Complex salts [Pd(NH3)4](ReO4)2 and [Pd(NH3)4](MnO4)2: Synthesis, structure, and thermal properties

Complex salts, i.e., tetraamminepalladium perrhenate (I) and permanganate (II), are synthesized and studied by physicochemical methods. Their crystal structures are determined and thermal analysis is performed. The products formed in thermolysis of I and II carried out in the atmosphere of helium and hydrogen are studied. The Pd_0.33Re_0.67 solid solution based on Re is shown to form under particular temperature conditions in the atmosphere of hydrogen.     

原子和离子的f^k与g^k的计算方法

本文给出了原子和离子能量表达式中的库仑积分与交换积系数ｆ＾ｋ，ｇ＾ｋ的计算方法，同时给出了计算中所涉及的Ｒａｃａｈ系数，Ｕ＾（＾Ｋ＾），Ｖ＾（＾Ｋ＾）和Ｃ＾（＾Ｋ＾）矩阵等光谱参量的计算方法，用ＦＯＲＴＲＡＮⅣ语言编写了关于ｆ＾ｋ和ｇ＾ｋ的计算机程序，只要输入与光谱项有关的量子数，即可迅速得到相应的ｋ＾ｆ，ｇ＾ｋ值，避免了烦琐的人工推算。     

Cauchy problem of the generalized double dispersion equation

In this paper, the existence and the uniqueness of the global solution for the Cauchy problem of the generalized double dispersion equation are proved. The blow-up of the solution for the Cauchy problem of the generalized double dispersion equation is discussed by the concavity method under some conditions.     

Plasma flow accompanied by blowing and pumping of plasma across electrodes

The article discusses plane stationary slowly varying flows of a nonviscous plasma with good conductivity in a channel in a transverse magnetic field; the flows are accompanied by blowing in and pumping plasma across solid metallic electrodes. The Hall effect is taken into consideration. It is shown that the potential jump near the anode, which appears in an accelerated plasma flow in an ordinary channel with solid electrodes, can be eliminated in flows accompanied by blowing in (pumping) of plasma. It is also shown that flows are possible in which the velocity, density, and the transverse electric field increase in the direction of the accelerator cathode.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 6, pp. 26–34, November–December, 1970.     

Regioselectivity in the amination of azines: Reaction of pyrazine derivatives with <Emphasis Type="Italic">O</Emphasis>-mesitylenesulfonylhydroxylamine

Treatment of 2-X-substituted pyrazines [X = H, Me, Et, Pr, i-Pr, t-Bu, MeCH(OH), H₂N, AcNH] with O-mesitylenesulfonylhydroxylamine gave the corresponding 2-X- and 3-X-(1-amino)pyrazin-1-ium mesitylenesulfonates. 2-Alkylpyrazines (X = Me, Et, Pr, i-Pr) displayed a correlation between the logarithms of the concentration ratio of 2- and 3-substituted cations and substituent steric constants. Wider series of substituted pyrazines [X = H, Me, Et, Pr, i-Pr, MeCH(OH), H₂N, AcNH] conformed to a multiparameter correlation between the logarithms of the concentration ratio of 2- and 3-substituted cations, on the one hand, and substituent constants σ_I, σ_R^o, and E _s^o, on the other. The obtained data on the regioselectivity of amination of pyrazines were interpreted in terms of DFT/PBE/3Z quantum-chemical calculations.     

Structure-kinetics relations holding in the amination of six-membered nitrogen-containing heterocyclic compounds

Relative rates of the amination of 3-X- and 4-X-substituted pyridines (X = H, 3-Me, 4-Me, 3-F₃C, 3-CN, 4-CN, 3-Cl, 3-Br, 4-MeO, 4-Me₂N), pyrazine, quinoline, isoquinoline, 2,2′- and 4,4′-bipyridines, and 1,10-phenanthroline with O-mesitylenesulfonylhydroxylamine were estimated by NMR spectroscopy. Correlations were found between logarithms of the relative amination rate constants and substituent constants σ or σ_I and σ_R for X-substituted pyridines. A wide series of nitrogen-containing heterocyclic compounds turned out to fit correlations between logarithms of the relative amination rate constants, on the one hand, and relative stabilities of N-aminoazinium cations, energies of activation of the amination process, and gas-phase proton affinities, calculated by the DFT/PBE/3z and DFT/B3LYP/L2 methods, on the other.     

Behavior of 9-cyclopropyl-10,10-dimethyl-9,10-dihydrophenanthren-9-ol in acid medium: Opening of the cyclopropane ring

According to the NMR data, opening of the cyclopropane ring in carbocations derived from 9-cyclopropyl-10,10-dimethyl-9,10-dihydrophenanthren-9-ol in acid medium follows two pathways, depending on the acidity. The first pathway is protonation of the cyclopropyl group; it occurs in strongly acidic medium (HSO₃F-SbF₅-SO₂ClF-CD₂Cl₂). The second pathway involves cyclopropyl-carbinyl rearrangement; it is typical of less acidic medium.     

Modeling molecular acidity with electronic properties and Hammett constants for substituted benzoic acids

Molecular acidity is an important physiochemical property essential in many fields of molecular studies, but an efficient and reliable computational approach to make accurate predictions is still missing. In this work, based on our previous studies to use gas phase electronic properties such as molecular electrostatic potential and valence natural atomic orbitals of the acidic atom and leaving proton, we demonstrate here that different approaches can be employed to tackle this problem. To that end, we employ 196 singly, doubly, and triply substituted benzoic acids for the study. We show that two different approaches are possible, one focusing on the carboxyl group through its localized electronic properties and the other on the substituting groups via Hammett constants and their additivity rule. Our present results clearly exhibit that with the linear models built from the singly substituted species, one can accurately predict the pK(a) values for the doubly and triply substituted species with both of these two approaches. The predictions from these approaches are consistent with each other and agree well with the experimental data. These intrinsically different approaches are the two manifestations of the same molecular acidity property, both valid and complementary to each other.