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1.
4-(Succinimido)-1-butane sulfonic acid as a efficient and reusable Brönsted acid catalyzed the synthesis of 4,4′-(arylmethylene)bis(1H-pyrazol-5-ol) derivatives under solvent-free conditions. The catalyst can be prepared by mixing succinimide and 1,4-butanesultone that is simpler and safer than the preparation of succinimide sulfonic acid. This method has the advantages of high yield, clean reaction, simple methodology, and short reaction time. The catalyst could be recycled without significant loss of activity.  相似文献   

2.
1,1′-butylenebis(3-methyl-3H-imidazol-1-ium) hydrogen sulfate as an efficient, halogen-free, and reusable binuclear Brönsted ionic liquid catalyzed the synthesis of ethyl-4-aryl/heteryl-hexahydro-trimehtyl-5-oxoquinoline-3-carboxylates by the one-pot condensation of dimedone, aryl/heteryl aldehydes, ethyl acetoacetate, and ammonium acetate under solvent-free conditions. This method has the advantages of high yields, clean reaction, simple methodology, and short reaction time. The ionic liquid could be recycled and reused four times without significant loss of in the catalytic activity.  相似文献   

3.
V. Percec  S. Okita  J. Bae 《Polymer Bulletin》1992,29(3-4):271-276
Summary The synthesis and Ni(0) catalyzed homocoupling polymerization of 4,4-bis[5-(trifluoromethanesulfonyloxy)-2-biphenylyl]-1, 1-binaphthyl (9) are described. This polymerization reaction produces a soluble polyarylene containing alternating 4,4-(1,1-binaphthyl) and 4,4-(3,3-diphenyl)biphenyl structural units.  相似文献   

4.
The oxidative polycondenzation reaction conditions of N, N-bis (2-hydroxy-1-naphthalidene) thiosemicarbazone (HNTSC) using air oxygen, H2O2 and NaOCl were studied in an aqueous alkaline medium between 50–90°C. Oligo-N, N-bis (2-hydroxy-1-naphthalidene) thiosemicarbazone was characterized by 1H-NMR, FT-IR, UV-Vis, size exclusion chromatography (SEC) and elemental analysis techniques. Solubility testing of oligomer was investigated using organic solvents such as DMF, THF, DMSO, methanol, ethanol, CHCl3, CCl4, toluene acetonitrile, ethyl acetate, concentrated H2SO4 and an aqueous alkaline solution. Using NaOCl, H2O2 and air O2 oxidants, conversion to oligo-N, N-bis (2-hydroxy-1-naphthalidene) thiosemicarbazone (OHNTSC) of N, N-bis (2-hydroxy-1-naphthalidene) thiosemicarbazone was found to be 85, 80 and 76%, respectively, in an aqueous alkaline medium. According to the SEC analyses, the number-average molecular weight, weight-average molecular weight and polydispersity index values of OHNTSC synthesized were found to be 1050 gmol–1 1715 gmol–1 and 1.63, using NaOCl, and 2137, 2957 gmol–1 and 1.38, using air O2 and 2155 gmol–1 4164 gmol–1 and 1.93, using air H2O2, respectively. Also, TG analysis was shown to be unstable of oligo-N, N-bis (2-hydroxy-1-naphthalidene) thiosemicarbazone against thermo-oxidative decomposition. The weight loss of OHNTSC was found to be 97.29% at 900°C.  相似文献   

5.
1,4-bis(1-Methyl-1-silacyclobutyl)benzene (I) has been prepared by the reaction of 1-chloro-1-methyl-1-silacyclobutane with the di-Grignard reagent prepared fromp-dibromobenzene. In a similar manner, co-oligo(1-silacyclobut-1-ylidene-1,4-phenylene) (II) and co-oligo(1-silacyclobut-1-ylidene-4,4′-biphenylene) (III) have been prepared by condensation oligomerization between 1,1-dichloro-1-silacyclobutane and the di-Grignard reagents prepared fromp-dibromobenzene and 4,4′-dibromobiphenyl, respectively. These have been characterized by1H,13C, and29Si NMR as well as FT-IR and UV spectroscopy. The molecular weight distributions of these co-oligomers have been determined by GPC. Their thermal stabilities have been evaluated by TGA. Thermal degradation of these co-oligomers in nitrogen gives high (60%) char yields. The stability of these chars in air has been determined. TheT g's of these co-oligomers have been measured by DSC. Platinum-catalyzed ring opening of the silacyclobutane rings ofI,II, andIII cross-links these to thermoset materials. The bending moduli (logE′), tan δ, andT g's of these materials have been determined by DMTA. The dielectric constant and dissipation factor of cross-linkedII are reported.  相似文献   

6.
Condensation products of 5-substituted phenyl-2-furoyl hydrazide with different monosaccharides d-glucose, d-galactose,d-mannose, d-fucose and d-arabinose were prepared. The anomerization and cyclic-acyclic isomers were investigated by 1H NMR spectroscopy. The results showed that, except for the d-glucose derivatives, which were in the presence of β-anomeric forms, all derivatives were in an acyclic Schiff base form. Their antifungal and antitumor activities were studied. The bioassay results indicated that some title compounds showed superior effects over the commercial positive controls.  相似文献   

7.
ABSTRACT

In this article a simple, rapid, green and efficient method for the synthesis of various 1′Hspiro[isoindoline-1,2′-quinazoline]-3,4′(3′H)-diones in the presence of acidic magnetic graphene oxide nanosheets (Fe3O4–GO–SO3H) as catalyst is reported. Different substituted spirooxindoles have been synthesized from one-pot three component reaction of isatoic anhydride, aliphatic or aromatic primary amines and isatin in the presence of Fe3O4–GO–SO3H. This reaction allowed us to prepare some new and known derivatives of substituted spirooxindoles. The worthwhile advantages of this method are high product yields, short reaction times, the possibility of using of a magnetic, reusable and non-toxic catalyst and solvent-free conditions.  相似文献   

8.
A new soluble luminescent poly[2-decyloxy-5-(2′,5′-bis(decyloxy)phenyl)-1,4-phenylenevinylene] (DBDP-PPV) is prepared by the dehydrohalogenation of 1,4-bis(bromomethyl)-2-decyloxy-5-(2′,5′-bis(decyloxy)phenyl) benzene (as monomer) in this study. The above monomer bearing decyloxy and 2′,5′-bis(decyloxy)phenyl substituents was prepared via such chemical reactions as alkylation, bromination, and Suzuki coupling reactions. The two asymmetric substituents on the phenylene ring make the DBDP-PPV soluble in organic solvents and eliminate the tolan-bis-benzyl (TBB) structure defects. The structure and properties of the DBDP-PPV are examined by 1H-NMR, FT-IR, UV/Vis, TGA, photoluminescence (PL), and electroluminescence (EL) analyses. The DBDP-PPV film exhibits a PL peak at 519 nm. With the DBDP-PPV acting as a light-emitting polymer, a device is fabricated with a sequential lamination of ITO/PEDOT/DBDP-PPV/Ca/Ag. The EL spectrum of the device shows a maximum emission at 507 nm. The turn on voltage of the device is about 15.6 V. Its maximum brightness is 4.67 cd/m2 at a voltage of 16.8 V.  相似文献   

9.
1,1′-Butylenebis(3-methyl-3H-imidazol-1-ium) hydrogen sulfate as an efficient, halogen-free and reusable Brönsted ionic liquid catalyzed the synthesis of 13-(aryl)-12H-benzo[f]indeno[1,2-b]quinoline-12-one derivatives in ethanol under refluxing conditions. This method has the advantages of high yield, clean reaction, simple methodology, and short reaction time. The ionic liquid catalyst could be recycled and reused seven times without significant loss of activity. The structures of the new compounds were confirmed by IR, 1H NMR, 13C NMR and elemental analysis.  相似文献   

10.
The acid-catalyzed dimerization of α-methyl styrene led to the formation of trimethyl phenyl indane, which on nitration followed by reduction using hydrazine hydrate gave 5(6)-amino-1(4′-aminophenyl)-1,3,3′-trimethyl indane. This aromatic diamine was used to synthesize bismaleamic acid and imidized to yield bismaleimide. The bismaleamic acid was converted to prepolymer directly by imidizing it in refluxing toluene. All the materials synthesized were characterized using FTIR, 1H and 13C NMR. The direct inlet mass spectral characterizations were carried out for bismaleamic acid, bismaleimide and bismaleimide prepolymer. The fragmentation pattern was discussed in detail and the structure proposed was confirmed. The thermogravimetric studies were done for all the materials and kinetic parameters (energy of activation and frequency factor) were calculated using Dharwadkar and Kharkhanavala method. The structural changes occurring in the thermally polymerized bismaleimide and bismaleimide prepolymer were discussed.  相似文献   

11.
A new kind of polysiloxane containing N,N′-bis(diphenylsilyl)tetraphenylcyclodisilazane was prepared by the anionic polymerization with a “seed solution” as initiator. The synthesis of monomers N,N′-bis(hydroxydiphenylsilyl)tetraphenylcyclodisilazane (BHPTPC), N,N′-bis(chlorodiphenylsilyl)tetraphenylcyclodisilazane (BCPTPC), and 1,3-dichloro-1,1,3,3-tetraphenyldisilazane (DCTPS) are all reported in this study. The synthesized polysiloxane containing N,N′-bis(diphenylsilyl)tetraphenylcyclodisilazane was characterized by 1H–NMR, 29Si–NMR, gel permeation chromatography (GPC), and intrinsic viscosity. The thermal stability of the polysiloxane was studied by isothermal gravimetric analysis (IGA). The results demonstrated that the synthesized polysiloxane containing N,N′-bis(diphenylsilyl)tetraphenylcyclodisilazane had excellent thermal stability. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 929–933, 2001  相似文献   

12.
A series of poly(ester imide) (PEsI) copolymers were synthesized using 3,3′,4,4′-biphenyltetracarboxylic dianhydride (4,4′-BPDA), 2,2′-bis(trifluoromethyl)benzidine (TFMB), and 4-aminophenyl-4′-aminobenzoate (APAB) as the monomers. Wide-angle x-ray diffraction results revealed that the average interchain distances of these polymers ranged from 4.6 to 5.7 Å, increasing with the increase of TFMB contents. PEsI-0.3 and PEsI-0.4 exhibited a glass transition temperature (Tg) of 445 and 455°C, respectively, while no distinctive Tg was observed for the PEsI copolymers when the APAB content was >50 mol%. The coefficients of thermal expansion (CTE) of these PEsI copolymers ranged from 3.8 to 24.2 ppm K−1, increasing with the increase of TFMB contents. The PEsI copolymers exhibited a modulus of 5.7–7.8 GPa, a tensile strength of 282–332 MPa, and an elongation-at-break of 10.2%–23.3%. Furthermore, these copolymers exhibited a dielectric constant of 2.53–2.76, and a low dissipation factor (Df) of 0.0026–0.0032 at 10 GHz in dry state. Because of their excellent combined properties, these PEsI copolymers are promising candidates as dielectric substrate materials for the applications in next generation flexible printed circuit boards operating at high frequencies.  相似文献   

13.
One new title compound [Mn3(BIBP)(sdb)(NO2)2(H2O)2]n·2DMF (1) (BIBP = 4,4′-bisimidazolylbiphenyl, sdb = 4,4′-sulfonyldibenzoic acid) has been synthesized under hydrothermal condition. The title compound was characterized by IR spectra, thermal analysis, single crystal and powder X-ray diffraction. Magnetic susceptibility measurements indicate that compound 1 exhibits antiferromagnetic coupling interaction.  相似文献   

14.
本文提出了由间氨基酚与4,4′-二氯二苯砜反应合成了一种新型的芳香族胺类固化剂。有关反应温度、原材料配比等因素对反应的影响都进行了详尽的研究。  相似文献   

15.
Abstract

The thermal stability and the kinetic parameters of a series of polyesters were studied by non-isothermal thermogravimetry. The thermal decomposition temperatures (TDT) depend principally on the nature of the diphenols, in the sense that when the bulk of the diphenol is increased, the TDT values decrease. The kinetic parameters, determined using the Arrhenius relationship, show that these polyesters degrade by a complex mechanism or possibly two or more superimposed processes, probably due to the complex structure of both diacids and diphenols.  相似文献   

16.
A diamine monomer, 4,4’-bis(5-amino-2-pyridinoxy)benzophenone, was designed and synthesized, and used to react with commercially different kinds of aromatic dianhydrides to prepare a series of polyimides containing pyridine and ketone units via the classical two-step procedure. Glass transition temperatures (Tg) of the resultant polyimides PI-(1–5) derived from 4,4’-bis(5-amino-2-pyridinoxy) benzophenone with various dianhydrides ranged from 201 to 310 °C measured by differential scanning calorimetry. The temperatures for 5%wt loss of the resultant polyimides in nitrogen atmosphere obtained from the thermogravimetric analysis curves fell in the range of 472–501 °C. The temperatures for 10%wt loss of the resultant polyimides in nitrogen atmosphere fell in the range of 491–537 °C. Meanwhile, the char yields at 800 °C were in the range of 55.3–60.8%. Moreover, the moisture absorption of polyimide films was measured in the range of 0.37–2.09%. The thin films showed outstanding mechanical properties with tensile strengths of 103–145 MPa, an elongation at break of 12.9–15.2%, and a tensile modulus of 1.20–1.88 Gpa, respectively. The coefficients of thermal expansion of the resultant polyimides were obtained among 26–62 ppm °C?1. To sum up, this series of polyimides had a good combination of properties applied for high-performance materials and showed promising potential applications in the fields of optoelectronic devices.  相似文献   

17.
A new metal–organic framework {[Cd(L)(4,4′-bpy)]2·5H2O} n (1) had been synthesized by hydrothermal reaction of 5-(oxidediphenylphosphino)isophthalic acid, Cd(II) nitrate, NaOH and 4,4′-bipyridine (4,4′-bpy) as co-ligand. The novel compound was characterized by single crystal X-ray diffractometry as well as FTIR spectrum. Adjacent eight-member (C2Cd2O4) rings are connected each other through pairs of L2? ligands to result in a 1D double chain. Such ribbons are interconnected together by 4,4′-bpy to generate a 2D pillared layer, which are further held together by rich O–H···O hydrogen bonds to give a 3D supramolecular network. Solvent water molecules play an important role to bridge adjacent layers to form a 3D supramolecular architecture. The luminescence property and thermogravimetric analysis of title complex were investigated.  相似文献   

18.
As described in this article, 4,4′-bis(chloromethyl)biphenyl was obtained in 85% excellent yield by chloromethylation of biphenyl catalyzed by the recyclable temperature-dependant phase-separation system that comprised the dicationic acidic ionic liquid PEG1000-DAIL and methylcyclohexane under homogeneous catalysis in aqueous media. Compared to other synthetic methods, the novel method not only enhanced the yield, but also made the operating units easy workup. The mechanism of chloromethylation reaction and the process of catalysis in the thermoregulated ionic liquid bi-phase system were proposed.  相似文献   

19.
The synthesis and structural characterization of four novel triorganotin(IV) complexes, {(R3Sn)2[C2H4S(COO)2]} n (R = Me: 1), {(R3Sn)4[C2H4S(COO)2]2} n (R = nBu: 2), {(R3Sn)2[C4H8S(COO)2]} n (R = Me: 3; nBu: 4) were obtained by the reaction of 2,2′-thiodiglycolic acid, 3,3′-thiodipropionic acid and the corresponding R3SnCl (R = Me, nBu) with potassium hydroxide in methanol. All the complexes were characterized by elemental analysis, Fourier transform infrared and nuclear magnetic resonance (1H, 13C, 119Sn) spectroscopies, X-ray crystallography and thermogravimetric analyses. The crystal structures show that 1 has 2D network structure in which 2,2′-thiodiglycolic acid acts as a tetradentate ligand coordinating to the trimethyltin(IV) ions. Complexes 2, 3, and 4 are 3D metal-organic framework structures in which the deprotoned acids act as a tetradentate ligand afforded by four oxygen atoms.  相似文献   

20.
The crystal structure of the compound [Cu3(μ-ox)3(μ-4,4-bpy)2(4,4-bpy)2]n 1 (ox=oxalato, 4,4-bpy=4,4-bipyridine) is comprised of two-dimensional sheets in which copper(II)–oxalato chains are cross-linked by bridging bidentate 4,4-bpy ligands. Metal centers show a tetragonally elongated octahedral environment formed by four oxygen atoms from two asymmetrically coordinated oxalato ligands and two nitrogen atoms from two trans-coordinated 4,4-bpy molecules. The magnetic measurements show the occurrence of weak ferromagnetic couplings.  相似文献   

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