共查询到20条相似文献,搜索用时 15 毫秒
1.
《European Polymer Journal》1986,22(7):565-567
Polycondensations of 1,2- and 1,4-naphthoquinones with hydrazine hydrate and disulphinylhydrazine under various conditions were carried out. The optimum parameters for the disulphinylhydrazine synthesis were established. The thermal stabilities and electrical conductivities of the polynaphthoquinoneazines were determined. 相似文献
2.
Alexandre Boulay Sophie Laine Nadine Leygue Eric Benoist Sophie Laurent Luce Vander Elst Robert N. Muller Béatrice Mestre-Voegtle Claude Picard 《Tetrahedron letters》2013
In the design of dual-imaging probes, the first functionalized and neutral heterobimetallic Re(I)–Gd(III) complex, highly soluble in aqueous solutions, has been prepared. This system exhibits interesting photophysical properties (λem = 578 nm, ? = 1.4%) for optical imaging and substantial higher relaxivity (r1 = 6.6 mM−1 s−1 at 0.47 T and 37 °C) than the clinically used MRI contrast agents. Moreover, this system incorporates an aromatic ester functionality suitable for bioconjugation. 相似文献
3.
A new dicarboxylic acid monomer containing the N-methylcarbazole and imide structures, 3,6-bis(trimellitimido)-N-methylcarbazole (I), was prepared from the condensation of 3,6-diamino-N-methylcarbazole (c) and trimellitic anhydride. The diamine c was synthesized in three steps starting from the methylation of carbazole, followed by nitration and catalytic hydrazine
reduction. A series of N-methylcarbazole-containing poly(amide–imide)s were synthesized by direct polycondensation from the diimide–diacid I with various aromatic diamines. These poly(amide–imide)s had inherent viscosities of 0.66–1.47 dl/g and were readily soluble
in a variety of organic solvents, including N-methyl-2-pyrrolidone and N,N-dimethylacetamide (DMAc). Transparent, flexible, and tough films of these polymers could be cast from DMAc solutions, and
these films exhibited excellent mechanical strength. The glass-transition temperatures of these poly(amide–imide)s were in
the range 317–362 °C. All the poly (amide–imide) did not degrade noticeably below 480 °C in nitrogen, and the 10% weight loss
temperatures and char yields at 800 °C were above 520 °C and 60% in nitrogen, respectively, indicating high thermal stability.
Received: 8 February 2000/Accepted: 23 March 2000 相似文献
4.
A series of oxovanadium(IV) complexes: TpVO(pzH)(2,4-Cl–C6H3–OCH2COO) (1), TpVO(pzH)(C6H5–OCH2COO) (2), TpVO(pzH)(p-Cl–C6H4–COO) (3), TpVO(pzH)(3,5-NO2–C6H3–COO) (4), Tp∗VO(pzH∗)(p-Cl–C6H4–COO) (5) and Tp∗VO(pzH∗)(p-Cl–C6H4–COO) · CH3OH (6) (Tp = hydrotris(pyrazolyl)borate, pzH = pyrazole, Tp∗ = hydrotris(3,5-dimethylpyrazolyl)borate, pzH∗ = 3,5-dimethylpyrazole) were synthesized and their crystal structures were determined by X-ray diffraction. In all the complexes, the vanadium ions are in a distorted-octahedral environment with a N4O2 donor set. Hydrogen bonding interaction exists in each complex. Complexes 1 and 2 are hydrogen-bonded dimers. Dimeric units of 2 are connected to one another via weak inter-molecular C–H···O interactions to form a 2D network on the bc-face. In 3–6 there exist intramolecular N–H···O hydrogen bonds between the neutral pyrazole/3,5-dimethylpyrazole and the uncoordinated carboxyl oxygen atom. In addition, the catalytic activity of complex 2 in a bromination reaction in phosphate buffer with phenol red as a trap was evaluated by UV–Vis spectroscopy. Furthermore, the elemental analyses, IR spectra and thermal stabilities were recorded. 相似文献
5.
By employing trans-dicyano or pentacyanometalate as building block and using a bicompartimental Schiffbase based manganese(III) compound as assemble segment, two new cyanide-bridged heterometallic Fe(III)–Mn(III) complexes {[Mn(L)(H2O)][Febpb(CN)2]}·2CH3OH (1) and {[Mn(L)(H2O)]2··[Fe(CN)5NO]} (2) (bpb2– = 1,2-bis(pyridine-2-carboxamido)benzenate, L = N,N'-ethylene-bis(3-ethoxysalicylideneiminate) have been synthesized and characterized by elemental analysis, IR spectroscopy and X-ray structure determination. Single X-ray diffraction analysis reveals binuclear FeMn and trinuclear FeMn2 structure, respectively, in which the cyanide precursor acts as mono- or bidentate ligand to connect the Mn(III) Schiff-base unit(s). Furthermore, these two complexes are self-complementary through coordinated aqua ligands from one complex and the free O4 compartments from the neighboring complex, giving dimeric and 1D single chain supramolecular structure. Investigation of the magnetic susceptibility of 1 reveals weak antiferromagnetic coupling between the adjacent Mn(III) ions. Based on the binuclear FeMn model, best fit of the magnetic susceptibilities of 1 leads to the magnetic coupling constants J =–1.37 cm–1 and zJ′ =–0.72 cm–1 (1). 相似文献
6.
7.
《Journal of Coordination Chemistry》2012,65(6):1097-1109
In this work, we describe the syntheses, characterization, and antifungal activity of [In{S2CNR(R1)}3] (1), [Ga{S2CNR(R1)}3] (2), [Bi{S2CNR(R1)}3] (3), [In{S2CNR(R2)}3] (4), [Ga{S2CNR(R2)}3] (5), and [Bi{S2CNR(R2)}3] (6) {R?=?Me; R1?=?CH2CH(OMe)2; and R2?=?2-methyl-1,3-dioxolane}. All complexes have been characterized using infrared and 1H and 13C spectroscopy, and the structures of 1, 3, 4, and 6 have been authenticated by X-ray diffraction. The In(III)–dithiocarbamate bonding scheme depicts a distorted octahedral with asymmetric In(III)–S bonds and S–In–S angles. A pentagonal bipyramid is observed for the corresponding Bi(III) complexes with intermolecular Bi–S associations through the lone pair of electrons. The antifungal activities of 1–6 have been screened against Aspergillus niger, Aspergillus parasiticus, and Penicillium citrinum, and the results have been compared with those of nystatin and miconazole nitrate, as control drugs. 相似文献
8.
Agnieszka Czylkowska Danuta Czakis-Sulikowska Rafał Kruszyński Mirosława Markiewicz 《Structural chemistry》2010,21(2):415-423
A novel mixed-ligand complexes of Er(III), Yb(III) and Lu(III) with title ligands were prepared and characterized by chemical
and elemental analysis and IR spectroscopy, conductivity (in methanol, dimethyloformamide and dimethylsulphoxide). The thermal
properties of complexes in the solid state were studied. The mode of metal–ligand coordination was discussed. The title compounds
are isomorphic and isostructural in solid state. All atoms in studied compounds lie in general positions but occurrence of
inversion on the midpoint of the bond linking two pyridine rings leads to existence in asymmetric unit one complex molecule
and half of outer coordination sphere 4-bpy molecule. All chelating carboxylate groups are symmetrically bonded to the metal
cations. The molecules of studied compounds are connected to the three dimensional network via O–H···O and O–H···N intermolecular
hydrogen bonds. In the structures also exist C–H···O, C–H···Cl weak hydrogen bonds and π····π stacking interactions. 相似文献
9.
E. A. Chalaya A. G. Tyurin M. V. Vasekha A. I. Biryukov 《Russian Journal of General Chemistry》2016,86(7):1545-1551
Pourbaix diagrams of Cu–H2SO4–H2O and Ni–H2SO4–H2O systems have been refined, and stability regions of the sulfite phases have been determined. State diagrams of double copper(I)–copper(II) and copper(I)–nickel(II) sulfites have been constructed. Double copper(I)–nickel(II) sulfite has been isolated from aqueous solutions saturated with sulfur dioxide. The solutions at different ratios of the metals have been studied by spectrophotometry; the isolated double sulfite has been studied by X-ray diffraction, IR spectroscopy, dispersion analysis, and thermal analysis. Fundamentals of thermodynamic prognostication of the Cu2SO3·MSO3 double sulfites synthesis have been elaborated. 相似文献
10.
Qiang Wei Lin Shi Hui Cao Huai Yang Yan Bin Wang 《中国化学快报》2007,18(5):527-529
A series of symmetrical azine-type liquid crystals were synthesized. The characteristic of these liquid crystals is that they had high clearing point ( ~320 ℃) and broad thermal range of nematic phase ( ~154 ℃). It was also found that the end groups of the liquid crystals had effect on the mesomorphic properties. 相似文献
11.
Guo Lin ZHANG Ze Hua LIU Hai Qing GUO* State Key Laboratory of Rare Earth Materials Chemistry Applications College of Chemistry Molecular Engineering Peking University Beijing 《中国化学快报》2004,15(11)
Much attention has been paid to the phosphorescent materials in recent years for their potential application as highly efficient electroluminescent (EL) emitters in organic light emitting diodes (OLEDs) 1-2. Heavy metal complexes, particularly those containing Pt and Ir, where strong spin orbit coupling leads to singlet-triplet state mixing, can result in high efficiency electrophosphorescence in OLED 3-5. Among the many kinds of metal complexes, iridium complexes are the most effective … 相似文献
12.
A donor-acceptor dyad containing perylenediimide as the electron acceptor and π-extended tetrathiafulvalene as electron donor has been successfully synthesized by means of a Wittig reaction. Cyclic voltammetry and absorption spectroscopy show that both electroactive units preserve their nature, whereas preliminar photophysical investigations show a strong fluorescence quenching. 相似文献
13.
Chunming Lin Yanhua Song Fei Gao Hongguang Zhang Ye Sheng Keyan Zheng Zhan Shi Xuechun Xu Haifeng Zou 《Journal of Sol-Gel Science and Technology》2014,69(3):536-543
Uniform Eu3+-doped SiO2 nanorods were synthesized through a simple sol–gel method using cetyltrimethylammonium bromide (CTAB) as surfactant template and tetraethylorthosilicate as silicon source. X-ray diffraction, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectrum, scanning electron microscope (SEM), transmission electron microscopy, and photoluminescence spectra were employed to characterize the products in detail. The nanorods have good uniformity and their diameters and lengths are in the range of 200–300 and 500–700 nm through the SEM images, respectively. The formation of the nanorods was studied by taking SEM images after different aging time. The experimental results indicate that CTAB plays a crucial role in the formation of the silica nanorods. The luminescence of Eu3+-doped SiO2 nanorods is dominated by red-emission around 612 nm due to intra-atomic 4f → 4f (5D0 → 7F2) transition of Eu3+ ions. Furthermore, the effect of doping concentrations of Eu3+ ions on the luminescence was investigated. 相似文献
14.
Journal of Thermal Analysis and Calorimetry - New complexes with formulae: Ln(4-bpy)(CBr2HCOO)3·3H2O (where Ln(III) = Gd, Tb, Dy) and Er(4-bpy)1.5(CBr2HCOO)3·3H2O, were... 相似文献
15.
Olga Botezat Irina G. Filippova Jürg Hauser Karl Krämer Silvio Decurtins Shi-Xia Liu 《Journal of Coordination Chemistry》2016,69(1):72-80
A new μ3-oxo trinuclear chromium(III) propionate cluster, [Cr3(μ3-O)(O2CCH2CH3)6(pyr)3]NO3·0.25(H2O) (1), has been synthesized by reaction of a μ3-oxo trinuclear chromium(III) propionate precursor [Cr3(μ3-O)(O2CCH2CH3)6(H2O)3]NO3 with a pyrazol ligand (pyr) and characterized by IR spectroscopy, single-crystal X-ray structure determination, and thermal analysis. Magnetic susceptibility and magnetization studies revealed antiferromagnetic exchange interactions within the trinuclear Cr(III) cluster (J = ?11.9 cm?1) and determined the electronic ground state (S = ½) of the compound. 相似文献
16.
M. D. Revenko P. N. Bourosh O. V. Palamarchuk J. Lipkowski M. Gdaniec Yu. A. Simonov 《Russian Journal of Inorganic Chemistry》2009,54(10):1581-1589
Condensation of 5-bromosalicylaldehyde with Girard’s reagent T yields a new ligand in the form of a salt, 5-bromosalicylaldehyde (carboxymethyl)trimethylammonium chloride hydrazone (5-BrH2SalGT)Cl (I). Ligand I is readily soluble in water and reacts with iron chloride to give the complex [Fe(5-BrSalGT)Cl2] (II). Treatment of II with KCNS leads to the compound [Fe(5-BrSalGT)(NCS)2(H2O)] (III). At any ratio of the initial reagents, only complexes with the ratio metal: ligand = 1: 1 are isolated. Comparison of the structural data for compounds I–III shows that ligand I is deprotonated in the course of complex formation and is coordinated in the anionic form. Its conformational rearrangement is minimal and involves only a change in the orientation of the terminal group N(CH3)3. In complexes II and III, ligand I is coordinated to the metal ion through the ONO donor atoms. The structures of the complexes with different acido ligands are significantly different. Although the complexes contain each two inorganic anions, their coordination polyhedra differ from each other. In II, the iron atom is at the center of a trigonal bipyramid, whereas in III the iron atom has a tetragonal-bipyramidal environment due to the extra coordination of a water molecule. In both complexes, the iron atom is in the high-spin state: at room temperature, μeff is 5.86 and 5.81 μB for II and III, respectively. Complexes II and III are ordinary paramagnets down to 2 K. 相似文献
17.
18.
The reaction of α-benzoinoxime, H2BNO with FeCl3 in the presence of Et3N as a base gives the mononuclear Fe(III) complex, Fe(HBNO)3 (1). Treatment of 1 with a methanolic solution of KOH at room temperature leads to a dinuclear Fe(III)–Fe(III) complex, [Fe(HBNO)2OH]2 (2). The complexes were initially characterized on the basis of their elemental, mass and thermal analyses. The IR studies were useful in assigning the coordination mode of the benzoinoxime ligand to the iron metal. In addition, the presence of a hydroxo-bridge in the dimeric complex 2 is inferred from the IR spectral studies. Room-temperature Mössbauer studies indicated octahedral, high-spin iron(III). Variable-temperature magnetic susceptibility measurements supported the existence of the μ-dihydroxo-bridging structure core, FeIII(μ-OH)2FeIII in the dinuclear complex 2. Theoretical modelling of the magnetic data indicated a weak antiferromagnetic spin exchange between the iron(III) centers (J = −8.35 cm−1, g = 2.01, ρ = 0.02 and TIP = 1.7 × 10−4 cm3 mol−1 for H = −2JS1 · S2). The electronic spectra of the complexes revealed two bands due to d–d transitions and one band assignable to an oxygen (pπ) → Fe(dπ∗) LMCT transition observed in each complex. An additional charge-transfer transition, assignable to μ-hydroxo(pπ) → Fe(dπ∗), was observed for the dimeric complex 2. The structural and vibrational behaviors of these complexes have been elucidated with quantum mechanical methods. 相似文献
19.
20.
E. V. Antina G. B. Guseva A. E. Loginova A. S. Semeikin A. I. V’yugin 《Russian Journal of General Chemistry》2010,80(11):2374-2381
Bis(2,4,7,9-tetramethyl-8-ethyldipyrrolylmethen-3-yl)acetylene dihydrobromide (H2L·2HBr), new bis(dipyrrolylmethene), in whose molecule dipyrrolylmethene domains were connected through 3,3′-carbon atoms
of internal pyrrole nuclei by acetylene spacer, were synthesized by original procedure. The compound was characterized by
element analysis, IR, 1H NMR, and electronic spectroscopy. The comparative analysis of spectral properties shows the reduction of the basicity of
H2L ligand in comparison with the structural analogs, which contain internal methylene spacer. The quantum-chemical simulation
showed that the rigid acetylene spacer gives linear structure to the H2L molecule in contrast to the spiral-shaped geometry of structural analogs with -CH2- spacer. 相似文献