共查询到20条相似文献,搜索用时 0 毫秒
1.
Non-empirical LCAO MO SCF calculations are reported on cross sections through the C2H4Cl+ system and comparisons are drawn with the C2H5+ and C2H4F+ systems. Barriers to rotation in the classical 1- and 2-substituted ethyl cations have been computed and an investigation made of the bridged chloronium and fluoronium ions. The results suggest that the relative stabilities of bridged ions with respect to the corresponding classical 2-substituted ethyl cations increase in the order H < F < Cl. The results are discussed in terms of available experimental data and consideration given to correlation and solvation energy effects. 相似文献
2.
3.
E. Vessally N. Chalyavi A. Rezaei M. Nikoorazm 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2007,81(11):1820-1824
The electronic and thermal energy differences, ΔE(t-s); enthalpy differences, ΔH(t-s); and free energy differences between the singlet and triplet states, ΔG(t-s), were calculated for C6H6C, C6H6Si, C6H6Ge, C6H6Sn, and C6H6Pb at the B3LYP/6-311++G (3df, 2p) level. The singlet-triplet splitting, G
s-t, of C6H6C, C6H6Si, C6H6Ge, C6H6Sn, and C6H6Pb generally increased from C6H6C toward C6H6Pb. The most stable tautomers and conformers were suggested for the singlet and triplet states of C6H6M (M = C, Si, Ge, Sn and Pb). The geometrical parameters were calculated and discussed.
The text was submitted by the authors in English. 相似文献
4.
5.
6.
The novel copper(Ⅱ) complex with salicylaldehyde benzoylhydrazone and pyridine ligands, Cu(C14H10N2O2)(C5H5N), has been synthesized and characterized by elemental analysis, IR and thermal analysis. The crystal structure of the title complex has been determined by single crystal X-ray diffraction techniques. The crystal belongs to monoclinic with space group P21/c. The cell parameters are: a=1.6362(9)nm, b=1.7140(9)nm, c=1.2255(7)nm, β=105.168(9)°, V=3.317(3)nm3, Z=8, Dc=1.525g·cm-3, μ(MoKα)=1.334mm-1, F(000)=1560. The structure was refined to final R1=0.0376, wR2=0.0909. The copper(Ⅱ) ion lies in a dis-torted square-planar environment composed of two oxygen atoms, one nitrogen atom of tridentate acyhydrazone Schiff base ligand and one nitrogen atom of the pyridine ligand. CCDC: 193111. 相似文献
7.
Chand, A., McQuillan, A.R. and Fenby, D.V., 1979. Thermodynamic study of systems with lower critical solution temperatures: H2O + (C2H5)3N, D2O + (C2H5)3N. Fluid Phase Equilibria, 2: 263–274.Molar excess enthalpies and molar excess volumes are reported for the systems H2O + (C2H5)3N and D2O + (C2H5)3N at temperatures below and above their lower critical solution temperatures. The molar excess enthalpies are slightly less exothermic for the D2O system. The molar excess volumes of the H2O and D2O systems are within experimental error of one another. Compositions of conjugate solutions estimated from the calorimetric and volumetric measurements agree with those obtained from published liquid—liquid phase diagrams. 相似文献
8.
Twenty-two isomers/conformers of C3H6S+√ radical cations have been identified and their heats of formation (ΔHf) at 0 and 298 K have been calculated using the Gaussian-3 (G3) method. Seven of these isomers are known and their ΔHf data are available in the literature for comparison. The least energy isomer is found to be the thioacetone radical cation (4+) with C2v symmetry. In contrast, the least energy C3H6O+√ isomer is the 1-propen-2-ol radical cation. The G3 ΔHf298 of 4+ is calculated to be 859.4 kJ mol−1, ca. 38 kJ mol−1 higher than the literature value, ≤821 kJ mol−1. For allyl mercaptan radical cation (7+), the G3 ΔHf298 is calculated to be 927.8 kJ mol−1, also not in good agreement with the experimental estimate, 956 kJ mol−1. Upon examining the experimental data and carrying out further calculations, it is shown that the G3 ΔHf298 values for 4+ and 7+ should be more reliable than the compiled values. For the five remaining cations with available experimental thermal data, the agreement between the experimental and G3 results ranges from fair to excellent.
Cation CH3CHSCH2+√ (10+) has the least energy among the eleven distonic radical cations identified. Their ΔHf298 values range from 918 to 1151 kJ mol−1. Nevertheless, only one of them, CH2=SCH2CH2+√ (12+), has been observed. Its G3 ΔHf298 value is 980.9 kJ mol−1, in fair agreement with the experimental result, 990 kJ mol−1.
A couple of reactions involving C3H6S+√ isomers CH2=SCH2CH2+√ (12+) and trimethylene sulfide radical cation (13+) have also been studied with the G3 method and the results are consistent with experimental findings. 相似文献
9.
1-Allyl-4-aminopyridinium chloride reacts with Cu(NO3)2 · 3H2O in an ethanolic solution under the conditions of ac electrochemical synthesis at copper electrodes to form crystals of compound
[(NH2C5H4N(C3H5))2Cu3Cl3(NO3)2] (I). The crystals of compound I are monoclinic: space group P21/c, Z = 4, a = 25.770(7), b = 7.230(4), c = 12.505(5) ?, β = 92.58(3)°, V = 2328(2) ?3. The direct interaction of 1-allylquinolinium nitrate with Cu(NO3)2 · 3H2O in a methanolic solution in the presence of metallic copper yields crystals of compound [C9H7N(C3H5)Cu(NO3)2] (II). The crystals of compound II are triclinic: space group P
, a = 6.756(3), b = 8.391(4), c = 12.489(5) ?, α = 77.18(3)°, β = 89.48(4)°, γ = 73.32(3)°, V = 662.0(5) ?3. The structure of compound I is built of infinite linear anions: polymeric fragments {(NH2C5H4N(C3H5))2Cu3Cl3(NO3)2}
n
. Each of two copper atoms (Cu(1) and Cu(2)) π-coordinates the C=C bonds of the allyl groups of the 1-allyl-4-aminopyridinium
cations, the oxygen atom of the nitrate ions, and two chlorine atoms. The third copper atom Cu(3) is linearly linked with
two chlorine atoms. Particular polymeric fragments are additionally joined by the N-H…O, C-H…O, C-H…Cl hydrogen bonds. The
crystal structure of compound II is built-up of the isolated L2Cu2(NO3)4 fragments (L is the 1-allylquinolinium cation). The metal atom is localized in the trigonal pyramidal coordination environment
of three oxygen atoms of the nitrate ions and of the C=C bond of the allyl group of the cation. The particular L2Cu2(NO3)4 fragments are additionally joined by the C-H…O hydrogen bonds.
Original Russian Text ? A.V. Pavlyuk, T. Lis, M.G. Mys’kiv, 2009, published in Koordinatsionnaya Khimiya, 2009, Vol. 35, No.
6, pp. 458–462. 相似文献
10.
Density functional theory (DFT) calculations show that the C2-fragmentation of C70 destroys 4 of 37 original rings and generates 3 new rings, leading to 8 possible isomers. Each of those isomers contains a larger ring (7- or 8-member ring) with or without 4-member ring(s) besides 5- and 6-member rings. The most stable isomer consists of thirteen 5-member, twenty-two 6-member, and a 7-member rings without 4- and 8-member rings. The C2-fragmentation energies (10.7–13.3 eV) of C70 depend on resulted isomer-structures. Furthermore, the equilibrium fraction of the most stable isomer in the total isomers is 99.1%, 94.8%, and 94.0% at temperatures of 900, 1400, and 2000 K, respectively. 相似文献
11.
The mass spectra of metastable molecular and fragment ions demonstrate that the loss of CH3. from [1-methylcyclobutanol].+ leads competitively to three different ions: = protonated cyclobutanone; = [n-C3H7CO]+ and = protonated methylvinylketone. 相似文献
12.
13.
设计合成了两种阴离子功能化离子液体抗氧化剂([MI][C6H5COO]、[Ch][C6H5COO]),采用核磁共振氢谱、傅里叶红外光谱对其结构进行了表征,并研究了两种离子液体抗氧化剂对小桐子生物柴油抗氧化性、铜片腐蚀性和油溶性能的影响。结果表明,离子液体抗氧化剂可有效提高生物柴油氧化稳定性,在添加量为0.3‰时,[MI][C6H5COO]的小桐子生物柴油诱导期提高了238%,超过了中国国家标准(6 h),[Ch][C6H5COO]的小桐子生物柴油诱导期提高了141%,未达到中国国家标准。进一步研究了两种离子液体抗氧化剂的油溶性,油溶性能从大到小的顺序为[MI][C6H5COO] > [Ch][C6H5COO] > GA(合成离子液体抗氧化剂的原料)。实验表明,合成的两种离子液体抗氧化剂中含有亲油阳离子的[MI][C6H5COO]综合性能明显优于含有亲水阳离子的[Ch][C6H5COO]。 相似文献
14.
Paz Vaqueiro 《Journal of solid state chemistry》2006,179(1):302-307
Two new main group metal sulphides, [C10N4H26]0.5[InS2] (1) and [C10N4H26]0.5[GaS2] (2) have been prepared solvothermally in the presence of 1,4-bis(3-aminopropyl)piperazine and their crystal structures determined by single-crystal X-ray diffraction. Both compounds are isostructural and crystallise in the monoclinic space group P21/n (Z=4), with a=6.5628(5), b=11.2008(9), c=12.6611(9) Å and β=94.410(4)° (wR=0.035) for compound (1) and a=6.1094(5), b=11.2469(9), c=12.7064(10) Å and β=94.313(4)° (wR=0.021) for compound (2). The structure of [C10N4H26]0.5[MS2] (M=In,Ga) consists of one-dimensional [MS2]− chains which run parallel to the crystallographic a axis and are separated by diprotonated amine molecules. These materials represent the first example of solvothermally prepared one-dimensional gallium and indium sulphides. 相似文献
15.
B. Levy 《Chemical physics letters》1973,18(1):59-62
The results of several MC SCF calculations on CH4, C2H4 and C2H6 with minimun bases of Slater type AO's are reported. The computing method is a quadratically convergent process. Better final energies are obtained if localized MO's are used. 相似文献
16.
17.
A novel nickel(Ⅱ) complex with 2,4-dihydroxybenzalidene benzoylhydrazone and pyridine ligands, Ni(C14H10N2O3)(C5H5N), has been synthesized and characterized by elemental analysis and IR. The crystal structure of the title complex has been determined by single crystal X-ray diffraction techniques. The crystal belongs to orthorhombic, space group Pbca. The cell parameters are: a=1.580 20(19) nm, b=1.362 18(16) nm, c=1.616 50(19) nm, and V=3.479 5(7) nm3, Z=8, Dc=1.497 Mg·m-3, μ(MoKα)=1.139 mm-1, F(000)=1 616, R=0.032 9 and wR=0.077 0 for 2 772 observed reflections (I>2σ(I)) out of 3810 unique ones. The nickel(Ⅱ) ion lies in a distorted square-planar environment composed of two oxygen atoms, one nitrogen atom of tridentate acyhydrazone schiff base ligand and one nitrogen atom of the pyridine ligand. The analysis of the crystal structure indicates that the complex has a one-dimensional chain structure, which is formed by intermolecular hydrogen bonds. CCDC: 244668. 相似文献
18.
High pressure vapour-liquid equilibrium data for the C2H6 + N2, C2H4 + N2, C3H8 + N2, and C3H6 + N2 systems are presented. The data are obtained isothermally in the range from 200 K to 290 K. For each point of data, temperature, pressure and liquid and vapour phase mole fractions are measured.Values for the vapour phase mole fractions are calculated from the obtained pressure, temperature and liquid phase mole fractions. The calculated values are compared with the experimental results, and it is found that the average mean deviation between calculated and experimental mole fractions is less than 0.009 for the systems considered in this work. 相似文献
19.
The title coordination compound with N-substituted-salicyl Schiff ligand, Cu(C15H12N2O3)(C5H5N), has been synthesized. The coordination compound crystallizes in orthorhombic system, space group Pbca with a=2.037 62(7) nm, b=0.698 45(2)nm, c=2.508 76(9)nm, V=3.570 4(2) nm3, Z=8, F(000)=1 688, Dc=1.529 g·cm-3, Mr=410.91, μ=1.250 mm-1, R=0.031 3 and wR=0.077 0. In the coordination compound, one phenolate oxygen, one carbonyl oxygen and one hydrazine nitrogen atom from the dianionic ligand N-salicylaldehyde-N′-(4-methoxybenzoyl) hydrazone and one pyridine nitrogen atom coordinate to Cu(Ⅱ) ion, forming a distorted square plane. CCDC: 218182. 相似文献
20.
A novel binuclear copper complex of [Cu(C14H8O3)(C9H7N)(C2H5OH)]2 was synthesized and characterized by elemental analysis, IR, thermal analysis and X-ray single crystal diffraction. The title complex crystallizes in monoclinic system, space group
P21/c with a=1.381 7(3) nm, b=1.184 3(2) nm, c=1.332 5(3) nm, β=104.77(3)°. Each copper(II) atom is five-coordinated by three oxygen atoms from two different 9-hydroxy-fluorene-9-carboxylate ligands, one quinoline nitrogen atom and one ethanol oxygen atom, forming a distorted square-pyramidal coordination geometry. Two copper(II) atoms are linked by two 9-hydroxy-fluorene-9-carboxylate ligands into a dimmer structure with the Cu…Cu separation being 0.298 39(8) nm. The dinuclear motifs are further linked into a two-dimensional supramolecular layer via hydrogen bonds interactions. CCDC: 272850. 相似文献