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1.
Crystals of [Cu(Eddp)·(HgCl2)3]n (monoclinic, a = 9.7547(7) Å, b = 18.3716(12) Å, c = 11.7811(9) Å, β = 94.828(9)°, Z = 4, space group P21/n) are made of infinite sheets involving dimeric complexes [Cu2(Eddp)2] interacting with quasi-molecules of HgCl2 (Hg-Cl 2.29-2.36 Å). In the dimers, copper atoms are squarely surrounded by two N atoms and two O atoms of the ethylendiamine-N,N′-di(3-propionate) anion, and atom from a neighboring Eddp ion in the apical position; the second apical position is occupied by a Cl atom of one of HgCl2 molecules. Weak Hg-Cl interactions (2.98-3.07 Å) join the molecules of HgCl2 in almost planar centrosymmetrical Hg6Cl12 hexamers, and further (Hg-Cl 3.168(3) Å, 3.250(2) Å) in infinite chains of the hexamers. Finally, the dimeric copper complexes are linked to six Hg atoms of four adjacent hexamers by virtue of their oxygen atoms (Hg-O 2.322(8), 2.609(6) Å, 2.730(5) Å).  相似文献   

2.
The CoLX2 complexes were obtained by the reaction of N,N-dimethyl-N′,N′-dimethylthio-carbamoylsulfenamide (L) with CoX2 (X = Cl, Br, I, NCS). The complexes were investigated by elemental and X-ray analysis, IR, 1H NMR, and electron spectroscopy, conductometry, magnetochemistry, thermogravimetry. It is found that these compounds are high-spin complexes of pseudotetraedral structure with bidentate coordination of L through the thione sulfur atom and sulfenamide nitrogen atom.  相似文献   

3.
We have applied various theoretical methods to gain detailed insights into the isomers as well as the transition states (TSs) along the corresponding reaction pathways for RSNO (R=H, C n H2n+1 n ≤ 4). On the basis of G2 and G2MP2 results, the relative order of stability for R=H is estimated to be trans-HSNO > cis-HSNO > HNSO > cis-HONS trans-HONS, while it is cis-CH3SNO trans-CH3SNO > CH3NSO > trans-CH3ONS > cis-CH3ONS for R=CH3. A similar trend is also obtained from the B3P86 method with considerably less computing effort if the nearly isoenergetic isomers cis-HONS and trans-HONS are ignored. Based on the results of B3P86, cis-RSNO is more stable than trans-RSNO when R=H is replaced by alkyl groups except for R=t-Bu. Natural bond orbital analyses allow us to explore whether the high reactivity of S-nitrosothiols is due to the strong negative hyperconjugation (). The mesomeric effect of S-nitrosothiols, although non-negligible, does not cause the breakage of N–O bond due to the compensation of columbic attraction between N and O.Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users.  相似文献   

4.
Protolytic equilibria and complexation of N-(2-carboxyethyl)anthranilic acid (H2CEAnt) with copper(II) ions in aqueous solutions were studied by UV spectroscopy and pH potentiometry. The H2CEAnt compound has no zwitterionic structure, and the protons are localized on the carboxy groups. The acid ionization constants of H3CEAnt+ (T = 25 °C, I = 0.1 M KNO3) are pK 0 = 1.3±0.2 (=NH2 +), pK 1 = 3.88±0.02 (Alk-COOH), and pK 2 = 5.28±0.02 (Ar-COOH). The model of complexation of H2CEAnt with copper(II) ions involves two deprotonated complexes [Cu(CEAnt)] and [Cu(CEAnt)2]2− (logβ = 6.31±0.04 and 8.0±0.2, respectively). The [Cu(CEAnt)(H2O)]⋅H2O complex was synthesized by the reaction of H2CEAnt with (CuOH)2CO3, and its structure was established by X-ray diffraction. The coordination polyhedron of Cu is intermediate between the tetragonal pyramid and trigonal bipyramid. The CEAnt2− ligand serves as a tetradentate chelating bridging ligand (Cu-O, 1.944(3) and 1.950(3) Å; Cu-O', 2.195(4) Å; Cu-N, 2.016(5) Å), and the fifth position of the polyhedron is occupied by a water molecule (Cu-Ow, 1.976(4) Å). Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1518–1523, July, 2005.  相似文献   

5.
Two opposite configuration (R/S) of chiral complexes (C8H11N)2·CuCl2 were obtained from the reaction of chiral d(+)/l(−)-α-ethylphenyl amine with copper chloride (II) in dry ethanol. The crystal structures of 1a and 1b were characterized by IR, elemental analysis and X-ray crystallography.  相似文献   

6.
The geometrical structure, binding energy, and vibrational spectra of small clusters of nitrosyl hydride (HNO) and water molecules, HNO(H2O) n , where (n = 1–4), have been investigated at the MP2 level of theory, using 6-311++G(2d,2p) basis set. We located three dimers, six trimers, nine tetramers, and three pentamers at the MP2/6-311++G(2d,2p) computational level. Particular attention is given to existence and magnitude of NH···O blue-shifting hydrogen bonds. Blue shifts of the NH stretching frequency upon complex formation in the ranges between 28 and 151 cm−1 is predicted. Cooperative effect in terms of stabilization energy along with the many-body interaction energies analysis was performed for the studied clusters. The Atoms in Molecules (AIM) theory was also applied to explain the nature of the complexes.  相似文献   

7.
The electron paramagnetic resonance (EPR) parameters (g factors and hyperfine structure constants) for Cu2+ in [Cu(ipt)(dap)H2O] n ?nH2O (ipt is isophthalic acid, dap–1,3-diaminopropane) are theoretically investigated from the high order perturbation formulas of these parameters for a 3d 9 ion in a rhombically elongated octahedron. The ligand orbital and spin-orbit coupling contributions are included from the cluster approach because of strong covalency of the system. The nearly axial anisotropies of the g factors and hyperfine structure constants are correlated to the significant elongation distortion of the five-fold coordinated Cu2+ (in a distorted square pyramidal [CuN2O3] group). Nevertheless, the perpendicular anisotropies arising from the nonequivalent planar ligands are largely concealed by the experimental uncertainties. The theoretical analysis of the EPR behaviours for [Cu(ipt)(dap)H2O] n ?nH2O would be helpful to understand the local structures and properties of this and relevant systems.  相似文献   

8.
The Schiff-base compound N,N′-Bis-(2,5-dimethoxybenzylidene)-1,3-diaminopropan, (2,5-MeO-ba)2pn, is synthesized and characterized by elemental analysis, FT-IR and 1H NMR spectroscopy. The crystal structure of (2,5-MeO-ba)2pn is determined by X-ray single crystal diffraction analysis. The X-ray diffraction analysis at 120 K reveals that (2,5-MeO-ba)2pn crystallizes in the orthorhombic system, Fdd2 space group with a = 29.339(9) Å, b = 29.4073(11) Å, c = 4.4524(2) Å, V = 3840.8(3) Å3, μ = 0.72 mm?1, and Z = 8.  相似文献   

9.
The structures of two isostructural phases of [M(Еn)3](ReO4)2 (M = Ni, Zn; Еn is ethylenediamine) are studied. The crystal structures belong to the triclinic system, but demonstrate a pseudohexagonal packing motif. It is shown that the product of thermal decomposition of [Zn(Еn)3](ReO4)2 (hydrogen atmosphere, 400 °C) is a homogeneous mixture of nanocrystalline zinc and rhenium powders with coherent scattering regions of ~30 nm.  相似文献   

10.
Catalytic aminomethylation of pyrrole and indole with N,N,N′,N′-tetramethylmethanediamine in the presence of 5 mol % of ZrOCl2·8H2O proceeds selectively at the positions 2, 5 of pyrrole and 1, 3 of indole. Carbazole under the same conditions affords 3-formyl-9-aminomethyl derivative. The reaction in the presence of 5 mol % of K2CO3 occurs as monoaminomethylation: for pyrrole at the position 2, for indole at the position 3, and for carbazole at the nitrogen atom of the substrate. Water-soluble 1,1′-(1H-pyrrole-2,5-diyl)bis(N,N-dimethylmethanamine) exhibits a fungistatic activity with respect to phytopathogenic fungi Rhizoctonia solani.  相似文献   

11.
The structure and stability of perlithioannulenes C n Li n (n = 3–6) were examined ab initio [MP2(full)/6-311+G**] and in terms of the density functional theory (B3LYP/6-311+G**). The systems with n = 3, 5, and 6 may be stabilized as planar star-like structures with bridging lithium atoms and hypercoordinate carbon atoms. Star-like structures are the most stable isomers of odd-numbered annulenes (n = 3, 5), while the most stable isomers of even-numbered annulenes (n = 4, 6) have less symmetric nonplanar structures.  相似文献   

12.
The transport and thermal properties of Cs1 − x Rb x H2PO4 in a wide range of compositions were studied. The binary salts Cs1 − x Rb x H2PO4 (x = 0–0.9) contain solid solutions with a structure of CsH2PO4. The binary salts were synthesized by mechanically mixing the starting components and growing crystals by isothermal evaporation from aqueous solutions. The properties of Cs1 − x Rb x H2PO4 salts obtained by different procedures were found to differ considerably. At higher rubidium contents in compounds obtained by mechanical mixing, the superionic transition temperature rose insignificantly, the high-temperature phase conductivity decreased twofold, the low-temperature conductivity increased within the limits of the order of magnitude, and the system of hydrogen bonds was slightly weakened. In Cs1 − x Rb x H2PO4 crystals grown from solutions, the temperature of the superionic transition decreased along with its slowing down, and the low-temperature conductivity increased by more than three orders of magnitude because of the higher contents of residual acid aqueous centers in the structure of the salt. These systems are characterized by increased thermal stability.  相似文献   

13.
Analytical relations through the initial values are derived for the molecular auxiliary functions A α (x) and B n (x), where α =n+ɛ, 0⩽ ɛ < 1 and n=0,1,2,.... These relations are useful in the fast calculation of multicenter molecular integrals over integer and noninteger n Slater type orbitals. It is shown that the formulas obtained are numerically stable for all values of nand x.PACS No: 31.15.+q, 31.20.EjAMS subject classification: 81-V55, 81-V45  相似文献   

14.
Magnetic properties of spinel solid solutions CuCr2–х Sb x Se4 (х = 0–0.5) were measured in the temperature range 5–300 K in a constant (50 Oe and 10 kOe) magnetic field. The results are interpreted in terms of the ionic model suggested earlier for CuCr2Х4 compounds.  相似文献   

15.
The structure of bis(N,N,N′,N′-tetramethylthiophosphoramidoyl)-methylamine 1 has been determined by single-crystal X-ray diffraction. The compound 1 crystallizes in the monoclinic system, with a space group P21/c, a = 11.836(2) Å, b = 11.659(2) Å, c = 12.796(5) Å and β = 95.28(3)°, V = 1758.3(5) Å3 and Z = 4. The X-ray crystallographic data have been assessed by semi-empirical and ab-initio density functional theory and by Hartree–Fock molecular orbital methods. A comparative study of the results of the different methods is given.  相似文献   

16.
The phosphides (Ni1 ? x Co x )2P (0 ≤ x ≤ 0.65) crystallizing in the hexagonal system, space group P \(\bar 6\)2m, were synthesized in two steps starting from the continuous solid solution (Ni1 ? x Co x )3(PO4)2 · 8H2O. The initial phosphates were first completely dehydrated at 800°C and then reduced with hydrogen at 900–1000°C for 1–2 h.  相似文献   

17.
A new lanthanum(III) complex of uracil-1-acetate (UA) and 1,10-phenanthroline (Phen), [La(Phen)(UA)3]n · nH2O, was synthesized and characterized by elemental analysis, IR spectroscopy, XRD powder diffraction, thermal analysis, and X-ray crystallography. The single crystal X-ray analysis shows that the compound is in the monoclinic system, space group P21/c with a = 14.645(6), b = 17.114(7), c = 14.141(6) Å, β = 117.206(6)°, V = 3152(2) Å3, Z = 4, final R 1 = 0.0455 and wR 2 = 0.0909. Each La3+ ion is coordinated by two N atoms from Phen, seven carboxylate oxygen atoms, and one carbonyl oxygen atom from UA, which results in ten-coordinate geometry, LaN2O8. The structural studies indicate that the title compound is two-dimensional coordination polymer, and self-assembly of the compound in the solid state is likely to occur due to N-H…O and O-H…O hydrogen bonds.  相似文献   

18.
A detailed thermodynamic study of the systems LnSe2LnSe1.5 (Ln = La, Nd) was performed by static method of vapour pressure measurement using quartz membrane-gauge manometers within the temperature range 713–1,395 K. The p SeTx dependences obtained in this study have shown that the phase regions in composition intervals studied consist of discrete phases: LnSe1.95 LnSe1.90, LnSe1.85, LnSe1.80 (Ln = La, Nd). The enthalpies and the entropies for the stepwise dissociation process were calculated from the experimental data. The standard enthalpies of formation and the absolute entropies were estimated for the compounds investigated using literature data.  相似文献   

19.
Although LiFePO4 (LFP) is considered to be a potential cathode material for the lithium-ion batteries, its rate performance is significantly restricted by sluggish kinetics of electrons and lithium ions. Several attempts have been made so far to improve the performance of LiFePO4 by reducing the grain size, doping with aliovalent atoms, and coating conductive materials such as carbon or RuO2. We report here synthesis of LFP nanoplates by solvothermal method, tailoring the thickness as well as carbon coverage at surfaces to explore their influence on the storage performance. Due to the fact that Li+ ion diffuses along the b-axis, solvothermal method was aimed to control the thickness of nanoplates across the b-axis. We synthesized several nanoplates with various plate thicknesses along b-axis; among those, nanoplates of LFP with ~30-nm-thick b-axis having thin (2–5 nm) and uniform layer of carbon coating exhibits high storage capacity as well as high rate performances. Thus, a favorable morphology for LiFePO4 has been achieved via solvothermal method for fast insertion/extraction of Li+ as compared to spherical nanoparticles of carbon-coated LFP. Galvanostatic cycling shows a capacity of 164?±?5 mAh g?1 at 0.1 C rate, 100?±?5 mAh g?1 at 10 C rate, and 46?±?5 mAh g?1 at 30 C rate, with excellent capacity retention of up to 50 cycles. Further attempts have been made to synthesize LiMnPO4 (LMP) as well as Li(Fe1???x Mn x )PO4/C (x?=?0.5) nanoplates using solvothermal method. Although LiMnPO4 does not exhibit high storage behavior comparable with that of LiFePO4, the mixed systems have shown an impressive storage performance.  相似文献   

20.
For the first time conditions were determined for the synthesis of Cu x SiO2+x ·nH2O nanostructured layers by consecutive adsorption of copper ammine cations and adagulation of colloidal SiO2 particles and also for the synthesis of xCuS-SiO2·nH2O nanocomposite layers by consecutive surface adsorption of copper cations and HS? anions. These layers were studied by means of UV and visible transmission spectroscopy, X-ray spectral microanalysis, and scanning electron microscopy. Schemes of the surface reactions were constructed on the basis of this experimental material.  相似文献   

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