首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 344 毫秒
1.
钟鸿  郭小芳  王瑞虎 《结构化学》2013,(9):1325-1333
Three Cd(II) coordination complexes,{[Cd(bime)3](NO3)2·(H2O)3}n(1),[Cd(bime)Br2]n(2) and [(H2bime)(CdBr4)(H2O)]n(3)(bime = 1,2-bis(imidazol-1-yl)ethane),have been prepared and characterized.Single-crystal X-ray diffraction analysis reveals that 1~3 crystallize in the trigonal space group P-3,monoclinic space group C2/c and triclinic space group P1,respectively.In 1,bime bridges six-coordinated Cd(II) to generate a two-fold interpenetrating 3D coordination polymer,in which NO3- is not involved in coordination,but serves as a void filler to balance the charge of the 3D framework.The six NO3- and six uncoordinated water molecules form an unprecedented 24-membered macrocycle through hydrogen bonding interaction.In 2,bime in an anti-conformation links the CdBr2 units into a zigzag chain.In 3,bime does not take part in coordination,but is protonated to act as a counter cation of [CdBr4 ]2-.The hydrogen bonds between H2bime and [CdBr4]2- result in the formation of a supramolecular chain.  相似文献   

2.
The electrochemical oxidation of 1,4-dihydroxyanthraquinone has been studied in the presence of acetylacetone and benzoylacetone as nucleophiles in a mixture of ethanol/water by means of cyclic voltammetry as a diagnostic technique.The results indicate the participation of electrochemically produced anthraquinone in the Michael addition reaction with acetylacetone and benzoylacetone to form the corresponding new anthraquinone derivatives.On the basis of the EC mechanism,the observed homogeneous rate constants(kobs)of the reaction of anthraquinone with acetylacetone and benzoylacetone were estimated by comparing the experimental cyclic voltammograms with the digitally simulated results.  相似文献   

3.
刘有芹  颜芸  沈含熙 《中国化学》2005,23(9):1165-1172
A thin film of manganese hexacyanoferrate (MnHCF) was electrochemically formed on a glassy carbon (GC) electrode to prepare a chemically modified electrode (CME). The mechanism of film formation of MnHCF and its growth process were investigated in detail by cyclic voltammetry. The results show that the stoichiometric composition of MnHCF is Mn^ⅢFe^Ⅲ(CN)6, an analogue of prussian yellow. There exist three clear-cut stages in the whole modification process and the last stage is indispensable to the fabrication of homogenized, stable MnHCF film and must last for an appropriate time. The surface morphology of MnHCF/GC electrode was characterized by scanning electron microscopy (SEM), which further verified the effective deposition of MnHCF film on GC. The kinetic constants of MnHCF/GC electrode process were also evaluated. The resulting MnHCF film modified electrode presented good stability and high electrocatalytic activity toward the oxidation of H2O2, indicating that MnHCF film possesses function of catalase and can be expected for analytical purposes.  相似文献   

4.
四种钌(Ⅱ)配合物的中心离子电化学行为的比较   总被引:2,自引:0,他引:2  
The electrochemical behavior of mononuclear and symmetrical binuclear ruthenium(Ⅱ) complexes [Ru1:Ru(bpy)2DIPB(ClO4)2,Ru2:(bpy)2 Ru(DIPB)Ru(bpy)2(ClO4)4,Ru3:Ru(phen)2DIPB(ClO4)2 and Ru4:(phen)2 Ru(DIPB)Ru (phen)2(ClO4)4] containing binuclear ligand 2,2′-bipyridine(bpy),1,10-phenanthroline(phen) and bridging ligand 1,4-di-[2-imidazo[4,5-f][1,10] phenanthroine benzene(DIPB) on a platinum electrode and the intermetallic interaction of binuclear complexes have been investigated using cyclic voltammetry,cyclic ac voltammetry and differential capacitance techniques,etc.In acetonitrile solution with a concentration of 0.1 mol穌m-3 TBAP,the central ions in four complexes all display single 1e and 2e reversible oxidation- reduction waves on the cyclic voltammograms,with apparent diffusion coefficients of the mononuclear complexed cations being larger than that of the binuclear ones.The apparent diffusion coefficients for complexed cations with auxiliary ligands bpy are also found to be larger than that with ligands phen.It appears that the overlapping of two continuous single-electron processes by cyclic ac voltammetry and differential capacitance techniques occurs during the redox processes of the central ions binuclear complexes.The results show that a weak electronic interaction exits between the two central ruthenium ions in binuclear complexes.  相似文献   

5.
The non-isothermal degradation kinetics of N,N'-di(diethoxythiophosphoryl)-1,4-phenylenediamine in N2 was studied by TG-DTG techniques.The kinetic parameters,including the activation energy and pre-exponential factor of the degradation process for the title compound were calculated by means of the Kissinger and Flynn-Wall-Ozawa(FWO)method and the thermal degradation mechanism of the title compound was also studied with the Satava-Sestak methods.The results indicate that the activation energy and pre-exponential factor are 152.61 kJ/mol and 9.06×101 4s -1with the Kissinger method and 154.08 kJ/mol with the Flynn-Wall-Ozawa method,respectively.It has been shown that the degradation of the title compound follows a kinetic model of one-dimensional diffusion or parabolic law,the kinetic function is G(α)=α2and the reaction order is n=2.  相似文献   

6.
In this work,we propose a new spin-coating method coupling with high thermal decomposition,to prepare the tin-antimony(Sn-Sb) oxide electrode.The character of the spin-coating electrode was compared with the dip-coating electrode through X-ray diffraction(XRD),scanning electron microscopy(SEM),accelerated life test,cyclic voltammetry,and electrolytic degradability. The results showed that the spin-coating electrode had a better defined crystal form,a smoother and more compact surface than that of the dip-coating electrode.Service time of the spin-coating electrode was determined to be longer than 15 h,and it was less than 2 min for the dip-coating electrode.Electrochemical characterization analysis showed that the electrolytic degradability of the spin-coating electrode is better than that of the dip-coating electrode.  相似文献   

7.
The kinetic characteristics of the concentrated Ⅴ(Ⅳ)/Ⅴ(Ⅴ) couple have been studied at a glassy carbon electrode in sulfuric acid using rotating-disc electrode and cyclic voltammetry. The kinetics of the Ⅴ(Ⅳ)/Ⅴ(Ⅴ) redox couple reaction was found to be electrochemically quasi-reversible with the slower kinetics for the Ⅴ(Ⅴ) reduction than that for the Ⅴ(Ⅳ) oxidation. And, dependence of diffusion coefficients and kinetic parameters of Ⅴ(Ⅳ) species on the Ⅴ(Ⅳ) and H2SO4 concentration was investigated. It is shown that the concentration of active species Ⅴ(Ⅳ) should be over 1 mol·L^-1 for the redox flow battery application. Further, with increasing the Ⅴ(Ⅳ) and H2SO4 concentration, the diffusion coefficients of Ⅴ(Ⅳ) were gradually reduced whereas its kinetics was improved considerably, especially in the case of Ⅴ(Ⅳ) and H2SO4 up to 2 and 4 mol·L^-1.  相似文献   

8.
寇兴明  胡艳  黄忠  孟祥光  曾宪诚 《中国化学》2005,23(10):1303-1308
The catalytic hydrolysis of bis(4-nitrophenyl)phosphate (BNPP) by lanthanum(Ⅲ) ion in the presence of amino-alcoholic ligands: diethanolamine (DEA) and triethanolamine (TEA), was investigated kinetically at 30 ℃. The results indicated that the dinuclear dihydroxo complexes formed by lanthanum(Ⅲ) ion with aminoalcoholic ligands might be the catalytically active species which catalyze the hydrolysis of BNPP to different extents and the catalytic mechanism was believed to involve the synergism of double Lewis acid activation of the substrate and an intramolecular nucleophilic attack of a bridging oxo ligand.  相似文献   

9.
The hydrothermal reaction of Cd(OAc)2.H2O with 1,2-benzenedicarboxylate (1,2-BDC), imidazole and H2O resulted in the formation of a binuclear polymeric Cd( Ⅱ ) complex {[Cd2(1,2-BDC)2(Im)4].(H2O)}n which was then characterized by elemental analyses and single-crystal X-ray diffraction analysis. The crystal is of monoclinic system, space group P21/c with a = 14.6455(3), b = 9.3530(2), c = 23.7838(5)A, β= 106.6290(10)°, Cl12H104CdgN32O36, Mr = 3373.47, V = 3121.64(11)A^3, Dc = 1.795 g/cm^3, F(000) = 1672,μ= 1.428 cm^-1 and Z = 1. The final R = 0.0316 and wR = 0.0687 for 5045 reflections with I 〉 2σ(I). In the title complex, the two Cd( Ⅱ) ions are in different coordination environments with distorted octahedral and pengonal bipyramidal geometries, respectively. Two Cd polyhedra are linked together through one μ2-η^1:η^1 and one μ2-η^1:η^1 carboxylate groups from different 1,2-BDC ligands, giving rise to a binuclear Cd( Ⅱ ) cluster, and such clusters are connected by bridged 1,2-BDC ligands to form a 2-D structure along the c axis. The inter- and intermolecular hydrogen bonds further connect the 2-D structures into a 3-D supramolecular network.  相似文献   

10.
The electrochemical oxidation of diphenylamine in acetonitrile produces an adherent uniform polymer film which exhibits mutiple colour variation(yellow-green-blue) in a wide range of potential scan. The polymerization mechanism and the structure of the polymer were studied by cyclic voltammetry, FT-IR and in situ ESR. The results indicate that the electrochemical polymerization of diphenylamine belongs to a cationic radical polymerization process. During electrolysis, only oligomers were initialy produced, then polymer film was formed on the electrode surface. The electropolymerization performs via the 4,4' C-C phenyl-phenyl coupling mechanism.  相似文献   

11.
In the crystal structure of the title complex, poly­[[di­azido­manganese(II)]‐di‐μ‐1,2‐bis­(imidazol‐1‐yl)­ethane‐κ4N3:N3′], [Mn(N3)2(C8H10N4)2]n or [Mn(N3)2(bim)2]n, where bim is 1,2‐­bis(imidazol‐1‐yl)­ethane, each MnII atom is six‐coordinated in a distorted octahedral coordination environment to four N atoms from four bim ligands and two N atoms from two azide ligands. The MnII atoms, which lie on inversion centres, are bridged by four bim ligands to form a two‐dimensional (4,4)‐network. The azide ligands are monodentate (terminal).  相似文献   

12.
Several dimeric 1,2-bis (2,2′-bipyridinyl)ethane (1,2,6,7, and 9 and 1,2-bis(1,10-phenanthrolinyl)) ethane (3,4, and 5) ligands have been synthesized in high yield by oxidative coupling of the corresponding monomeric methylene carbanions using as oxidating agents Br2, I2, and 1,2-dibromoethane. The structure of the compounds obtained from three tetramethyl-2,2′-bipyridines and one tetramethyl-1,10-phenanthroline have been assigned on the basis of their 1H-NMR spectra. The electronic absorption and emission properties of these new ligands are reported. They display intense fluorescence spectra.  相似文献   

13.
In the adduct 1,2‐bis(4‐pyridyl)­ethane–1,1,1‐tris(4‐hydroxy­phenyl)­ethane (1/2), C12H12N2·2C20H18O3, the bipyridyl component lies across an inversion centre in P. The tris‐phenol mol­ecules [systematic name: 4,4′,4′′‐(ethane‐1,1,1‐triyl)­triphenol] are linked by O—H?O hydrogen bonds to form sheets built from R(38) rings, and symmetry‐related pairs of sheets are linked by the bipyridyl mol­ecules via O—H?N hydrogen bonds to form open bilayers. Each bilayer is interwoven with two adjacent bilayers, forming a continuous three‐dimensional structure. In the adduct 1,2‐bis(4‐pyridyl)­ethene–1,1,1‐tris(4‐hydroxy­phenyl)­ethane–methanol (1/1/1), C12H10N2·C20H18O3·CH4O, the mol­ecules are linked by O—H?O and O—H?N hydrogen bonds into three interwoven three‐dimensional frameworks, generated by single spiral chains along [010] and [001] and a triple‐helical spiral along [100].  相似文献   

14.
In the title coordination polymer, [Pb(NCS)2(C12H12N2)], the coordination geometry about the PbII atom is a distorted octahedron, composed of two N atoms from bpe ligands [bpe is 1,2‐bis(4‐pyridyl)ethane], two other N atoms from NCS? groups and two neighbouring S atoms through short contacts. The trans‐bpe ligands act as bridges between two PbII centres resulting in the formation of a linear chain. The terminal S atoms of the NCS? ligands make short contacts with the PbII atom of neighbouring chains to form an infinite two‐dimensional polymeric structure.  相似文献   

15.
A new mercury(II) complex of 1,2‐bis(4‐pyridyle)ethene (bpe) with anionic acetate and thiocyanate ligands has been synthesized and characterized by elemental analysis, IR, 1H NMR and 13C NMR spectroscopy. The single crystal X‐ray analysis shows that the complex is a two‐dimensional polymer with simultaneously bridging 1,2‐bis(4‐pyridyle)ethane, acetate and thiocyanate ligands and basic repeating dimeric [Hg2(μ‐bpe)(μ‐OAc)2(μ‐SCN)2] units. The two‐dimensional system forms a three‐dimensional network by packing via ππ stacking interactions.  相似文献   

16.
The title compound, [Cu2(SO4)2(C10H8N2)2(C2H6O2)2(H2O)2]n, contains two crystallographically unique CuII centres, each lying on a twofold axis and having a slightly distorted octahedral environment. One CuII centre is coordinated by two bridging 4,4′‐bipyridine (4,4′‐bipy) ligands, two sulfate anions and two aqua ligands. The second is surrounded by two 4,4′‐bipy N atoms and four O atoms, two from bridging sulfate anions and two from ethane‐1,2‐diol ligands. The sulfate anion bridges adjacent CuII centres, leading to the formation of linear ...Cu1–Cu2–Cu1–Cu2... chains. Adjacent chains are further bridged by 4,4′‐bipy ligands, which are also located on the twofold axis, resulting in a two‐dimensional layered polymer. In the crystal structure, extensive O—H...O hydrogen‐bonding interactions between water molecules, ethane‐1,2‐diol molecules and sulfate anions lead to the formation of a three‐dimensional supramolecular network structure.  相似文献   

17.
The ligand [1,2‐bis(4‐pyridinecarboxamido)ethane] (L) and the coordination polymer |[Cu(L)2(H2O)]‐(NO3)2·6H2O|·(1) haw been synthesized and characterized by ER and 1H NMR spectra. Their molecular structures and the packing of 1 have been determined by single‐crystal X‐ray diffraction analysis. The Cu(n) in 1 is bridged by two ligands forming an infinite one‐dimensional chain like structure and L in 1 adopts a different conformation from its free state. 1 belongs to monoclinic, space group P21/n, a = 1.2896(3) nm, b = 1.2552(8) nm, c = 2.2903(19) nm, β = 93.04(5)°, Z = 4, V = 3.702(4) nm3. The TG and DTG experiments showed that the uncoordinated H2O can be removed at low temperature by heating, and it does not decompose until 250 °C.  相似文献   

18.
The preparation and characterization of three metal(II) chlorido complexes with 1,2‐di(1H‐tetrazol‐1‐yl)ethane (dte) ( 1 ) as ligand is presented. The complexes have the following formula: [CoCl2(μ‐dte)(dte)2]n ( 2 ), [CuCl2(μ‐dte)2]n ( 3 ), and [Cd(μ‐Cl)2(μ‐dte)]n ( 4 ). Single crystal X‐ray diffraction of all three metal complexes was performed and the structures are discussed. All three central metal atoms are connected to polynuclear structures by the μ‐bridging ligand. Cobalt and copper are connected to one‐dimensional chains. The central cadmium(II) atoms are additionally connected by the chloride anions to a two‐dimensional network. Further, the cobalt(II) complex represents a special case with two terminal dte ligands.  相似文献   

19.
A new one‐dimensional platinum mixed‐valence complex with nonhalogen bridging ligands, namely catena‐poly[[[bis(ethane‐1,2‐diamine‐κ2N,N′)platinum(II)]‐μ‐thiocyanato‐κ2S:S‐[bis(ethane‐1,2‐diamine‐κ2N,N′)platinum(IV)]‐μ‐thiocyanato‐κ2S:S] tetrakis(perchlorate)], {[Pt2(SCN)2(C2H8N2)4](ClO4)4}n, has been isolated. The PtII and PtIV atoms are located on centres of inversion and are stacked alternately, linked by the S atoms of the thiocyanate ligands, forming an infinite one‐dimensional chain. The PtIV—S and PtII...S distances are 2.3933 (10) and 3.4705 (10) Å, respectively, and the PtIV—S...PtII angle is 171.97 (4)°. The introduction of nonhalogen atoms as bridging ligands in this complex extends the chemical modifications possible for controlling the amplitude of the charge‐density wave (CDW) state in one‐dimensional mixed‐valence complexes. The structure of a discrete PtIV thiocyanate compound, bis(ethane‐1,2‐diamine‐κ2N,N′)bis(thiocyanato‐κS)platinum(IV) bis(perchlorate) 1.5‐hydrate, [Pt(SCN)2(C4H8N2)2](ClO4)2·1.5H2O, has monoclinic (C2) symmetry. Two S‐bound thiocyanate ligands are located in trans positions, with an S—Pt—S angle of 177.56 (3)°.  相似文献   

20.
Platinum antitumour agents, containing aromatic rings, which are used for targeting DNA in effective therapies for the treatment of cancer. We have synthesized the title metallocomplex with an aromatic ligand and determined its crystal structure. In many cases, complexes of platinum and other metals have a symmetrical structure. In contrast, the platinum(II) complex with pyridine and N‐(9‐anthracenylmethyl)‐1,2‐ethanediamine as ligands (systematic name: cis‐{N‐[(anthracen‐9‐yl)methyl]ethane‐1,2‐diamine‐κ2N ,N ′}bis(pyridine‐κN )platinum(II) dinitrate), [Pt(C5H5N)2(C17H18N2)](NO3)2, is asymmetric. Of the two pyridine ligands, only one is π‐stacked with anthracene, resulting in an asymmetric structure. Moreover, the angle of orientation of each pyridine ligand is variable. Further examination of the packing motif confirms an intermolecular edge‐to‐face interaction.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号