Chemical Bonding in Thermodynamically Labile Oxyanion Crystals

Crystal valence density and difference density distributions were calculated for NaNO₂, NaNO₃, KClO₃, and NaClO₄ using local density functional theory. Hybridization of the oxygen states is enhanced in compounds with lower symmetry, leading to the formation of oxygen chains in the lattice. Interaction between the oxygen and anion's central atom sublattices gives rise to electron charge maxima in the middle of the A—O bonds and to two terminal oxygen maxima. The complex character of the intraanion electron transfer and the charge transfer between the nonequivalent oxygen sublattices make these compounds susceptible to external energy effects that lead to their solidstate decomposition.     

New N-nitrosoamines. 2. Transformations of tetrahydro-1,3-oxazines into nitrates of N-nitrosoamino alcohols

The reactions of HNO₃ with tetrahydro-1,3-oxazines 1a—c produced by aminomethylation of diketopiperazine, isatin, and succinimide, respectively, afforded nitrates of amino alcohols [RCH₂NH₂(CH₂)₃ONO₂]⁺NO₃ ^– (4a—c) whose subsequent N-nitrosation (NaNO₂, AcOH) gave nitrates of N-nitrosoamino alcohols RCH₂N(NO)(CH₂)₃ONO₂ (5a—c). The structures of compound 5b,c were established by X-ray diffraction analysis.     

中稀土硝酸盐与甘氨酸固体配合物的研究

文中以１：４摩尔比在水中制得了中稀土硝酸盐与甘氨酸固体配合物，经过化学分析，元素分析、红外光谱、热谱及Ｘ光粉衍射等方法，确定配合物通式 为Ｌｎ（Ｎｏ３）３（Ｇｌｙ）４（Ｌｎ＝Ｓｍ．Ｅｕ，Ｇｄ．Ｔｂ．Ｄｙ．Ｅｒ；Ｇｌｙ＝Ｇｌｙｃｉｎｅ），并对所制配合物某些物理性质及化学性质进行了讨论。     

Group separation of organic nitrates on a new nitric acid ester NP-LC stationary phase

Summary The synthesis of a nitric acid ester NP-LC stationary phase (organonitrate phase), by nitrating a commercial polyol phase (Serva, Polyol Si 100, 5 μm) with mixed sulfuric-and nitric acid, is reported. The nitric acid ester bond is quite stable towards hydrolysis. To examine its possible use as a stationary phase for the group separation of alkyl nitrates, several bifunctional polar alkyl nitrates (di-nitrates, hydroxy-nitrates, keto-nitrates) have been synthesized. In order to simplify their names a new abbreviating nomenclature for multifunctional organic nitrates is presented. With our new stationary phase it is possible to separate mono-, di-, and hydroxy-nitrates as groups completely, a major advantage in sample preparation in the chemistry of smog formation. However a co-elution of di- and keto-nitrates is observed. A distinction of the latter two organonitrate groups is possible by gas chromatography-mass spectrometric detection (MSD). Apart from the fragment ion NO₂ ⁺ (m/z=46 amu), which is nearly specific for alkyl nitrates, aliphatic di- and keto-nitrates show different characteristic fragment ions.     

A theoretical study of vibrational spectra of tetranitrate-methyl-β-D-glucopyranoside and 2,3-di-O-nitro-methyl-β-D-glucopyranoside

Coupled calculations were carried out of normal vibration frequencies from the point of view of the valence-force field scheme and of absolute IR band intensities by the CNDO/2 method for the tetranitrate-methyl-β-D-glucopyranoside molecule. A good agreement was achieved with the experiments. Normal coordinate analysis was made for 2,3-di-O-nitro-methyl-β-D-glucopyranoside molecule with force constants obtained for the tetra-nitrate-methyl-β-D-glucopyranoside. Before proceeding to the calculation of the spectra of such complex molecules of nitrates of monosaccharides, a complete experimental and theoretical investigation was performed of the vibrational spectra of methylnitrate, which made it possible to determine the deficit of force constants for the calculations of the spectra of nitrosubstituted glucopyranosides. Detailed interpretations of the observable IR spectra of both the nitro-glucopyranosides compounds considered are given. The absorption spectra sensitivity to the spot of the nitrate group localization was discovered. Special attention was focused on analyzing the spectra of nitrates of saccharides for the characteristic split of the band due to the asymmetric stretching vibrations of the ONO₂ groups in the region of 1600–1700 cm⁻¹.     

Die chemische Zersetzung von Seltenerd-Nitraten: Eine neue Methode zur Anreicherung schwerer Yttererdnitrate im kg-Maßstab

Summary On addition of oxidizable organic substances to molten rare earth nitrates reaction takes place with evolution of nitric oxides and formation of basic nitrates, the two-step hydrolysis of which results in effective enrichment of heavy yttrium earths (YE) from rare earth mixtures in kg-quantities. Using methanol as reducing agent the reaction takes place at 160°C, much lower than using the method of purely thermal decomposition. In both methods after the first hydrolysis step a productYE(OH)_1.5(NO₃)_1.5·H₂O can be isolated.

     

Conductance and Thermodynamic Study of the Interaction of Mixed Oxygen–N2–Donor Macrocycles with Ag(I), Ni(II) and Fe(III) in Acetonitrile Solutions

The thermodynamic stabilities of Ag⁺, Ni²⁺ and Fe³⁺with diaza-crown ethers have been determinedconductometrically in acetonitrile at temperatures of 293, 298, 303 and 308 K.Both the size of the macrocyclic ring and the hard and soft acidand base (HSAB) character of the metal ions influence the relative stabilities of the complexes. For the metal ions with diazacrown ethers the values of log K_f for the 1 : 1 complexesfollow the order Ag⁺ > Ni²⁺ > Fe³⁺in accordance with Pearson's principle of HSAB character. The enthalpy and entropy of complexation were determined from the temperature dependence of the complexationconstants. The complexation process is entropy governed.     

电喷雾多级串联质谱法研究碱金属硝酸盐和亚硝酸盐簇合物离子的裂解行为

在正常毛细管温度(200 ℃)下,利用电喷雾质谱(ESI-MS)研究了NaNO3、KNO3、NaNO2和KNO2形成的新型簇合物离子,采用电喷雾多级串联质谱(ESI-MSn)研究了簇合物离子裂解行为.实验结果表明: NaNO3和KNO3溶液产生的簇合物离子及这些离子的裂解方式相似;NaNO2溶液产生的簇合物离子比NaNO3和KNO3溶液产生的复杂;KNO2溶液产生了含有Na+离子的簇合物离子,通过分析KNO2簇合物离子的裂解行为证明了Na+与NO-2的亲合势大于K+.此外,还研究了离子源金属毛细管温度和溶液浓度对簇合物离子形成的影响.     

Bulk viscosity and relaxation frequencies in molten alkali nitrates

Measurements of ultrasonic absorption and speed were carried out in molten LiNO₃, NaNO₃, RbNO₃, KNO₃ and CsNO₃ by the pulse method. The results indicate that the bulk viscosity is due to a structural mechanism. The hole theory provides a model for this mechanism. Comparing the results of measurements at ultrasonic and Brillouin frequencies, the values of relaxation frequencies were deduced. These results were compared to those provided by the hole theory.     

Ligand Exchange and Nature of Luminescence Centers in the Crystals of Uranyl Nitrates and Perchlorates

We obtained complexes of uranyl nitrates and uranyl perchlorates with neutral ligands in crystalline and amorphous states and also with variable composition (as regards both water and the quantity of acid ligands entering into the first coordination sphere of UO₂ ²⁺). We studied their luminescence spectra at T = 77 K. Correlation between the frequencies of electronic and vibronic transitions and the donor numbers of neutral ligands has been established. The possible ways of replacing neutral ligands in the first coordination sphere of UO₂ ²⁺ have been analyzed as well as the composition and structure of the complex systems formed in this case.