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1.
Several tetrathiafulvalene (TTF) and tetraselenafulvalene (TSF) salts of tetrahalogenozinc(II) and -cadmium(II) anions Dx [MX4] (D = TTF or TSF; M = Zn and Cd; X = Cl, Br, and I; x = 2.0-6.6) have been prepared by the reaction of [TTF]3[BF4]2 or [TSF]3[BF4]2 with [NEt4]2[MX4] in acetonitrile and by the electrolysis of TTF or TSF in acetonitrile containing [NEt4]2[MBr4]. Electrical resistivities of these salts measured for compressed pellets fall in the range 1 × (101–107) Ω cm at 25 °C; the value decreases with increasing bulkiness of the anions: [MCl4]2– > [MBr4]2− > [MI4]2−. Stackings and electronic states of TTF and TSF molecules are discussed on the basis of electronic reflectance, ESR, IR, and Raman spectra.  相似文献   

2.
The complexation between poly(ethylene oxide) (PEO) and poly(acrylic acid) (PAA) was made by using double the molar quantity of either polymer component at pH 2 where the resulting complex completely precipitates. After the removal of the precipitate, PEO or PAA remaining in the supernatant was subjected to gel permeation chromatography to investigate the change in the molecular weight distribution (MWD) caused by the complexation. No remarkable difference is observed in the MWD curves for PEO[1] (Mw=1.37 × 104) before and after the complexation with PAA[1] (Mw=1.10 × 103) and PAA[2] (Mw=4.16 × 105). However, the MWD curves of PEO[2] (Mw=1.26 × 105) and PAA[2] become shortened and shift to the low molecular weight side after the complexation with PAA[1] or [2] and PEO[2], respectively. This tendency is enhanced by increasing the complexation temperature. From these results, it is indicated that the complexation between PEO and PAA deals with an equilibrium reaction, and the equilibrium constant is dependent on the chain length of both polymer components and also on the complexation temperature.  相似文献   

3.
In this work; (a) complexation reaction of zirconium tetra-n-butylate, Zr(OBu n )4, with MAc and different organic acids. (b) the hydrolysis reaction of modified Zr species, and (c) the polymerization reaction of complex products are studied. Zr(OBu n )4 was reacted with different mole ratios of methacrylic acid (MAc) at room temperature and the maximum combination ratio was found to be 1∶2 [Zr(OBu n )4∶MAc] by FT IR. The modification of zirconium tetra-n-butylate with the acid mixtures [methacrylic acid-acetic acid (MeCOOH), methacrylic acid-propionic acid (EtCOOH), methacrylic acidbutyric acid (PrCOOH)] was made for a combination ratio of 1∶1∶1 [MAc∶RCOOH∶Zr(OBu n )4R∶Me. Et, Pr] and the products were characterized by1H-NMR, FT-IR, and UV-spectroscopies. Following their synthesis, hydrolysis of the complexes with various amounts of water and polymerization with benzoyl peroxide were realized. The hydrolysis and polymerization products of the complexes were studied by Karl-Fischer Coulometric titration and thermal analysis respectively. Methyl-ethyl-ketone (MEK) and chloroform were chosen as solvents.  相似文献   

4.
In this work, (a) complexation reaction of zirconium tetra-n-butylate, Zr(OBu n )4, with MAc and different organic acids, (b) the hydrolysis reaction of modified Zr species, and (c) the polymerization reaction of complex products are studied. Zr(OBu n )4 was reacted with different mole ratios of methacrylic acid (MAc) at room temperature and the maximum combination ratio was found to be 1:2 [Zr(OBu n )4:MAc] by FT-IR. The modification of zirconium tetra-n-butylate with the acid mixtures [methacrylic acid-acetic acid (MeCOOH), methacrylic acid-propionic acid (EtCOOH), methacrylic acid-butyric acid (PrCOOH)] was made for a combination ratio of 1:1:1 [MAc:RCOOH:Zr(OBu n )4; R: Me, Et, Pr] and the products were characterized by1H-NMR, FT-IR, and UV spectroscopies. Following their synthesis, hydrolysis of the complexes with various amounts of water and polymerization with benzoyl peroxide were realized. The hydrolysis and polymerization products of the complexes were studied by Karl-Fischer coulometric titration and thermal analysis, respectively. Methyl ethyl ketone(MEK) and chloroform were chosen as solvents.  相似文献   

5.
Three conjugated ethynylene-carbazole polymers with Tetrathiafulvalene (TTF) as pendant group (P1–P3) were synthesized by using sonogashira coupling reaction and characterized by 1H NMR, GPC, CV, UV–Vis, FL, and TGA. CV and UV–Vis spectra showed that an intramoleular interaction existed between the electron-rich moiety TTF and electron-deficient moiety polyethynylcarbazole of the polymers. A strong fluorescence quench (ca. 99%) could be observed, compared to the polyethynylene-carbazole without TTF units, which could be ascribed to the photo-induced electron transfer (PET) interaction from TTF moiety to the polyethynylene-carbazole backbone. The observed onset decomposition temperatures (T d) for P1–P3 varied from 256 to 298 °C. The polymers mentioned above exhibited good thermal properties and higher conductivity (neutral conductivity ~7–11 × 10−7 S cm−1; doped conductivity ~6–11 × 10−4 S cm−1).  相似文献   

6.
The electrochemical reduction of different cations formed by the solubilization of hexahydrated chromium salts in DMF was studied by polarography and cyclic voltammetry on stationary mercury dropping electrode, with tetrabutylammonium tetrafluoroborate 0.2 M as an indifferent electrolyte.The nature of the cations formed by water—DMF ligand exchange in the chromium complexation sphere depends on the nature of X(X = Cl, Br, ClO4).The reduction potentials and some electrochemicals kinetics parameters of [Cr(DMF)6]3+, [Cr(H2O)6]3+, [Cr(DMF)5Br]2+, [Cr(DMF)4Cl2]+ and [Cr(DMF)3Cl3] were determined as well as exchange reactions between these electroactive species which may be simultaneously present either in solution or at the electrode.  相似文献   

7.
The sorption properties towards dysprosium(III) ions of three samples of mesoporous silicas functionalized with phosphonic groups????Si(CH2)2P(O)(OH)2 were studied. It was found that for the sample synthesized by spray-drying using OTAB as a template both sorption and desorption rate of Dy3+ ions is high, due to the defined porosity of the sorbent. Sorption of Dy3+ ions by bridged silsesquioxane xerogels with disordered structure is significantly hindered by diffusion processes, due to the chaotic packing of globules. Using a model for the chemical reactions, the composition of dysprosium(III) complexes with surface phosphonic groups were determined, and their formation constants were calculated. It was shown that xerogels with higher surface concentration of ligand groups (L), can form complexes DyL3 and DyL4 ?. Meanwhile, the sample synthesized by spray-drying method forms only DyL2 + and DyL3 complexes. For this sample, complexes DyL3 are more stable than for xerogels. So, mesoporous silica derived by spray-drying method, with defined spatial porosity and relatively low surface concentration complexation groups, is characterized by the best sorption properties towards dysprosium(III) (adsorption and desorption kinetics, the value of the static sorption capacity).  相似文献   

8.
《分离科学与技术》2012,47(15):3321-3331
Abstract

Herein the removal and recovery of chromium anions from aqueous solutions by using nanofiltration pilot‐scale equipment (Osmonics Sepa CF Membrane Cell) with a water‐soluble amino calix[4]arene derivative was studied. To understand the selectivity, the authors also examined the retention of chromium anions in the presence of Cl?, NO3 ?, SO4 2?, HSO4 ?, CO3 2?, PO4 3?, H2PO4 ? anions in nanofiltration‐complexation. From the results water‐soluble amino calix[4]arene was effective and selective ligand for dichromate anions over nitrate anions, in a nanofiltration‐complexation system at pH 2.5. Moreover, the recovery and reusability studies of dichromate and nitrate anions and also ligand were performed.  相似文献   

9.
Wuu-Jyh Liang 《Polymer》2004,45(5):1617-1626
A new hybrid polymer electrolyte system based on chemical-covalently polyether and siloxane phases is designed and prepared in the presence of lithium perchlorate (LiClO4) which acted as both ionic source and the epoxide ring-opening catalyst. The effect of salt-doped level on the microstructure and ionic conductivity of these composite electrolytes were investigated by means of Fourier transform infra-red spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis, a.c. impedance and multinuclear solid-state nuclear magnetic resonance measurements. DSC results indicate that the formation of transient cross-links between Li+ ions and the ether oxygens on complexation with LiClO4 results in an increase in polyether segment Tg. However, the polyether segment Tg decreases at the highest salt concentration (5.0 mmol LiClO4/g PEGDE), ascribing to the plasticizing effect. The behavior of ion transport is coupled with the segmental motions of polymer chains and also correlated with the interactions between ions and polymer host.  相似文献   

10.
A novel tetrathiafulvalene (TTF) bearing a conjugated β-diketone moiety (TTFacacH) has been synthesized and fully characterized. The chelating ability of its enolate anion (TTFacac) has been investigated with [MII(OAc)2 · xH2O] (OAc = acetate and M = Zn, Cu and Ni) leading to complexes, where the metal center is coordinated by two TTFacac. Modulation of the redox properties of the TTF can be achieved through the simple change of the two apical ligands which completed the octahedral coordination geometry. This redox active ligand shows promising features for the elaboration of hybrid organic–inorganic building blocks.  相似文献   

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