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1.
Three kinds of dithienothiophene/carbazole‐based conjugated polymers ( P1–P3 ), which bear acid‐protected and benzoic acid pendants in P2 and P3 , respectively, were synthesized via Suzuki coupling reaction. Interestingly, P1 – P3 exhibited reversible electrochromism during the oxidation processes of cyclic voltammogram studies, and P3 (with H‐bonds) revealed the best electrochromic property with the most noticeable color change. According to powder X‐ray diffraction (XRD) analysis, these polymers exhibited obvious diffraction features indicating bilayered packings between polymer backbones and π‐π stacking between layers in the solid state. Compared with the XRD data of P2 (without H‐bands), H‐bonds of P3 induced a higher crystallinity in the small‐angle region (corresponding to a higher ordered bilayered packings between polymer backbones), but with a similar crystallinity in the wide angle region indicating a comparable π‐π stacking distance between layers. Moreover, based on the preliminary photovoltaic properties of PSC devices ( P1 – P3 blended individually with PCBM acceptor in the weight ratio of 1:1), P3 (with H‐bonds) possessed the highest power conversion efficiency of 0.61% (with Jsc = 2.26 mA/cm2, FF = 29.8%, and Voc = 0.9 V). In contrast to P2 (without H‐bands), the thermal stability, crystallinity, and electrochromic along with photovoltaic properties of P3 were generally enhanced due to its H‐bonded effects. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012  相似文献   

2.
In order to improve the selectivity and the stability and the stability for gas permeation of poly (1-trimethylsilyl-1-propyne) (PTMSP) membrane, it was chemically modified by grafting polydimethylsiloxane (PDMS) chains. The graft copolymers were synthesized by four different methods via metallation of PTMSP with n-butyllithium. PDMS content of the graft co-polymers was controlled in the range of 4–92 mol %. Very tough, thin membranes could be prepared from these graft copolymers using a solvent casting method. Thermal property and gas permeability of the copolymer membranes thus obtained were evaluated. These membranes were relatively thermally stable, and the softening points were over about 150°C. Oxygen permeability coefficients Po2 and selectivity Po2/PN2 of PTMSP/PDMS graft copolymers depended on the PDMS content, the former was in the range of 1 X 10?8 to 2 × 10?7 cm3 (STP)· cm/(cm2· s · cm. Hg) and the latter was 2.0–3.1. Minimum values of PO2 and PN2 occured at PDMS content of about 55 mol %. The introduction of more than 60 mol % of PDMS resulted in oxygen permeability coefficient which was maintained for more than one moth (PO2 = 2 ? 6 × 10 ?8 cm 3 (STP)· cm/(cm2·s·cm Hg), PO2/PN2 = 2.3–2.7).  相似文献   

3.
Summary: In this work the first samples of polymeric semiconductors of a new structure are produced. Their electric conductivity is of the order ∼10−2 Ohm−1 · cm−1 and it increases with temperature. Their synthesis includes a stage of radiation grafting of a matrix‐type on stretched polyamide films. Conducting molecular circuits in such materials include fragments with conjugated bonds and metal clusters. The alternation of these fragments is determined by the polyamide matrix.

Plot of voltage versus current determined for new polymer semiconducting films where fragments with conjugated bonds alternate with silver clusters.  相似文献   


4.
A series of random terpolymers P2-P5 were designed and synthesized by randomly embedding 5 mol%, 10 mol%, 15 mol%and 25 mol% feed ratios of low cost 2,2-bithiophene as the third monomer to the famous donor-acceptor(D-A) type copolymer PTB7-Th(P1). All polymers showed similar molecular weight with number-average molecular weight(Mn) and weight-average molecular weight(Mw) in the range of(59-74) and(93-114) kg·mol~(-1), respectively, to ensure a fair comparison on the structure-property relationships.Compared with the control copolymer PTB7-Th, the random terpolymers exhibited enhanced absorption intensity in a wide range from400 nm to 650 nm in both solution and film as well as in polymer/PC71 BM blends. From grazing incident wide-angle X-ray diffraction(GIWAXS), compared with the regularly alternated copolymer PTB7-Th, the random terpolymers demonstrated mild structural disorder with reduced(100) lamellar stacking and slightly weakened(010) π-π stacking for the polymers as well as slightly reduced PC71 BM aggregation in polymer/PC71 BM blends. However, the measured hole mobility for terpolymers((1.20-3.73) × 104-cm2·V-1·s~(-1)) was evaluated to be comparable or even higher than 1.35 × 10~(-4) cm~2·V~(-1)·s-1 of the alternative copolymer. Enhanced average power conversion efficiency(PCE) from 7.35% to 8.11% and 7.79% to 8.37% was observed in both conventional and inverted device architectures from copolymer P1 to terpolymers P4, while further increasing the 2,2-bithiophene feed ratio decreased the PCE.  相似文献   

5.
Chlorine was determined in selenium by irradiation of 2-g samples for 37 min at a flux of 8·1010 n/cm2/sec. Chlorine was volatilised from hot concentrated nitric acid and precipitated as silver chloride. The isotope 38Cl (T12=37.3 min) was counted by γ-spectrometry. Sulfur and phosphorus were determined by irradiating 50-mg samples with and without cadmium shielding for 4 days at a thermal flux of 6·1012 n/cm2/sec and a fast flux of 4·1011 n/cm2/sec. The matrix activities were separated by distillation from sulfuric acid-hydrobromic acid at 200–220°. The isotope 32P (T12=14.3 d) was then precipitated, together with phosphate carrier, as ammonium phosphomolybdate, and counted with a G.M. tube. Amounts of 0.4–1 p.p.m. chlorine, 65–520 p.p.b. phosphorus and 1.5–4.6 p.p.m. sulfur were found in high-purity selenium samples.  相似文献   

6.
The compound 1-(N-morpholiniomethyl)spirobi(3-oxo-2,5-dioxa-1-silacyclopentan)ate crystallizes from aqueous solution of γ-butyrolactone in the form of two crystal hydrate modifications: monoclinic (with D = 1.53 g/cm3, space group P 21/n) and triclinic (D = 1.45 g/cm3, space group P1-). For the monoclinic form, an X-ray structural study at -100°C has been performed. For both structures the coordination polyhedron of the silicon atom is a trigonal bipyramid. In the crystal structures there are strong intermolecular hydrogen bonds of NH···O and OH···O types.  相似文献   

7.
Fully cyclized polyimides based on octadecyl- or hexadecyl 3,5-diaminobenzoate and 4,4′-(hexafluoroisopropylidene)diphthalic anhydride or 4,4′-oxydiphthalic anhydride were synthesized and deposited by the Langmuir-Schaefer technique onto a poly(1-trimethylsilylprop-1-yne) support. Composite membranes thus prepared show selective gas permeation for N2, O2, CO2, H2 with permeation rates in the range of 10−5 to 10−7 cm3 (STP)/(cm2 · s · cmHg).  相似文献   

8.
A novel coordination polymer {[Mn(azpy)(NCS)2(MeOH)2] · azpy}n( 1 ) (azpy = 4, 4'‐azopyridine), has been synthesized and characterized by X‐ray diffraction. It consists of a quasi two‐dimensional network structure constructed from 1‐D chains of [Mn(azpy)(NCS)2(MeOH)2]n connected by hydrogen bonds, which creates about 13.6 Å × 17.1 Å of channels. The coordination sphere of the manganese(II) ion is a distorted octahedron. The determination of the variable temperature magnetic susceptibilities (5—300 K) shows the existence of a very weak antiferromagnetic interaction with a J value of —0.03 cm—1.  相似文献   

9.
Magnetic polymer microspheres have been considered as a kind of new biopolymer materials with great advantages in bioseparation engineering and biomedicine engineering because they have not only polymer functional groups but also magnetic characteristics. Styrene-acrylic acid copolymer (p(S-AA)) magnetic microspheres were synthesized by dispersion polymerization with Fe3O4 as core and p(S-AA) as shell. The microspheres were characterized by SEM, size analysis, molecular weight and solid content measurement. All of them indicate that the microspheres are small in size, narrow in distribution, stable in chemistry and rich in functional groups on their surface. __________ Translated from Journal of Beijing Union University (Natural Science) 2008, 21(3): 82–84  相似文献   

10.
Summary. With a new kind of barrier coating material, namely inorganic–organic polymers, it is possible to obtain excellent barrier properties against oxygen, water vapor, and flavor permeation. These hybrid polymers can be synthesized by the sol–gel technique. If extremely low permeation values are needed, the combination of hybrid polymer coatings with thin inorganic oxidic layers (SiOx, AlOx) is very effective and leads to permeation values for oxygen and water vapor below 10−3 cm3/m2 · d · bar or g/m2 · d. These passive barrier layers can be further improved by the combination with active oxygen barrier layers which have been developed for the food packaging industry. This approach makes these multilayer laminates promising candidates for special applications in the food packaging industry as well as for sophisticated applications in technical areas: the encapsulation of sensitive organic devices like solar cells, organic light emitting diodes, or polymer electronic systems.  相似文献   

11.
The first coordination compound of 1,4‐dihydro‐2,3‐quinoxalinedione in ketoamine tautomeric form (denoted as H2qdione) was reported. H2qdione was obtained by a solid‐state reaction of o‐phenylenediamine and oxalic acid. Reaction of this ligand with CdCl2 solvothermally yielded a coordination polymer [Cd(H2qdione)Cl2]n, which was structurally characterized by X‐ray diffraction and IR spectroscopy. Continuous Cd2Cl2 diamonds form a double‐sided comb with terminal H2qdione‐κ2O,O′ as the comb teeth. Interaction of these combs through very extensive π–π stacking, C–H ··· Cl, and N–H ··· Cl hydrogen bonds leads to a novel 3D architecture and significant enhancement of solid‐state luminescence of about 10 times compared to the free H2qdione ligand.  相似文献   

12.
A new lanthanide-organic coordination polymer incorporating both substituted imdazole dicarboxylate and formate auxiliary ligand, namely {[Yb3(HEimda)42-HCOO) · 4H2O] · 2H2O} n (I) (H3Eimda = 1H-2-ethyl-4,5-imidazole-dicarboxylic acid), has been prepared and was structurally characterized by elemental analysis, IR and X-ray diffraction. It crystallizes in the monoclinic system, space group of C2/c. The polymer I is built from two dimensional (2D) double decker networks based on the Ln4HEimda4 tetranuclear basic carboxylate as secondary building unit. The extensive hydrogen bonds extend the 2D lamellar network into a 3D supramolecular aggregate. The emission spectrum of polymer I exhibits ligand-to-metal charge-transfer luminescence. Variable-temperature magnetic susceptibility measurement reveals that the end to end bridging fashion of formate group results in the depopulation of the stark levels for a single Yb3+ ion and/or possible antiferromagntic interactions between Yb3+ ions within the carboxylato bridged dinuclear unit.  相似文献   

13.
The films of poly[(R)-3-hydroxybutyric acid-co-10mol% 6-hydroxy-hexanoic acid] (P[(R)-3HB-co-6HH]) were prepared by melt-crystallized method at various crystallization temperatures. The morphologies and properties of melt-crystallized films were characterized by means of x-ray diffraction, differential scanning calorimetry, optical microscopy, and scanning electron microscopy. All of the melt-crystallized films showed the banded spherulite morphology. The enzymatic degradation of melt-crystallized films was carried out at 37 °C in an aqueous solution (pH 7.4) of PHB depolymerase from Alcaligenes faecalis. The rate of enzymatic erosion was strongly dependent on the crystallinity of films, and the highest rate was as large as 2.15 mg·h−1·cm−2. After enzymatic degradation, the banded morphology of P[(R)-3HB-co-6HH] spherulites was visible, suggesting that PHB depolymerase predominantly hydrolyzes polymer chains on the edges of crystalline lamellar stacks.  相似文献   

14.
Novel nonlinear optical (NLO) chromophore, 2-{3-[2-(4-methylsulfonylphenyl)vinyl]carbazol-9-yl}ethanol was synthesized and subsequently reacted with methacryloyl chloride to give a photoconducting NLO monomer ( M1 ). 2-Methylacrylic acid 2-[3-(diphenylhydrazonomethyl)carbazol-9-yl]ethyl ester ( M2 ) was also synthesized as a comonomer to enhance the carrier mobility of the NLO polymer. Photoconducting NLO polymers, P1 and P2 were obtained by the copolymerization of Ml with methyl methacrylate and M2 , respectively. These polymers were well soluble in organic solvents and showed glass transition at 177 °C and 196 °C, respectively. Polymer films of P1 and P2 were optically clear, and were transparent at wavelengths longer than 420 nm. The electro-optic coefficient (r33) of poled P1 films was measured to be ∼5 pm/V at 632.8 nm. The photoconductive sensitivities of P1 and P2 were 6.2 × 10−14 S·cm−1/mW·cm−2 and 5.6 × 10−11 S·cm−1/mW·cm−2.  相似文献   

15.
We have developed a space‐restricted wave function (SRW) method for the analysis of various types of intramolecular interactions. In this study, we demonstrate the applicability of our SRW method to the analysis of the nature of the P? O bond in phosphine oxide (R3PO), one of the hypervalent molecules. An interesting character of this bond has been extensively studied by focusing on the negative hyperconjugation of the O lone pair (nO) with the R3P group. We reinvestigated the nature of the bond in terms of a change in total energy to produce evidence for the validity of our method. The electronic states without the interaction involving three nO orbitals (R3P+?O?) produced by the method were used as reference states in the assessment of the effects of this nO–R3P interaction. The result confirms that this interaction plays an essential role in the nature of the bond and occurs between the nO orbitals and the P? R antibonding orbitals, in agreement with previous studies. A molecular orbital (MO)‐pair analysis technique shows that the nO–R3P interaction is decomposed into the negative hyperconjugation and the Pauli repulsion. Considering a reference state where the P? O bond is completely broken (R3P2+···O2?) at an interacting distance, P? O bond formation is attributed to one σ bond plus two 0.5 π bonds. This is equivalent to three banana bonds highly polarized to the O atom. Consequently, the SRW method suggested improved explanations of the nature of the P? O bond. © 2012 Wiley Periodicals, Inc.  相似文献   

16.
A mononuclear complex [Cu(HL · S)2(NO3)2] ( 1 ) and a one‐ dimensional coordination polymer [Cu(HL · S)Cl2]n ( 2 ) [HL · S = 4‐(pyridin‐2‐ylmethyl)tetrahydro‐2H‐thiopyran‐4‐ol] showcase the structure‐directing role of the counterions in their formation reaction: monodentate ligation of NO3 and Cl induces an octahedral (with two HL · S per Cu in 1 ) or trigonal‐bipyramidal (with one HL · S per Cu in 2 ) CuII coordination environment. In contrast to 1 exhibiting no coordinative metal–sulfur bonds in the crystal lattice (space group P21/c), 2 (P21/c) features intermolecular Cu–S contacts of 2.3188(7) Å. The coordination compounds are thermally stable up to ca. 160 °C. Whereas 1 demonstrates the spin‐like behavior of an isolated central CuII ion, compound 2 exhibits weak antiferromagnetic intra‐chain coupling with J ≈ –2.1 cm–1 between neighboring CuII ions.  相似文献   

17.
The title coordination polymer, {[Ag(C8H7O5)]·H2O}n, is built from Ag+ cations and singly protonated dehydronorcantharidin (SP‐DNC) anions, with a distorted trigonal‐planar geometry at the metal centre. The coordination number of AgI is three (with one Ag—π bond and two Ag—O bonds, one from each of three different SP‐DNC ligands), if only formal Ag–ligand bonds are considered, but can be regarded as five if longer weak Ag...O interactions are also included. The two‐dimensional corrugated‐sheet coordination polymer forms a non‐interpenetrating framework with (4.82) topology. Disordered water molecules are sandwiched between the sheets.  相似文献   

18.
A novel comb-like copolymer poly (1e)-graft-poly (ε-caprolactone) (SMA-g-PCL, SP), which can be used as an effective CaCO3 dispersant in organic solvent, was prepared via the esterification reaction between SMA and PCL. The structures and compositions of the graft copolymer were determined by Fourier transform infrared spectrometry (FTIR), H-nuclear magnetic resonance (1H NMR), and gel permeation chromatography (GPC), respectively. The influences of free comb-like copolymer on CaCO3 suspension viscosity and rheological behavior were investigated. It was found that the particle-binding bridge generated among CaCO3 particles through hydrogen bonding and/or electrostatic interactions increased the suspension viscosity as well as the depletion flocculation. On the other hand, it was noteworthy that the free comb-like copolymer could make the CaCO3 suspension evolve from shear-thinning fluid or nearly Newtonian fluid into shear-thickening fluid. It was attributed to the formation of a transient network through intermolecular associations between the adsorbed SP and the free polymer chains under the action of shear. Finally, the fitting parameters from the Herschel–Bulkley model were in good agreement with the evolution of the rheological behavior of CaCO3 suspension.  相似文献   

19.
L-aspartic acid zinc was synthesized by a rapid and convenient method in high yield under microwave conditions, and its single crystal structure was analyzed by X-ray diffraction. The structure unit of the title compound is [Zn(L-Asp)(H2O)2]·H2O, which is a bicyclo-complex forming a spiral linear polymer via coordination bonds. The spiral linear polymers are assembled as a three-dimensional supramolecule by intermolecular hydrogen bonds. The crystal belongs to the orthorhombic crystal system, P2(1)2(1)2(1) space group, a=0.7830(3) nm, b=0.9369(4) nm, c=11.599(5) nm, α=β=γ=90.00°, V=0.8509(6) nm3, Z=4, Dc=1.955 g/cm3, F(000)=512, μ=2.289. The toxicity of the title compound is lower than that of glutamic acid zinc and zinc sulfate.  相似文献   

20.
Low Temperature Investigation of Hydrogen Bridge Bonds in Lithium Tetrahydroxoborate by Raman Spectroscopy, X‐Ray and Neutron Diffraction (Li11B(OD)4) Low temperature Raman spectroscopic measurements on isotopically diluted Li11B(OH)4 with 8 % D and Li11B(OD)4 with 8 % H reveal four crystallographically different hydrogen bridge bonds. With decreasing temperatures beginning at ~50 K measured down to ~10 K the stretching modes of the hydroxide ions shift to higher wave numbers. For the strongest bond O–D···O the frequency shift is 16 cm?1and for the weakest 7 cm?1. For O–H···O the maximum in the frequency shift is 22 cm?1. X‐ray single crystal (LiB(OH)4) and neutron powder diffraction (Li11B(OD)4) data result in bond lengths for the four hydroxide ions in the range of 0.943 (3) Å ≤ d(O–D) ≤ 0.974 (3) Å. The value of the effect of inversion of the stretching mode frequencies seems to correlate with the strength of the hydrogen bridge bonds and is found to be different for the two isotopes H and D in this compound.  相似文献   

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