer and polymers has also been studied by differential scanning calorimetry (DSC). Flexible free standing transparent films of the PEEs are obtained by solvent casting from dichloromethane solution on Teflon plates. The films preserve shape and, to some extent, toughness after thermal curing between 140 and 220 °C. Thermal properties of the cured polymers are also investigated by thermogravimetric analysis (TGA). © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 414–420, 2008  相似文献   

10.

Reaction of adenine and 9-[2-(1,3-dioxolan-2-yl)ethyl]-9H-purine-6-amine with ethylidene-1,1-bisphosphonates resulted in the formation of new purine bases containing ethylidene-1,1-bisphosphoryl groups.

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11.
A series of new AB-type poly(etherimide)s having bisphenol-type moiety was prepared by the one-pot polyimidization using triphenylphosphite(TPP) in N-methyl-2-pyrrolidone(NMP)/pyridine solution at 150°C. Complete cyclodehydration was observed in the polymerizations as well as in model reactions. Polymers were obtained with inherent viscosities in the 0.27–0.49 dL/g range. The Mn and Mw/Mn of poly[4-(1,4-phenyleneoxy-1,4-phenylenehexafluoro-isopropylidene-1,4-phenylene)oxyphthalimide] (4d) with ηinh = 0.49 dL/g were 73,400 g/mol and 1.5, respectively. Most polymers could readily be dissolved in common organic solvents such as DMAc, NMP, and m-cresol. The polymer 4d was soluble even in chloroform. These polymers had glass transition temperatures between 205 and 235°C, and 5% weight loss temperatures in the range of 511–532°C in nitrogen. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3530–3536, 1999  相似文献   

12.
A new disubstituted polyacetylene with indolylazo moieties in its side chains ( 9 ) was synthesized by a post functionalization strategy, which was difficult, or perhaps impossible, to obtain from the direct polymerization of its corresponding monomer. The polymer is soluble in common solvents and thermally stable. The polymer shows good optical transparency with an absorption maximum at 393 nm and a band edge at ~530 nm. Its poled film exhibits a resonant d33 value of 17.9 pm/V and its optical nonlinearity is resistant to thermal decay at up to 147 °C. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5672–5681, 2006  相似文献   

13.
New coumarin derivatives, namely (2-(4-methyl-2-oxo-2H-chromen-7-yloxy)-N-(4-oxo-2-phenylthiazolidin-3-yl)acetamide, N-(2-(3-methoxyphenyl)-4-oxothiazolidin-3-yl)-2-(4-methyl-2-oxo-2H-chromen-7-yloxy)acetamide, 2-(4-methyl-2-oxo-2H-chromen-7-yloxy)-N-(4-oxo-2-(2,3,4trimethoxyphenyl)thiazolidin-3-yl)acetamide and N-(2-(4-bromophenyl)-4-oxothiazolidin-3-yl)-2-(4-methyl-2-oxo-2H-chromen-7-yloxy)acetamide) were synthesized starting from 4-methyl-7-hydroxycoumarin. The structures of the obtained compounds were confirmed by analytical IR and NMR spectra to elucidate the different positions of protons and carbons and as well as theoretical studies (DFT/B3LYP). The new compounds were screened for antibacterial activity. Most of them are more active against E. coli S. aureus and B. subtilis than standard references.  相似文献   

14.
This work synthesized a series of new polyamides by direct polycondensation of 1,3-bis[4-(4-carboxyphenoxy)phenyl]adamantane ( I ) with various diamines. The diacid I was synthesized from 1,3-bis(4-hydroxyphenyl)adamantane in two steps. Polyamides III were soluble in N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc), and pyridine. The polyamides had medium inherent viscosities of 0.30–0.55 dL/g and number-average molecular weights (Mn) of 22,000–36,000. The polyamides III a and III b had tensile strengths of 59.8 and 77.5 MPa, elongation to breakage values of 5.8 and 7.6%, and initial moduli of 1.9 and 1.8 GPa, respectively. Their glass transition temperatures were found to be 219–295°C by means of differential scanning calorimetry (DSC). Dynamic mechanical analysis (DMA) reveals that the incorporation of rigid and bulky diamantane into polyamides III a and III b leads to high glass transition temperatures (Tgs), at 299 and 286°C, respectively. The decomposition temperatures of polyamides III at a 5% weight loss ranged from 388 to 416°C in air and from 408 to 435°C in N2 atmosphere. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 785–792, 1998  相似文献   

15.
A simple, efficient, and general method has been developed for the synthesis of various alpha-aminophosphonate derivatives 4a-4l by treatment of substituted benzaldehydes and aniline with bis(2-methoxyethyl)- or bis(2-ethoxyethyl) phosphite under microwave irradiation without solvents and catalysts. The products were characterized by elemental analysis, IR, 1H-NMR, 13C- and 31P-NMR spectra. The X-ray crystallographic data of the representative compound 4l was determined. The new alpha-aminophosphonate derivatives were found to possess moderate to good antiviral activity.  相似文献   

16.
17.
A series of peptide-like 25–28 membered macrocycles containing 1,3,4-oxadiazoles and pyridines bearing a chiral center scaffold have been synthesized by using known coupling reagents and common protecting groups. The yield of the purified macrocycles was poor on an average, yet it seems to be independent of amino acid substitution or stereochemistry. These macrocycles represent a new class of structures for further development and for future application in high-throughput screening against a variety of biological targets.  相似文献   

18.
3‐Aminopyridazines 17 and 3‐hydrazinopyridazines 18 were used as building blocks for the preparation of various types of functionalized, pyridazine ring containing compounds. 3‐Aminopyridazines were employed in the synthesis of 3‐(6‐chloroimidazo[1,2‐b]pyridazin‐2‐yl)alanines 26, 27 and for the preparation of 3‐amino‐4H‐pyrimido[1,2‐b]pyridazin‐4‐ones 103 , intermediates in the ‘ring switching’ synthesis of alkyl 1‐pyridazin‐3‐yl‐1,2,3‐triazole‐4‐carboxylates 106 .On the other hand, hydrazinopyridazines 18 were employed in a two‐step preparation of 3‐functionalized 1,2,4‐triazolo[4,3‐b]pyridazines via condensation with functionalized aldehydes and their enamino analogs followed by oxidative cyclization of the intermediate hydrazones. In this manner, 1,2,4‐triazolo[4,3‐b]pyridazin‐3‐yl substituted alanines 29, 30 , polyols 33, 39–48 , C‐nucleosides 49, 50 , and terpenes 58, 62, 64–69 were prepared. In another general approach, 3‐hydrazinopyridazines 18 were treated with functionalized enaminones as 1,3‐dielectrophiles to give the 1‐(substituted pyridazin‐3‐yl)‐1H‐pyrazole derivatives containing an ester 72, 73, 75, 76 , alanine 79, 84, 85, 87 , 2‐phenylethylamine 97, 99 , and β‐amino alcohol functional element 98, 100 . In the reaction of 4‐oxohomoglutamate 82 with hydrazine hydrate and methyl hydrazine, chiral functionalized tetrahydropyridazinones 88a,b were obtained.  相似文献   

19.
An overview of the structure and biological activity of macrocyclic polyketides derived from dinoflagellates that contain unusual cyclic imine units is provided. The total and partial syntheses of these molecules are discussed with an emphasis on the construction of the spiroimine functionality thought to be the key pharmacophore of these fact-acting shellfish toxins.  相似文献   

20.
Alkyl 2-cyano-3-methylthio-3-phosphonylacrylates were synthesized by the reaction of alkyl 2-cyano-3,3-dimethylthioacrylates with dialkyl phosphites. The structures of the new compounds were characterized by elemental analyses, IR, 1H-, 13C- and 31P-NMR spectral data. These compounds were tested in vitro against pathogenic fungi, namely, Fusarium graminearum, Cytospora mandshurica and Fusarium oxysporum. Amongst all compounds, 2d and 2t were found to be effective against the tested fungi at 50 microg/mL. A half-leaf method was used to determine the in vivo protective, inactivation and curative efficacies of the title products against tobacco mosaic virus (TMV). Title compounds 2a and 2b were found to possess good in vivo curative, protection and inactivation effects against TMV with inhibitory rates at 500 mg/L of 60.0, 89.4 and 56.5 and 64.2, 84.2 and 61.2 %, respectively. To the best of our knowledge, this is the first report on the antiviral and antifungal activity of alkyl 2-cyano-3-methylthio-3-phosphonylacrylates.  相似文献   

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