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1.
Two new solid‐state uranium(IV) sulfate x‐hydrate complexes (where x is the total number of coordinated plus solvent waters), namely catena‐poly[[pentaaquauranium(IV)]‐di‐μ‐sulfato‐κ4O:O′] monohydrate], {[U(SO4)2(H2O)5]·H2O}n, and hexaaquabis(sulfato‐κ2O,O′)uranium(IV) dihydrate, [U(SO4)2(H2O)6]·2H2O, have been synthesized, structurally characterized by single‐crystal X‐ray diffraction and analyzed by vibrational (IR and Raman) spectroscopy. By comparing these structures with those of four other known uranium(IV) sulfate x‐hydrates, the effect of additional coordinated water molecules on their structures has been elucidated. As the number of coordinated water molecules increases, the sulfate bonds are displaced, thus changing the binding mode of the sulfate ligands to the uranium centre. As a result, uranium(IV) sulfate x‐hydrate changes from being fully crosslinked in three dimensions in the anhydrous compound, through sheet and chain linking in the tetra‐ and hexahydrates, to fully unlinked molecules in the octa‐ and nonahydrates. It can be concluded that coordinated waters play an important role in determining the structure and connectivity of UIV sulfate complexes.  相似文献   

2.
A nickel(II) coordination complex, bis[2,6‐bis(1H‐benzimidazol‐2‐yl‐κN3)pyridine‐κN]nickel(II) sulfate, [Ni(C19H13N5)2]SO4 or [Ni(H2L)2]SO4, having four peripheral tetrahedrally oriented N—H donor units, combines with sulfate bridges to create hydrogen‐bonded structures of varied dimensionality. The three crystal structures reported herein in the space groups P212121, I and Pccn are defined solely by strong charge‐assisted N—H…O hydrogen bonds and contain disordered guests (water and dimethylformamide) that vary in size, shape and degree of hydrophilicity. Two of the compounds are channelled solids with three‐dimensional structures, while the third is one‐dimensional in nature. In spite of their differences, all three present a striking resemblance to the previously reported anhydrous relative [Guo et al. (2011). Chin. J. Inorg. Chem. 27 , 1517–1520], which is considered as the reference framework from which all three title compounds are derived. The hydrogen‐bonded frameworks are described and compared using crystallographic and topological approaches.  相似文献   

3.
Single crystals of [Cu(ATSC)]NH2SO3 ( 1 ) (ATSC –4‐allylthiosemicarbazide) were obtained by electrochemical synthesis using alternating current. Compound ( 1 ) crystallizes in P212121 sp. gr., a = 6.8284(2), b = 9.3054(3), c = 16.1576(11) Å, Z = 4. ATSC moiety acts as tetradentate ligand, chelating two symmetrically related copper atoms. The Cu atom possesses trigonal pyramidal coordination, formed by two sulphur atoms (one of them at the apical position), nitrogen atom and C=C bond. Sulfamate anion is associated via hydrogen bonds. By slow hydrolysis of 1 crystals of [Cu2(ATSC)2]SO4 ( 2 ) were obtained: P 1 sp. gr., a = 9.526(2), b = 12.687(2), c = 14.7340(10) Å, α = 95.119(10), β = 89.903(12), γ = 109.113(14)°, Z = 4. The asymmetric unit of 2 contains two formula units, which are related by pseudosymmetry via a glide plane a. One half of four ATSC molecules act as in 1 , the rest as tridentate ligands, which coordinate the two copper atoms in apical positions with sulfate anions. This Cu–S coordination was to date unknown. The structure of the ATSC ligands contributes to the unexpected competitiveness of C=bond in the coordination sphere of CuI inspite of strong donor atoms.  相似文献   

4.
A spectrophotometric method is suggested for measuring concentration changes in near-electrode layers. The method is based on the interaction between a monochromatic light beam, traversing the electrochemical reaction zone, and metal ions. Concentration changes in the near-cathode layer during electrolysis of copper(II) in sulfate electrolytes and potassium dicyanoaurate in phosphoric electrolytes are studied.  相似文献   

5.
The crystal structures of three first‐row transition metal–pyridine–sulfate complexes, namely catena‐poly[[tetrakis(pyridine‐κN)nickel(II)]‐μ‐sulfato‐κ2O:O′], [Ni(SO4)(C5H5N)4]n, (1), di‐μ‐sulfato‐κ4O:O‐bis[tris(pyridine‐κN)copper(II)], [Cu2(SO4)2(C5H5N)6], (2), and catena‐poly[[tetrakis(pyridine‐κN)zinc(II)]‐μ‐sulfato‐κ2O:O′‐[bis(pyridine‐κN)zinc(II)]‐μ‐sulfato‐κ2O:O′], [Zn2(SO4)2(C5H5N)6]n, (3), are reported. Ni compound (1) displays a polymeric crystal structure, with infinite chains of NiII atoms adopting an octahedral N4O2 coordination environment that involves four pyridine ligands and two bridging sulfate ligands. Cu compound (2) features a dimeric molecular structure, with the CuII atoms possessing square‐pyramidal N3O2 coordination environments that contain three pyridine ligands and two bridging sulfate ligands. Zn compound (3) exhibits a polymeric crystal structure of infinite chains, with two alternating zinc coordination environments, i.e. octahedral N4O2 coordination involving four pyridine ligands and two bridging sulfate ligands, and tetrahedral N2O2 coordination containing two pyridine ligands and two bridging sulfate ligands. The observed coordination environments are consistent with those predicted by crystal field theory.  相似文献   

6.
Two new Pd(II) complexes of N′‐(4‐(diethylamino)‐2‐hydroxybenzylidene)furan‐2‐carbohydrazide were synthesized and characterized using various spectral methods. The structure of one of the complexes was determined using single‐crystal X‐ray diffraction. DNA and protein binding affinities of the synthesized compounds were examined using UV–visible and fluorescence titration method. In addition, the in vitro cytotoxicity of the compounds was evaluated against A549 (lung cancer) and MCF7 (breast cancer) cell lines using the MTT assay method.  相似文献   

7.
Excess one‐handed helical poly(2‐methoxyaniline) (PMOA) was synthesized by electrochemical polymerization of 2‐methyoxy aniline in the presence of CDS. PMOA prepared at strong acidic condition shared an opposite excess one‐handed helicity against to that prepared at weak acidic condition. Through studying helix‐inducing dynamic, mechanism for helical opposition was found originating from the dynamic transfer. While predominant dynamic transferred from electrostatic interaction to H‐bonding, PMOA selectively adsorbing the opposite excess one‐handed helix. Dynamic‐transferring tests were carried out by adjusting acid and salt concentration in reaction solution, respectively. Dedoping and redoping cycle was also performed in order to study the chiroptical properties of PMOA after dedoping. The electroactivity of PMOA was checked by cyclic voltammetry. At the same time, PMOA showed interesting chiroptical properties in the states of reduction and oxidation, respectively. ICD spectra indicated that helicity and handedness were well remained in PMOA backbone after redox cycle. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

8.
The role of hydrogen bonding in the chemistry of transition‐metal complexes remains a topic of intense scientific and technological interest. Poly(acrylo‐amidino diethylenediamine) was synthesized to study the effects of hydrogen bonding on complexes at different pHs. The polymer was synthesized through the coupling of diethylene triamine with polyacrylonitrile fiber in the presence of AlCl3 · 6H2O addition. The adsorption capacity of this polymer was 11.4 mequiv/g. The ions used for the adsorption test were CrO, PO, Cu2+, Ni2+, Fe2+, and Ag+. All experiments were confirmed with Fourier transform infrared. In the study of anion adsorption, at low pHs, only ionic bonds existed, whereas at high pHs, no bonds existed. However, in the middle pH region, both ionic bonds and hydrogen bonds formed between poly(acrylo‐amidino diethylenediamine) and the chromate ion or phosphate ion. When poly(acrylo‐amidino diethylenediamine) and metal ions (Cu2+, Ni2+, Fe2+, and Ag+) formed complexes, a hydrogen‐bonding effect was not observed with Fourier transform infrared. The quantity of metal ions adsorbed onto poly(acrylo‐amidino diethylenediamine) followed the order Ag+ > Cu2+ > Fe2+ > Ni2+. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2010–2018, 2004  相似文献   

9.
Acetylene‐linked reactive intermediates of (nitrenoethynyl)‐X‐methylenes, (nitrenoethynyl)‐X‐silylenes, and (nitrenoethynyl)‐X‐germylenes are almost experimentally unreachable (X–M–C≡C–N; X=H ( 1 ), CN ( 2 ), OH ( 3 ), NH2 ( 4 ), NO2 ( 5 ), and CHO ( 6 ); M=C, Si, and Ge). The effects of the electron‐donating and electron withdrawing groups were compared and contrasted at seven levels of theory. All singlet species as ground states with one local open‐shell singlet carbene subunit (π1π1) and another local open‐shell singlet nitrene subunit (π1π1) were found to be more stable than their corresponding triplets including one local open‐shell singlet carbene (δ1π1) (or one local closed‐shell singlet carbene [δ2π0]) and another local triplet nitrene subunit (π1π1) with 45.94–77.996 kcal/mol singlet–triplet energy gap (ΔEs‐t). Their relative silylenes and germylenes made reduction of ΔEs‐t, so the triplet ground states were found for species 3 Si , 4 Si , 5 Si , 2 Ge , 3 Ge , 4 Ge , and 5 Ge . All the singlet silylenes/germylenes formed by one local closed‐shell singlet silylenes/germylenes (δ2π0) and one local closed‐shell singlet nitrene subunit (π2π0). Also, one local closed‐shell singlet silylene/germylene subunit (δ2π0) and one local triplet nitrene subunit (π1π1) were observed for triplet silylenes/germylenes. The singlet and triplet species 3 Si , 4 Si , 3 Ge , and 4 Ge , due to their electrophilic (Si4/Ge4) and nucleophilic (X5) centers, could be identified as intermediates in chemical reactions.  相似文献   

10.
All 1H and 13C NMR signals of the four poly(phenylenephthalides): polydiphenylenephthalide ( P(DPh)‐1 ), polyterphenylenephthalide ( P(TPh)‐2 ) and two sequentially ordered polymers with different ratios of alternating diphenylenephthalide and terphenylenephthalide units ( P(DTPh)‐3, P(DDTPh)‐4 ) were assigned unequivocally with two‐dimensional NMR techniques (1H–1H COSY and NOESY; 1H–13C HSQC and HMBC). There are four types of polyphenylene fragments: not symmetrical end, symmetrical inner, symmetrical pre‐end and formally symmetric pre‐end. The equivalent carbon atoms in these fragments have different chemical shifts. A full additivity of the chemical shifts for the side phthalide and polyphenylene carbon atoms was revealed. A new structure of diads with a mirror symmetry plane, passing through the middle of aromatic moieties, is proposed. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

11.
9‐Dehydro‐17‐hydro‐andrographolide (DHA) and sodium 9‐dehydro‐17‐hydro‐andrographolide‐19‐yl sulfate (DHAS) are active ingredients of xiyanping injection in clinical use. A simple, rapid and sensitive UHPLC‐ESI‐MS/MS method was developed for the determination of DHA and DHAS in rat plasma, and the pharmacokinetics of DHA and DHAS after intravenous administration of xiyanping injection was investigated. The plasma samples were treated with methanol to precipitate out protein, and the separation of DHA and DHAS was achieved on a Waters BEH C18 column with a mobile phase consisting of acetonitrile and 10 mmol/L ammonium acetate solution at a flow rate of 0.4 mL/min. DHA, DHAS and the internal standard (internal standard, IS) diethylstilbestrol were detected at negative ion mode. The precursor‐product ion pairs used in multiple reaction monitoring mode were: m/z 349.1 → 286.9 (DHA), m/z 428.9 → 96.0 (DHAS) and m/z 267.1 → 236.9 (IS). Calibration curves offered satisfactory linearity within the test range, and all correlation coefficients were >0.995. The lower limit of detection of DHA and DHAS in plasma samples were determined to be 0.1 ng/mL. The lower limit of quantitation was 0.5 ng/mL for DHA and DHAS. All the recoveries of the quality control samples were in the range of 86.0–102.4%. The ratios of matrix effect were between 89.2 and 105.1%. The method was fully validated and successfully applied to the pharmacokinetic study of DHA and DHAS in rats. The study showed that both DHA and DHAS were distributed and eliminated rapidly in rats. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

12.
The era of poly(ethylene glycol) (PEG) brushes as a universal panacea for preventing non‐specific protein adsorption and providing lubrication to surfaces is coming to an end. In the functionalization of medical devices and implants, in addition to preventing non‐specific protein adsorption and cell adhesion, polymer‐brush formulations are often required to generate highly lubricious films. Poly(2‐alkyl‐2‐oxazoline) (PAOXA) brushes meet these requirements, and depending on their side‐group composition, they can form films that match, and in some cases surpass, the bioinert and lubricious properties of PEG analogues. Poly(2‐methyl‐2‐oxazine) (PMOZI) provides an additional enhancement of brush hydration and main‐chain flexibility, leading to complete bioinertness and a further reduction in friction. These data redefine the combination of structural parameters necessary to design polymer‐brush‐based biointerfaces, identifying a novel, superior polymer formulation.  相似文献   

13.
Seven crystal structures of five first‐row (Fe, Co, Ni, Cu, and Zn) and one second‐row (Cd) transition metal–4‐picoline (pic)–sulfate complexes of the form [M(pic)x]SO4 are reported. These complexes are catena‐poly[[tetrakis(4‐methylpyridine‐κN)metal(II)]‐μ‐sulfato‐κ2O:O′], [M(SO4)(C6H7N)4]n, where the metal/M is iron, cobalt, nickel, and cadmium, di‐μ‐sulfato‐κ4O:O‐bis[tris(4‐methylpyridine‐κN)copper(II)], [Cu2(SO4)2(C6H7N)6], catena‐poly[[bis(4‐methylpyridine‐κN)zinc(II)]‐μ‐sulfato‐κ2O:O′], [Zn(SO4)(C6H7N)2]n, and catena‐poly[[tris(4‐methylpyridine‐κN)zinc(II)]‐μ‐sulfato‐κ2O:O′], [Zn(SO4)(C6H7N)3]n. The Fe, Co, Ni, and Cd compounds are isomorphous, displaying polymeric crystal structures with infinite chains of MII ions adopting an octahedral N4O2 coordination environment that involves four picoline ligands and two bridging sulfate anions. The Cu compound features a dimeric crystal structure, with the CuII ions possessing square‐pyramidal N3O2 coordination environments that contain three picoline ligands and two bridging sulfate anions. Zinc crystallizes in two forms, one exhibiting a polymeric crystal structure with infinite chains of ZnII ions adopting a tetrahedral N2O2 coordination containing two picoline ligands and two bridging sulfate anions, and the other exhibiting a polymeric crystal structure with infinite chains of ZnII ions adopting a trigonal bipyramidal N3O2 coordination containing three picoline ligands and two bridging sulfate anions. The structures are compared with the analogous pyridine complexes, and the observed coordination environments are examined in relation to crystal field theory.  相似文献   

14.
15.
Four new solvent‐induced Ni(II) complexes with chemical formulae [{NiL(μ2‐OAc)(MeOH)}2Ni]·2MeOH ( 1 ), [{NiL(μ2‐OAc)}2(n‐PrOH)(H2O)Ni]·n‐PrOH ( 2 ), [{NiL(μ2‐OAc)(DMF)}2Ni] ( 3 ) and [{NiL(μ2‐OAc)(DMSO)}2Ni]·2DMSO ( 4 ), (H2L = 4‐Nitro‐4′‐chloro‐2,2′‐[(1,3‐propylene)dioxybis(nitrilomethylidyne)]diphenol) have been synthesized and characterized by elemental analyses, FT‐IR, UV–Vis spectra and X‐ray crystallography. X‐ray crystal structure determinations revealed that each of the Ni(II) complexes 1–4 consists of three Ni(II) atoms, two completely deprotonated (L)2? units, two μ2‐acetate ions and two coordinated solvent molecules (solvents are methanol, n‐propanol, water, N,N‐dimethylformamide and dimethyl sulphoxide, respectively). Although the four complexes 1–4 were synthesized in different solvents, it is worthwhile that the Ni(II) atoms in the four complexes 1–4 adopt hexa–coordinated with slightly distorted octahedral coordination geometries, and the ratios of the ligand H2L to Ni(II) atoms are all 2: 3. The complexes 1–4 possess self‐assembled infinite 1D, 3D, 1D and 2D supramolecular structures via the intermolecular hydrogen bonds, respectively. In addition, fluorescence behaviors were investigated in the complexes 1–4 .  相似文献   

16.
A 4‐methoxy‐substituted triphenylamine‐containing homopolymer, poly [N,N‐diphenyl‐4‐methoxyphenylamine‐4′,4′′‐diyl] ( PMeOTPA ), with blue light (435 nm) fluorescence quantum efficiency up to 79% was easily prepared by oxidative coupling polymerization of N,N‐diphenyl‐4‐methoxyphenylamine ( MeOTPA ) using FeCl3 as an oxidant. Its reversible oxidation redox couple was at 0.41 V versus Fc/Fc+ in acetonitrile solution. It exhibited good thermal stability with 10% weight‐loss temperatures above 500 °C under a nitrogen atmosphere and relatively high softening temperature (154 °C). The simply designed homopolymer revealed moderate stability of electrochromic characteristics, changing color from original pale yellowish to red, and then to black. The PMeOTPA based field effect transistor also showed p‐type characteristics with significant temperature dependence. The present study suggests that PMeOTPA is a multifunctional polymer for various optoelectronic device applications. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3292–3302, 2007  相似文献   

17.
This study investigates the resistive behavior of rod‐coated micrometer thick films of poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) on ultra‐low modulus (120– 130 kPa) polydimethylsiloxane (PDMS) substrate having scratch or microtrench‐type roughness patterns. On average, the films were found to remain electrically functional up to 23% axial strain with an average increase of three times in the value of the normalized resistance. The films were also found to remain conductive up to bending diameter of 4 mm with an average increase of 1.12 times their initial resistance. The rod‐coated PEDOT:PSS films on ultra‐low modulus PDMS having microtrench‐type roughness were also found to remain functional even after 1000 bending cycles at a bending diameter of 4 mm and even smaller with an increase in resistance that was on average 1.15 times their initial resistance. The films were found to fail firstly by cracking and thereby debonding from the substrate under the application of axial strain. On the other hand, the films exhibit no delamination under bending strains. The results from this investigation suggest that the polymer–polymer laminate has potential applicability in stretchable and flexible electronics and related applications. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 226–233  相似文献   

18.
Polydimethylacrylamides (PDMAs) end‐functionalized with hydrophobic groups were synthesized by the reaction of cesium salts of one‐ or two‐ended living PDMA anion with octadecanoyl and perfluorooctanoyl chlorides and with α‐phenylacrylate monomers containing an octadecyl group attached via oligooxyethylene spacers to the acrylate functionality. Size exclusion chromatography or NMR studies indicated that the end functionalizations were nearly quantitative. Reduced viscosity measurements were consistent with predominantly dimeric association of the perfluorooctanoyl‐end‐functionalized PDMAs. The association of the two‐ended, perfluorooctanoyl‐ and octadecanoyl‐functionalized polymers was more extensive and consistent with pairwise association. Furthermore, the presence of oligoethylene oxide spacers between the octadecyl and α‐phenylacrylate groups greatly enhanced the hydrophobic association of bis(octadecyl)‐end‐functionalized PDMA. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1403–1418, 2001  相似文献   

19.
A novel conjugated polymer, poly(thienylene‐vinylene‐thienylene) with cyano substituent ( CN‐PTVT ) was synthesized via Stille coupling for the application in air stable field‐effect transistor and polymer solar cell. The polymer was characterized by 1H NMR, elemental analysis, UV‐vis absorption and photoluminescence spectroscopy, TGA, cyclic voltammetry and XRD analysis. CN‐PTVT exhibits a good thermal stability with 5% weight loss at 306 °C. The FET hole mobility of the polymer reached 5.9 × 10?3 cm2 V?1 s?1 with Ion/Ioff ratio of 4.9 × 104, which is one of the highest performance among the air‐stable amorphous polymers. The polymer solar cell based on CN‐PTVT as donor and PCBM as acceptor shows a relatively high open‐circuit voltage of 0.82 V and a power conversion efficiency of 0.3% under the illumination of AM1.5, 100 mW/cm2. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4028–4036, 2009  相似文献   

20.
The synthesis of five homopolymers (PS)3 and the corresponding diblock copolymer 3‐arm stars of the (PS‐b‐P2VP)3 type is reported through atom transfer radical polymerization. Such star homo‐ and copolymers are prepared without any addition of solvent (bulk polymerization). The kinetics study results lead to the ability of predicting the best polymerization time with high values of monomer to polymer conversion, sufficient polydispersity indices and average molecular weights. Molecular characterization through size exclusion chromatography, viscometry, low‐angle laser light scattering, proton and carbon nuclear magnetic resonance spectroscopy (1H NMR and 13C NMR, respectively) verified the successful synthesis of both homopolymer and copolymer 3‐arm star‐like architectures. Furthermore, the morphological characterization of the final copolymers is reported through transmission electron microscopy studies verifying the self‐assembly without any indication of homopolymer or Cu(I) traces. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 23–32  相似文献   

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