共查询到20条相似文献,搜索用时 31 毫秒
1.
Polyamide-1010 samples were irradiated in vacuum at room temperature by Cobalt-60 γ-rays. The free radicals formed in irradiation were studied by means of electron spin resonance (ESR)techniques.The ESRspectra consisted of a quartet and a superimposed singlet which were attributed to radical -CO-NH-CH-CH_2 and -CH_2-C=O, respectively. The effects of temperature and crystaUinity on the radicals were discussed and the mechanism for the production and decay of the radicals was also proposed. 相似文献
2.
《Journal of Coordination Chemistry》2012,65(3):167-173
Abstract Crystals of [Zn(trien)I]I (trien=triethylenetetramine C6N4H18) are orthorhombic. The space group is P212121, with four molecules in the unit cell of dimensions a=11.97(1), b=13.72(1), c=8.12(1)Å. A total of 2029 independent reflections was measured with a Siemens A.E.D. automatic diffractometer using MoKα radiation. The structure was refined by full-matrix least-squares to a conventional R factor of 0.041 for 1435 observed reflections. The coordination around the central zinc atom is square pyramidal with the zinc atom 0.71 Å above the plane of the four nitrogen atoms of the ligand molecule. The values of coordination bond lengths, Zn-N(prim) 2.13 Å, Zn-N(sec) 2.19 Å, Zn-I 2.59 Å fall all in the range expected for covalent bonds. The molecular structure is discussed in comparison with that of [Cu(trien)SCN]CNS. 相似文献
3.
《Journal of Coordination Chemistry》2012,65(4):433-444
Abstract Spectroscopic changes observed on addition of nitrite to solutions of cobalt(II) tetra-sulfophthalocyanine ([Co(II)TSPc]4-) in the presence of N? 3 or ClO? 4 are reported. There is spectroscopic evidence for the oxidation of [Co(II)TSPc]4- to a [Co(III)TSPc]3- species in the presence of nitrite ions. Equilibrium and kinetic studies for the interaction between [Co(II)TSPc]4- and NO? 2 are reported. The rate was found to be first order in both [Co(II)TSPc]4- and NO? 2. The rate constant for the forward reaction, k f=1.6 × 10?4 dm3mol?1s?1 was determined at 20°C for the interaction between nitrite ions and [Co(II)TSPc]4- in the presence of NO3 ? or ClO4 ? ions. 相似文献
4.
Lorenzo-Luis P. A. Castellón E. R. Jiménez J. J. Gili P. 《Journal of Thermal Analysis and Calorimetry》1999,55(3):779-788
Molybdotellurates [M(H2O)6]3·[TeMo6O24], with M=Ni(II) and Co(II), were synthesized and characterized by single-crystal X-ray diffraction for compound 1 and X-ray
powder diffraction for compound 2, EDAX, IR, electronic spectra in the solid phase and in solution, and magnetic properties.
Thermogravimetry and differential scanning calorimetry of both compounds revealed a loss of 11 water molecules through an
endothermal process with ΔH=800 kJ mol−1 for the nickel compound and ΔH=833 kJ mol−1 for the cobalt compound. The residual compounds were characterized by chemical analysis, IR and XPS spectroscopy
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
5.
6.
7.
Bhojya Naik H. S. Siddaramaiah Ramappa P. G. 《Journal of Thermal Analysis and Calorimetry》1999,55(3):841-849
The complexes of cobalt(II) with dothiepin (DOT) hydrochloride have been studied for kinetics of thermal degradation by thermogravimetric
analysis (TG) and derivative thermogravimetric studies (DTG) in a static nitrogen atmosphere at a heating rate of 10° C min−1. A general mechanism of thermal decomposition is advanced involving dehydration and decomposition process for both organic
and inorganic ligands. The thermal degradation reactions were found to proceed in three steps having an activation energy
in the range 6.75–170 kJ mol−1. Thermal decomposition kinetics parameters were computed on the basis of thermal decomposition data.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
8.
9.
众所周知,超增感机理在感光化学中起着极其重要的作用,因此成为广大感光科学工作者研究的一大热点,先后提出了各自的设想。 相似文献
10.
《Journal of Coordination Chemistry》2012,65(3-4):269-279
Abstract The syntheses and crystal structures of [Co(nic)2(H2O)4] (1). [Co(iso)2(H2O)4] (2). [Cu(nic)2(H2O)4] (3), and [Cu(iso)2(H2O)4] (4) (nic = nicotinate; iso = isonicotinate) are reported. Complex 1 crystallizes in monoclinic, space group C2/m with cell parameters a =14.150(4). b = 6.883(2)., c = 8.497(2) Å, β= 118.28(2)° and Z = 2. The other crystals. 2. 3. and 4. are all triclinic, Pī; a = 9.777(3), b = 6.348(4), c = 6.888(3)Å, a= 113.10(6)., β= 110.55(3). γ = 97.61(5)°, and Z=l for 2; a = 7.0281(4), b = 7.7176(6), c = 8.6978(7)Å, a = 68.103(7), β = 68.526(5), γ = 62.550(6)°, and Z=1 for 3; a = 9.1807(4), b = 6.3334(3), c = 6.8871(3)Å, a= 108.213(4), β = 99.433(4), γ= 105.190(4)°, and Z= 1 for 4. The arrangements around the metal ions are trans-octahedra with two pyridyl nitrogens and two aqua oxygens in the equatorial positions and two aqua oxygens in the axial positions, although the Cu(II) complexes show a larger Jahn-Teller distortion. 相似文献
11.
12.
13.
Klyueva M. E. Lomova T. N. Suslova E. E. Semeikin A. S. 《Theoretical and Experimental Chemistry》2003,39(5):309-315
We have synthesized complexes of copper(II) with octaethyl-, 5-phenyl octaethyl-, 5,15-diphenyl octaethyl-, and 5,10,15,20-tetraphenyl octaethylporphyrins. We have studied their dissociation kinetics in mixed solvents AcOH – H2SO4 at temperatures of 298 K to 343 K. We have determined the complete kinetic equations for dissociation of copper porphyrins for different compositions of the binary solvent AcOH – H2SO4. We provide a rational basis for electronic and steric effects on the stability of copper(II) octaethylporphyrin upon meso-phenyl substitution as a function of the degree of substitution. 相似文献
14.
Madhu N. T. Radhakrishnan P. K. Grunert M. Weinberger P. Linert W. 《Journal of Thermal Analysis and Calorimetry》2004,76(3):813-821
The phenomenological, kinetic and mechanistic aspects of thermal decomposition of perchlorate, nitrate, chloride, bromide
and iodide complexes of cobalt(II) with the Schiff base 1,2-bis(imino-4'-antipyrinyl)ethane (GA) have been studied by TG and
DTG analyses. The kinetic parameters like the activation energy, pre-exponential factor and entropy of activation were calculated.
The decomposition reactions follow 'random nucleation with one nucleus on each particle - Mampel model'.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
15.
《Journal of Coordination Chemistry》2012,65(2):129-138
Abstract The ESR spectra of a series of copper(II) alkanoates with the empirical formula Cu2 X 4 (X = heptanoate, octanoate, nonanoate, decanoate, dodecanoate), and their pyridine adducts have been measured over the temperature range 300K to 100K. The spectra of nonadduct copper(II) alkanoates exhibit extreme temperature dependent behavior; the room temperature spectra show a single broad line centered on g ≈ 2.1, however as the temperature is lowered triplet state features appear. The corresponding pyridine adducts give typical triplet state spectra at all temperatures. This temperature behavior can be interpreted in terms of interdimer interactions in copper(II) alkanoates having the polymeric structure. The observed resonance lines are used to calculate the zero-field splitting parameters D and E. The spin Hamiltonian and zero-field splitting parameters are used to estimate the exchange parameter J. The values of /2J/ for the compounds investigated are in the range of 300–400cm?1 and suggest that the copper(II) ions are strongly antiferromagnetically coupled. 相似文献
16.
17.
《Journal of Coordination Chemistry》2012,65(4):357-365
Abstract The addition of nitromethane anion to the C=N group of polyalkyl-1,4,8,11-tetraazacyclotetradeca-4, 11-dienenickel(II) diperchlorate gave Ni(II) complexes of new macrocyclic ligands containing a pendant 5-nitromethyl group. Variable temperature (80–290 K) magnetic susceptibilities were determined for the paramagnetic monoperchlorates and the diamagnetic square-planar diperchlorates. Conformations of the nitromethyl groups in the macrocyclic ligands were established on the basis of 1H NMR evidence. 相似文献
18.
The kinetics of substitution of chloride ions for ethylendiamine in a bis-ethylenediamine complex of palladium(II) is studied in solutions with pH 0.3–2.0 and the ionic strength of 0.11–1.0 M by measuring the transients of limiting diffusion currents of the electroreduction of palladium(II) ethylenediamine complexes on a rotating disk electrode. The first reaction orders in hydrogen and chloride ions are found at the ionic strength of 1 M (NaClO4). The activation energy of the homogeneous reaction under study is determined from the temperature dependence of its rate constant. The mechanism of substitution of chloride ions for ethylenediamine is discussed. 相似文献
19.
20.
《Journal of Coordination Chemistry》2012,65(3-4):267-284
Abstract Infrared spectra of the coordination compounds [MG2(py)2], M(II)=Co, Ni, Cu and Zn; G=glycolato, py=pyridine, have been fully assigned by means of py and py-d 5 and glycolato α—OH and α—OD (G-d) labelling as well as metal ion substitution in the 4000–70cm?1 region. The crystal structure of the Ni(II) compound is presented and the spectra of the compounds are discussed on the basis of their structure and their bonding to the glycolato and pyridine ligands. Vibrational frequencies obtained for the Ni(II) compound are compared to those obtained by calculations carried out using the Gaussian 94 program package. 相似文献