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 468 毫秒
1.
The oxygenation constants(Ko_2)of cobalt(Ⅱ)hydroxamates(CoL_2~1-CoL_2~3)with benzo-15-crown-5(B15C5)pendants were measured over the range of-5 to 20℃,and the values of thermodynamic parameters(ΔH~0 andΔS~0)were calculated based on these(No_2)values.Meanwhile,these crowned complexes were employed to the oxidation for p-xylene to p-toluic acid with air at 110Δunder normal atmospheric pressure.The effects of B15C5 pendant and the length of chain bonded to B15C5 in these complexes on the O_2-binding capabilities and oxidation for p-xylene were investigated with the comparison of crown-free analogues CoL_2~4.  相似文献   

2.
The synthesis and characterization of two new aluminate(Ⅲ) complexes with general formula K[AlCl3X] are reported. These compounds derived from aluminate trichloride and related salts. Potassium trichlorothiocyanoaluminate, PCTA, and potassium trichlorocyanatoalu-minate, PCCA, are two new ionic aluminate complexes. They can be easily synthesized in a nearly quantitative yield by using the direct reaction of AlCl3 and KX. The complexes were characterized by physico-chemical and spectroscopic methods. Theoretical calculations have been used for the extraction of structural and spectroscopic data of these new synthesized complexes. The antibacterial activities of such compounds were studied against the Staphylococcus aureus, Escherichia coli, Staphylococcus Epidermidis, Estreptococo B and Shigella.  相似文献   

3.
Two new mixed-ligand ruthenium(Ⅱ) complexes,Ru(dcbpy)-(LL)NCS)2[where dcbpy=4,4‘-dicarboxyl-2,2‘‘-bipyridine,LL=4,4‘-bis(N-methyl-anilinomethyl)-2,2‘‘-bipyridine(2)],were synthesized,and the tphotophysical properties of these complexes were studied.The metal-to-ligand charge transfer (MLCT) transitions of these complexes exhibited solvatochromic effect due to the existence of NCS ligands.The MLCT energies also strongly depend on the pH values of the solutions because of protonation and deprotonation of the carboxyl groups.The pKa values of the ground state,4.0 for 1 and 3.8 for 2,were obtained from the titration curves.The photoelectrochemical properties of 1 and 2 as sensitizers in sandwich-type solar cells have been studied.Complex 1 exhibited better photoelectrochemical behavior than complex 2 as expected.It was proved that the design of mixed-ligand complex by introducing electron donating group in one of the ligands should be a promising approach.  相似文献   

4.
4-Morpholinoacetophenone thiosemicarbazone, MAPT, and its nickel(Ⅱ) and copper(Ⅱ) complexes have been prepared and characterized by elemental analysis, magnetic susceptibility, spectral methods (FT-IR, ^1H NMR) and cyclic voltammetry. Electrochemical behaviors of the complexes have been studied by cyclic voltammetry in DMF media showing metal centered reduction processes for both of them. The redox properties, nature of the electrode processes and the stability of the complexes were discussed. [Cu(MAPT)2]Cl2 complex shows Cu(Ⅱ)/Cu(Ⅰ) couple and quasi-reversible wave associated with the Cu(Ⅲ)/Cu(Ⅱ) process. The reduction/oxidation potential values depend on the structures of complexes. Also, the antimicrobial activities of these complexes were determined against S. aureus, E. coli and B. subtilis.  相似文献   

5.
Oxidation reaction of [Ru(PPh3)3Cl2] with tetraethylthiuram disulfide [Et2NCS2]2 or tetra-iso-propylthiuram disulfide [iPr2NCS2]2 afforded ruthenium(Ⅲ) complexes [Ru(PPh3)2(S2CNR2) Cl2]·CH2Cl2(R=Et 1,iPr 2) which were characterized by single-crystal X-ray diffraction.Complex 1 crystallizes in triclinic,space group P with a = 11.5065(6),b = 12.1458(7),c = 18.0034(9) ,α = 109.380(4),β = 95.279(4),γ = 97.969(4)°,V = 2324.8(2) 3 and Z = 2.Complex 2 belongs to the monoclinic system,space group P21/n with a = 12.5752(3),b = 20.7562(5),c = 17.6821(3) ,β = 105.934(1)°,V = 4437.94(17) 3 and Z = 4.Both mononuclear complexes 1 and 2 have an octahedral configuration around the central ruthenium atom which is bonded to one chelated dithiocarbamate ligand,two PPh3 ligands in mutually trans and two chlorides in mutually cis positions.The average Ru-S,Ru-P and Ru-Cl bond lengths are 2.377(2),2.412(2) and 2.369(2)  for 1,and 2.376(2),2.414(1) and 2.383(2)  for 2,respectively.The electrochemical properties of these two complexes were studied in CH2Cl2 solution by cyclic voltammetry.  相似文献   

6.
A simple and effective procedure for the enantioselective synthesis of (R)- and (S)-moprolol was described. The key step was the asymmetric synthesis of enantiopure (R)- and (S)-guaifenesin, which were synthesized from enantioenriched (R)-3-chloro-l,2-propanediol and (S)-epichlorohydrin via kinetics of hydrolysis resolution of racemic epichlorohydrin by chiral Salen-Co^Ⅲ complex. The e.e. values of both the optical compounds were above 98%, and the chemical structures of the target compounds were confirmed by ^1H NMR, ^13C NMR, IR, and MS.  相似文献   

7.
8.
The chemistry of silylene-transition-metal complexes LnM(=SiR2)SiR3 is one of the attractive synthetic targets in organometallic chemistry for such complexes are key intermediates in many transition metal-catalyzed systems.In the present work,the novel insertion reactions of an isocyanide into the Cp*Mo(CO)2(=SiMe2)(SiMe3) Si-C bond were investigated extensively by using the DFT method.The effective core potentials(ECP) with a double-ζ valence basis set(LanL2DZ) were employed for Mo and Si and the standard 6-31G basis set for all other atoms.Polarization functions[22] were added for Si(ζd = 0.262),C(ζd = 0.8) and N(ζd = 0.8).The effect of solvent was evaluated with the standard PCM model.Our calculations show that the two-step channel is energetically favorable,and the solvation mode has minor influence on the relative energies.  相似文献   

9.
Three novel metal-organic complexes with formulas [Ni(C9N2O2H7)2(CH3OH)2](1),[Zn(C9N2O2H7)2(H2O)2](2) and [Cd(C9N2O2H7)2(CH3OH)2](3) were synthesized by the reactions of Ni,Zn and Cd salts with ethyl 2-benzimidazolylacetate under hydrothermal conditions or layering technique,and characterized by single-crystal X-ray diffraction analysis,IR spec-troscopy,solid-state luminescent properties and thermogravimetric(TG) analysis.The crystal data for these three complexes are as follows:for 1,monoclinic,space group P21/c,a = 9.384(3),b = 9.634(3),c = 11.292(3) ,β = 95.787(5)°,V = 1015.7(5) 3,Z = 2,F(000) = 492,Dc = 1.547 Kg/m3,μ = 1.002 mm-1,the final R = 0.0451 and wR = 0.0900 for 1833 observed reflections with Ⅰ 2σ(Ⅰ);for 2,orthorhombic,space group Pbca,a = 10.031(4),b = 10.379(4),c = 17.525(7),V = 1824.6(12) 3,Z = 4,F(000) = 928,Dc = 1.645 Kg/m3,μ = 1.392 mm-1,the final R = 0.0452 and wR = 0.0996 for 1661 observed reflections with Ⅰ 2σ(Ⅰ);for 3,monoclinic,space group P21/c,a = 9.9114(13),b =10.4852(15),c = 10.4120(14) ,β = 108.453(5)°,V = 1026.4(2) 3,Z = 2,F(000) = 532,Dc = 1.705 Kg/m3,μ = 1.110 mm-1,the final R = 0.0322 and wR = 0.0805 for 1822 observed reflections with Ⅰ 2σ(Ⅰ).In the three complexes,the ethyl 2-benzimidazolylacetate shows the same chelating mode,and the adjacent units are interlinked into a two-dimensional layer through hydrogen-bonds(O-H···O,N-H···O).  相似文献   

10.
A novel ligand of DTPA-dihydropyridine derivative was synthesized by reaction of DTPA-dianhydride with 4-aniline-1,4-dihydropyridine. Its complexes of gadolinium, manganese and iron were prepared. Their spin-lattice relaxivities (T1) were investigated. The results show that the NMR T1 relaxivitives (R1) for complexes of Fe(Ⅲ), Mn(Ⅱ) are less than that of Gd(Ⅲ) complex, which has a high relaxivity (R1) on the surrounding water protons, indicating that the Gd(Ⅲ) complex possesses the precondition to be contrast agents for magnetic resonance imaging.  相似文献   

11.
A novel complex of monomeric thallium (Ⅲ) with the nitrogen donor ligand phenanthroline (phen) has been prepared and characterized by multimuclear NMR(^1H,^13C,^205Tl). The three complexes exist in equilibria in DMSO and acetonitrile solution, which was proved by the ^205Tl NMR spectra. The ^1H and ^13C NMR spectra of tris-phen T1(Ⅲ) complex have been measured, where the spin-spin coupling between T1(I=1/2) and ^13C or ^1H signals were observed with the ^1H and ^13C NMR spectroscopy in acetonitrile. The coupling constants are presented and the chemical shifts of complexes are discussed in detail.  相似文献   

12.
Nine homobinuclear lanthanide complexes with macrocyclic Schiff base were prepared by condensing 2, 6-diacetylpyridine and 1, 3-diamino-2-hydroxypropane in the presence of template lanthanide metal ions. These complexes were characterized by elemental analysis, IR, molar conductance and magnetic susceptibility. The variable-temperature magnetic susceptibility (4-300 K) of complexes of Gd( Ⅲ ) and Dy( Ⅲ ) was determined. A satisfactory fit to theoretical curve derived from spin Hamiltonian operator was obtained using least-squares method. The exchange interaction parameters are J=-0.26 cm-1, g=1.98 and △=0.06 cm-1, Z.J'=-0. 21 cm-1,g'=1.33 for Gd( Ⅲ ) and Dy( Ⅲ ), respectively. The results indicate a very week antiferromagnetic interaction between Gd( Ⅲ )-Gd( Ⅲ ) and Dy( Ⅲ )-Dy( Ⅲ ) ions.  相似文献   

13.
Density functional method was used to investigate the IR spectrum,heat of formation and thermal stability of a new energetic material bis(2,2-dinitropropyl) formal(BDNPF).The detonation velocity and pressure were evaluated by using the Kamlet-Jacobs equations based on the theoretical density and heat of formation.The bond dissociation energies for the weakest bonds were analyzed to investigate the thermal stability of the title compound.The results show that the C(1)-N(1) bond is predicted to be the trigger bond during pyrolysis.The crystal structure obtained by molecular mechanics belongs to the P21 space group,with the lattice parameters to be Z = 2,a = 11.5254,b = 6.2168,c = 9.5000  and ρ= 1.66 g/cm3.  相似文献   

14.
The present paper covers the synthesis and the characterization of ligand 2-decyl-3, 6, 9-tris (car-boxymethyl)-3,6,9-triazaundecan-1,11-dioic acid, HsL, and its Gd (Ⅲ) chelate. The protonation constantsfor HsL(IgKi^H= 10. 90, 8.50, 4.55, 2.92., 2.20) and the stability constant for GdL^2- (lgKGdL^2- = 2.2.80)were determined by means of potentiometric titration. They are similar to the corresponding values of DTPAand Gd-DTPA, respectively. The results obtained show that the basicity of the ligand and the stability con-stant of its Gd (Ⅲ) chelate are not obviously altered after the introduction of a linear chain decyl group intothe terminal acetic acid residue of DTPA. The Gd(Ⅲ) chelate may be a potential contrast agent with liver-specificity for magnetic resonance imaging(MRI).  相似文献   

15.
 Inverse gas chromatographic technique (IGC) was attempted as a new approach to follow the chemical changes that occur during lubricating base oil oxidation. Three groups of the oxidized base oils were prepared at different oxygen flow rates, periods and temperatures according to IP48 method. The corrected retention volumes (VR) were calculated for a series of selected test solutes possessing different functional groups on the oxidized base oils used as stationary phases. Kovats retention index (I), Flory-Huggins interaction parameter (κ∞1,2), and partial molar free energy of solution (ΔG∞L), were calculated for the given test solutes from their VR. The relationships between the I values and the oxidation variables were plotted and discussed. The obtained results were confirmed by potentiometric titration. The study reveals that the magnitudes of variation of I, κ∞1,2 or ΔG∞L retention parameters depend on the oxidation degree of the base oil. Large differences between the I values permit discrimination between the different oxidation steps.  相似文献   

16.
王崇臣  王鹏 《结构化学》2011,30(6):811-818
The title complexes(NH4)[Ag(dpe)(H2bptc)](1) and Ag2(bpy)(ox)·7H2O(2) were synthesized via slow evaporation at room temperature,and characterized by elemental analysis and infrared spectra.The crystal of 1 crystallizes in triclinic,space group P1 with a = 8.3959(7),b = 11.8088(12),c = 12.8175(13) ,α = 85.507(2),β = 79.245(1),γ = 84.174(2)o,V = 1239.7(2) 3,Z = 2,C28H22AgN3O8,Mr = 636.36,Dc = 1.705 g/cm3,F(000) = 644 and μ(MoKα) = 0.874 mm-1.The final R = 0.0479 and wR = 0.1426 for 3632 observed reflections with I > 2σ(I) and R = 0.0559 and wR = 0.1503 for all data.The crystal of 2 crystallizes in orthorhombic,space group Pnna with a = 17.2291(17),b = 7.5289(6),c = 21.369(2),V = 2771.9(4) 3,Z = 4,C22H30Ag2N4O11,Mr = 742.24,Dc = 1.779 g/cm3,F(000) = 1488 and μ(MoKα) = 1.476 mm-1.The final R = 0.0648 and wR = 0.2058 for 1996 observed reflections with I > 2σ(I) and R = 0.0769 and wR = 0.2192 for all data.X-ray diffraction reveals that in complexes 1 and 2,both 1,2-di(4-pyridyl)ethylene and 4,4'-bipyridine act as typical bidentate N-donor ligands to link two Ag centers.3,3'4,4'-Biphenyltetracarboxylate and oxalate anions play the role of organic linkers and counter-ions to balance the cationic charge of AgI.The rich hydrogen-bonding interactions and ligand-unsupported Ag…Ag interactions as well as π-π stacking interactions contribute to the construction of three-dimensional sandwich-like frameworks.  相似文献   

17.
Two novel energetic coordination compounds Zn2(DAT)5(H2O)3(TNR)2 and Co2(DAT)5(H2O)3(TNR)2 were synthesized and their structures were characterized by elemental analysis and FT-IR spectroscopy.The crystal structures were determined by single-crystal X-ray diffraction.The results reveal that the compounds have similar molecular structures and the crystals belong to the triclinic system,space group P with a = 11.491(3),b = 13.564(3),c = 15.496(3) ,V = 2180.4(8) 3,C17H28 Zn2N36O19,Mr = 1203.02 g·mol-1,Dc = 1.832 g·cm-3,μ(MoKα) = 1.221 mm-1,F(000) = 1223,Z = 2,R = 0.0596 and wR = 0.1514 for 11289 observed reflections(I > 2σ(I)) for Zn2(DAT)5(H2O)3(TNR)2 and a = 11.5291(13),b = 13.4894(15),c = 15.4852(17) ,V = 2164.8(4) 3,C17H28Co2N36O19,Mr = 1190.14 g·mol-1,Dc = 1.826 g·cm-3,μ(MoKα) = 0.888 mm-1,F(000) = 1211,Z = 2,R = 0.0576 and wR = 0.1431 for 11218 observed reflections(I > 2σ(I)) for Co2(DAT)5(H2O)3(TNR)2,respectively.The thermal decomposition characteristics of the com-pounds were investigated using differential scanning calorimetry and thermal gravimetry-diffediffer-rential thermal gravimetry.The results of thermal decomposition processes were similar for the two compounds.Both undergo four-step decomposition after the loss of coordinated H2O molecules.The final solid residues for the two DAT complexes were the corresponding metal oxides.The kinetic parameter of the first exothermic process of the compounds was studied by applying the Kissinger and Ozawa-Doyle methods.The thermodynamic parameters of the activation could be calculated.Sensitivity tests revealed that Co2(DAT)5(H2O)3(TNR)2 was more sensitive than Zn2(DAT)5(H2O)3(TNR)2.  相似文献   

18.
Inverse gas chromatographic technique ( IGC ) was attempted as a new approach to follow the chemical changes that occur during lubricating base oil oxidation. Three groups of the oxidized base oils were prepared at different oxygen flow rates, periods and temperatures according to IP48 method. The corrected retention volumes ( VR ) were calculated for a series of selected test solutes possessing different functional groups on the oxidized base oils used as stationary phases. Kovats retention index (Ⅰ), Flory-Huggins interaction parameter ( K^∞ 1,2 ), and partial molar free energy of solution ( △GL^∞ ), were calculated for the given test solutes from their VR. The relationships between the Ⅰ values and the oxidation variables were plotted and discussed. The obtained results were confirmed by potentiometric titration. The study reveals that the magnitudes of variation of Ⅰ, K^∞ 1,2 or △GL^∞ retention parameters depend on the oxidation degree of the base oil. Large differences between the Ⅰ values permit discrimination between the different oxidation steps.  相似文献   

19.
曹迁永甘欣  傅文甫 《中国化学》2004,22(11):1283-1287
The mono- and binuclear Cu(Ⅰ) complexes with substituted 2,2′-bipyridine and iodide ligands, [CuL2]BF4(L=4-methoxycarbonyl-6-(4-methylphenyl)-2,2′-bipyridine (a), 6-(4-hydroxymethylphenyl)-2,2′-bipyridine (b) and 6-(4-methoxylphenyl)-2,2′-bipyridine (c)) and [Cu2(μ-I)2L2] were prepared, and the crystal structures of the complexes were obtained from signal-crystal X-ray diffractional analysis. The spectroscopic properties of the complexes in dichloromethane are dominated by low energy MLCT bands from 360 to 650 nrn. The electrochemical studies of mononuclear complexes reveal that the complexes have stable copper(Ⅰ) state.  相似文献   

20.
Introduction A series of lanthanide sulfide complexes have beenlargely used for ceramics and thin film materials1 andthese complexes could be prepared from the precursorswhich are the compounds containing lanthanide-sulfurbonds.2-4 For instance, the compounds synthesized with[(alkyl)2dtc]-, phen?H2O and lanthanide salts were usedas the volatile precursors for preparing lanthanide sul-fide, its friction properties in lubricant was investigatedin literature 5 and the preparation and propertie…  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