Metal nitrate driven nitro Hunsdiecker reaction with α,β-unsaturated carboxylic acids under solvent-free conditions

Hunsdiecker reactions with α,β-unsaturated carboxylic acids were conducted under solvent-free conditions in the presence of a few drops of HNO₃ together with a variety of metal nitrates [Mg(NO₃)₂, Sr(NO₃)₂], Al(NO₃)₃, Ca(NO₃)₂, Ni(NO₃)₂, Cd(NO₃)₂, Zn(NO₃)₂, Hg(NO₃)₂, AgNO₃, ZrO(NO₃)₂, UO₂(NO₃)₂, Th(NO₃)₂] or ammonium nitrate. α,β-Unsaturated aromatic carboxylic acids underwent nitro decarboxylation to afford β-nitro styrenes in moderate to good yields, while α,β-unsaturated aliphatic carboxylic acids underwent decarboxylation to yield the corresponding nitro derivatives.     

Thermodynamic properties and solution equilibria of aqueous bivalent transition metal nitrates and magnesium nitrate

Osmotic coefficients for Mn(NO₃)₂, Co(NO₃)₂, Ni(NO₃)₂, Cu(NO₃)₂, Zn(NO₃)₂, and Mg(NO₃)₂ in aqueous solution have been determined by the isopiestic method at 25°C, and activity coefficients have been derived. The results agree with the literature data for Zn(NO₃)₂, while they are significantly different for Co(NO₃)₂, Cu(NO₃)₂, and Mg(NO₃)₂, and those for Mn(NO₃)₂ and Ni(NO₃)₂ are new. The concentration dependence of the osmotic coefficients for the bivalent metal nitrates is similar to that for the trifluoroacetates, while it differs from those for the other salts of the same series of metals. The results are discussed in terms of the inner-sphere and outer-sphere association of ions, auxiliary information being derived from the concentration effects in the visible spectra of the coloured metal nitrates.     

Etude de l’isotherme 25°C du système quasi quaternaire H2O-Zn(NO3)2·6H2O-Cu(NO3)2·3H2O-NH4NO3;I- Isoplèthes 4 masse% NH4NO3, 8 ma

The solid-liquid equilibria of the quasi-quaternary system H₂O-Zn(NO₃)₂·6H₂O-Cu(NO₃)₂·3H₂O-NH₄NO₃ were studied at 25°C by using a synthetic method based on conductivity measurements. Three isoplethic sections has been established at 25°C and the stable solid phases which appear are: NH₄NO₃(IV), Zn(NO₃)₂·6H₂O, anhydrous Cu(NO₃)₂, Cu(NO₃)₂·3H₂O and metastable Cu(NO₃)·2.5H₂O. Neither double salts, nor mixed crystals are observed at these temperatures and composition range.     

Gamma-ray induced decomposition of some divalent and trivalent nitrates

Gamma-ray induced decomposition of some divalent nitrates, viz. Mg(NO₃)₂·6H₂O, Ca(NO₃)₂·4H₂O, Sr(NO₃)₂, Ba(NO₃)₂, Zn(NO₃)₂·6H₂O, Cd(NO₃)₂·4H₂O, Hg(NO₃)₂·2H₂O, Mn(NO₃)₂·4H₂O, Cu(NO₃)₂·3H₂O and trivalent nitrates, viz. Al(NO₃)₃·9H₂O, Fe(NO₃)₃·9H₂O, Cr(NO₃)₃·9H₂O, Y(NO₃)₃·6H₂O, In(NO₃)₃·3H₂O, La(NO₃)₃·6H₂O, Ce(NO₃)₃·6H₂O, Pr(NO₃)₃·6H₂O, Bi(NO₃)₃·5H₂O has been studied in solid state at room temperature. G(NO ₂ ^– ) values (after applying appropriate dose correction) have been found to vary in the range 0.12–3.16 and 0.069–2.15 for divalent and trivalent nitrates respectively. G'-values were calculated by dividing G by the ratio of number of electrons in nitrate ion to the total number of electrons in the nitrate salt. Cation size, its polarizing power, available free space in the crystal lattice and the number and location of water molecules seem to play a dominant role in radiolytic decomposition. For Zn, Sr, In, La and Ce nitrates dose variation studies have been carried out.     

Nitrite and Nitrate Production by NO and NO2 Dissolution in Water Utilizing Plasma Jet Resembling Gas Flow Pattern

This study investigated the reactive dissolution of nitric oxide (NO) and nitrogen dioxide (NO₂) mixtures in deionized water. The dissolution study was carried out in a flat surface type gas–liquid reaction chamber utilizing a gas flow-pattern resembling plasma jets which are often used in biomedical applications. The concentration of NO and NO₂ in the gas mixtures was varied in a broad range by oxidizing up to 800 ppm of nitric oxide in Ar carrier gas with variable amount of ozone. The production of nitrite (NO₂^?) and nitrate (NO₃^?) in the water was proportional to treatment time up to 50 min. The concentration of NO₃^? was a power function of gas phase NO₂ while the concentration of NO₂^? increased approximately linearly with gas phase NO₂. The formation of NO₂^? and NO₃^? could be described by reactions between dissolved NO₂ and NO in the water while the production rate was determined by diffusion-limited mass transport of nitrogen oxides to the bulk of the liquid. At higher NO₂ concentrations, the formation of dinitrogen tetraoxide (N₂O₄) increased the formation rate of NO₂^? and NO₃^?. The identified mass transport limitation by diffusion suggests that convection of water created by the gas jet is insufficient and dissolution of nitrogen oxides can be increased by additional mixing. In respect of practical applications, the ratio of NO₂^? /NO₃^? in water could be varied from 0.8 to 5.3 with treatment time and gas phase NO₂ and NO concentrations.

     

Investigations on the determination of NO2 with galvanic nitrate solid electrolyte cells

Solid electrolyte cells for detecting NO₂ with Ba(NO₃)₂ or Sr(NO₃)₂ partially replaced by γ-Al₂O₃ as solid electrolytes have been studied. The cell tension depends on the NO₂- as well as on the NO-concentration. Investigations of the establishment of the NO₂-NO-O₂-equilibrium by the catalytic effects of the used electrode materials Pt and Au have shown that a decomposition of NO₂ below 400°C cannot be expected.     

Reactions of naphthalene in N2O5?NO3?NO2? air mixtures

The reactions of naphthalene in N₂O₅? NO₃? NO₂? N₂? O₂ reactant mixtures have been investigated over the temperature range 272–297 K at ca. 745 torr total pressure and at 272 K and ca. 65 torr total pressure using long pathlength Fourier transform infrared absorption spectroscopy. 2,3-Dimethyl-2-butene was added to the reactant mixtures at 272 K to rapidly scavenge the NO₃ radicals both initially present in the added N₂O₅ and formed from the thermal decomposition of N₂O₅ during the reactions. The data obtained in the presence and absence of added 2,3-dimethyl-2-butene showed that napthalene undergoes initial reaction with the NO₃ radical to form an NO₃-naphthalene adduct, which either rapidly decomposes back to the reactants (at a rate of ca. 5 × 10⁵ s^?1 at 298 K) or reacts exclusively with NO₂ to form products. When NO₃ radicals, N₂O₅ and NO₂ are in equilibrium, this overall process is kinetically equivalent to reaction of naphthalene with N₂O₅, and previous kinetic and product studies have indeed assumed the reactions of naphthalene and alkyl-substituted naphthalenes in N₂O₅? NO₃? NO₂? air mixtures to be with N₂O₅, and not with NO₃ radicals.     

New Volatile Nitronium Nitratometalates: NO2[Fe(NO3)4] and NO2[Zr(NO3)5] — Synthesis and Crystal Structure

Crystalline NO₂[Fe(NO₃)₄] was obtained by dehydration of a solution of Fe(NO₃)₃ in 100 % HNO₃ and subsequent sublimation. NO₂[Zr(NO₃)₅] was synthesized by reaction of ZrCl₄ with N₂O₅ followed by sublimation in vacuum. X‐ray single crystal structure determination showed both compounds to consist of nitronium cations, NO₂⁺, and nitratometalate anions. N‐O distances in the linear NO₂⁺ cations are in the range of 1.08—1.13Å. In both [Fe(NO₃)₄]⁻ and [Zr(NO₃)₅]⁻ anions, all nitrate groups are coordinated bidentately with average M‐O distances 2.134 and 2.293Å, respectively. Taking into account the position of N atoms around the M atoms, the arrangement of nitrate groups can be described as tetrahedral for the Fe complex and trigonal‐bipyramidal for the Zr complex. There are four shortest N(nitronium)····O(nitrate group) contacts with average distances of 2.705 and 2.726Å in NO₂[Fe(NO₃)₄] and 2.749Å in NO₂[Zr(NO₃)₅]. Nitronium pentanitratohafnate is isotypic to the zirconium complex.     

Reactions of (difluoroamino)trinitromethane with nucleophilic reagents

Reactions of F₂NC(NO₂)₃ with metal fluorides (KF and CsF) in DMF yield a substitution product of the fluorine atom for one nitro group, F₂NC(NO₂)₂F. The reaction of F₂NC(NO₂)₃ with LiBr in ethanol or DMF affords Br(NO₂)C=NF rather than the expected bromo derivative F₂NC(NO₂)₂Br.     

Mechanism of the primary stages of decomposition of aliphatic nitro- and fluoronitronitramines

The primary stage of the decomposition of compounds RN(NO₂)CH₂C(NO₂)₂X is the homolytic cleavage of the C?NO₂ bond, at X=NO₂ and N?NO₂ bond at X=F. The inductive effect of substituents decreases the dissociation energies of the C?N and N?N bonds by 1–2 kcal mol^?1. Kinetic effects caused by the spatial interaction of groups and by stepwise decomposition of polyfunctional compounds are described.     

Cerium(IV) Nitrate Complexes With Bidentate Phosphine Oxides

The reactions between ceric ammonium nitrate, (NH₄)₂Ce(NO₃)₆, (CAN) and the bidentate phosphine oxides, 4,5-bis(diphenylphosphine oxide)-9,9-dimethylxanthene (L¹), oxydi-2,1-phenylene bis(diphenylphosphine dioxide) (L²), 1,2-bis(diphenylphosphino)ethane dioxide (L³) and 1,4-bis(diphenylphosphino)butane dioxide, L⁴ have been investigated. The crystal structures of the molecular Ce(NO₃)₄L¹ ( 1 ), and ionic [Ce(NO₃)₃L³₂][NO₃]⋅CHCl₃ ( 3 ), [Ce(NO₃)₃L³₂][NO₃] ( 4 ) and the polymeric [Ce(NO₃)₃L⁴_1.5] [NO₃] ( 5 ) and the cerium(III) complex [Ce(NO₃)₂L¹₂][NO₃] ( 2 ) are reported. The thermal stability of the complexes has been examined by thermogravimetry with the gaseous decomposition products analysed by infrared spectroscopy. Evolution of CO₂ is found for both Ce(III) and Ce(IV) complexes with the later also forming NO₂. The formation of the complexes in solution has been studied by ³¹P NMR spectroscopy and further complexes [Ce(NO₃)₃L¹₂]⁺[NO₃]⁻ and [Ce(NO₃)₂L¹₃]²⁺2[NO₃]⁻ identified in CD₃CN solution. The complex ( 1 ) exists as a single molecular species in solution and is stable in dichloromethane whilst ( 3 ) decomposes on standing in both CD₂Cl₂ and CD₃CN to Ce(III) containing species. Complexes of L² have been identified by solution ³¹P NMR spectroscopy and these decompose in solution to give Ce(NO₃)₃L²₂. This study represents the first structural characterisations of Ce(IV) complexes with bidentate phosphine oxides.     

TPD and TPR studies on the reaction between adsorbed NOx species and CH4 over Cu-zeolite

NO₃-type and NO₂-type adsorbed species are formed on Cu-ZSM-5 together with adsorbed O species at 523 K in the decomposition of NO accompanied by the evolution of N₂, N₂O, and NO₂. NO₃-type adsorbed species formed on Cu-ZSM-5 is well reduced with CH₄ around 570 - 600K, while NO₂-type adsorbed species formed on Cu-ZSM-5 was less active on the reduction with CH₄.     

Nitrosyl,nitryl and dioxygenyl hexafluoroplatinate(IV) and (V) and related compounds: Synthesis,reactions and raman spectra

The reactions of PtF₅, O₂PtF₆, PtF₆, IrF₆, NOPtF₆, NO₂PtF₆, NOIrF₆ and NO₂IrF₆ with NOF and NO₂F have been examined under a variety of conditions. The relative ease of synthesis of NOPtF₆, (NO)₂PtF₆, NOIrF₆ and NO₂IrF₆ and the conversion of NOIrF₆ to NOPtF₆ with PtF₆ confirms the order of strong oxidizing properties of Pt^VIF₆, Ir^VIF₆, Pt^VF^-₆ and Ir^VF^-₆. The NO⁺₂ ion is intrinsically unstable with respect to the elimination of oxygen in Pt (IV) and Ir (IV) fluorometallate salts and accordingly there is serious doubt about earlier claims for the synthesis of the (NO⁺)(NO⁺₂)PtF₆ salt. No evidence for the (NO₂)₂PtF₆ could be found.Raman spectral data for NOBF₄, NO₂BF₄, NO₂AsF₆, NOPtF₆, NO₂PtF₆, (NO)₂PtF₆, NOIrF₆, NO₂IrF₆ and (NO)₂IrF₆ are presented and analyzed. The NO⁺₂ ion appears to be linear in all of the compounds and the absence of the Raman forbidden ν₂ fundamental indicates little if any anion-cation interaction at least of the type that leads to a permanent distortion of the cation. In the spectra of all of the nitryl salts, including NO₂BF₄, a low frequency band at about 140 cm^-1 is clearly observed, the intensity and shape of which is a function of the anion. The band probably reflects an unknown lattice dynamic process. No such bands are evident in the spectra of NO⁺ and (NO⁺)₂ salts.     

Molecular aggregation in selected crystalline 1:1 complexes of hydrophobic d‐ and l‐amino acids. IV. The l‐phenylalanine series

The amino acid l ‐phenylalanine has been cocrystallized with d ‐2‐aminobutyric acid, C₉H₁₁NO₂·C₄H₉NO₂, d ‐norvaline, C₉H₁₁NO₂·C₅H₁₁NO₂, and d ‐methionine, C₉H₁₁NO₂·C₅H₁₁NO₂S, with linear side chains, as well as with d ‐leucine, C₉H₁₁NO₂·C₆H₁₃NO₂, d ‐isoleucine, C₉H₁₁NO₂·C₆H₁₃NO₂, and d ‐allo‐isoleucine, C₉H₁₁NO₂·C₆H₁₃NO₂, with branched side chains. The structures of these 1:1 complexes fall into two classes based on the observed hydrogen‐bonding pattern. From a comparison with other l :d complexes involving hydrophobic amino acids and regular racemates, it is shown that the structure‐directing properties of phenylalanine closely parallel those of valine and isoleucine but not those of leucine, which shares side‐chain branching at C^γ with phenylalanine and is normally considered to be the most closely related non‐aromatic amino acid.     

Vibrationally excited NO2 from CH3NO2 and 2-C3H7NO2 photodissociation

We observe vibrationally excited NO₂ from photodissociation of CH₃NO₂ and 2-C₃H₇NO₂ by means of laser induced fluorescence. This approximate method shows very large vibrational excitation in all frequencies of NO₂. The result is interpreted as an indirect predissociation.     

One disorder out of two orders: Synthesis and crystal structures of cation-ordered PbNaF2NO3, anion-ordered Pb2OFNO3, and continuous disordered (Pb,Na)2(O,F)2-δNO3 solid solution with Sillén-derived structures

Two new Sillén–like layered lead fluoride nitrates, PbNaF₂NO₃ and Pb₂OFNO₃, have been prepared at 300 °C. PbNaF₂NO₃ is a structural analog of alkaline earth – bismuth oxyhalides, BaBiO₂X and SrBiO₂X (X = Cl – I), but not the corresponding nitrates, SrBiO₂NO₃ or BaBiO₂NO₃. Pb₂OFNO₃ is analogous to the corresponding halides, Pb₂OFX (X = Cl, Br, I). Both structures belong to orthorhombic symmetry and demonstrate Na/Pb and O/F ordering, respectively. A continuous solid solution is formed between PbNaF₂NO₃ and Pb₂OFNO₃ which demonstrates neither cation nor anion ordering; the structure of intermediate composition Pb_1.5Na_0.5F_1.5O_0.5NO₃ was refined in tetragonal symmetry and is indeed very close to that of PbBiO₂NO₃ and CaBiO₂NO₃. In PbNaF₂NO₃, the O:F ratio may be varied to a slight extent, PbNaF_2-2yO_yyNO₃, which also breaks the Na – Pb cation ordering. Analogous fluoride halides could not be prepared. Structural analogies to lead, bismuth, and antimony oxyhalides are discussed.     

Nitrosyl- und nitryloctafluoroperiodate(VII)

By codestillation of the appropriate mixtures we could prove that NOF or NO₂F resp. and JF₇ react to yield instable compounds NOF·JF₇ and NO₂·JF₇ which exhibit IR-bands at 2260 and 2360 cm^-1 resp. indicating NO⁺ and NO₂⁺ ions and a band at 600 cm^-1 characteristic for JF₈^-. Complete dissociation in the vapour phase is proven by IR-spectra. Vapour pressure data of NO⁺JF₆^- are given. A 1:1 mixture of NOJF₈ and NOJF₆ or NO₂JF₈ and NO₂JF₆ is obtained when NO and NO₂ are combined with JF₇.A new method for the estimation of the pressures of highly corrosive gases is described.     

Secondary interactions in 1‐iodo‐3‐nitrobenzene and 1‐iodo‐3,5‐dinitrobenzene

The crystal packing of 1‐iodo‐3‐nitro­benzene, C₆H₄INO₂, is formed by planar mol­ecules which are linked by I⋯I and NO₂⋯NO₂ interactions. In the case of 1‐iodo‐3,5‐di­nitro­benzene, C₆H₃IN₂O₄, the NO₂ groups are not exactly coplanar with the benzene ring and the mol­ecules form sheets linked by NO₂⋯NO₂ interactions. In contrast with 4‐iodo­nitro­benzene, the crystal structures of both title compounds do not form highly symmetrical I⋯NO₂ intermolecular interactions.     

Interactions between hydrogenated diamond surface and adsorbates with different concentration of NO2 molecules: A first‐principles study

To elucidate the effects of NO₂ and H₂O molecules on the surface conductivity of hydrogenated diamond film, models of various adsorbates containing different molecular ratio of NO₂ and H₂O on hydrogenated diamond (100) surfaces were constructed. The adsorption energies, equilibrium geometries of adsorbates, density of states, and atomic Mulliken populations were studied by using first‐principles method. The results showed that H₂O molecule in the adsorbate could weaken the interactions between the adsorbates and hydrogenated diamond surface significantly. Compared with H₂O molecule, NO₂ molecule relaxes more dramatically when adsorbed on hydrogenated diamond surface. In addition, density of states for C(100):H–2NO₂, C(100):H–NO₂, and C(100):H–NO₂ + H₂O systems are very similar to each other, which indicates an obvious peak at valence band maximum level for all the three samples. It can be attributed to mainly single occupied molecule orbital of NO₂ molecule and slightly C–H bond of C(100):H substrate. When the adsorbates contain one NO₂ and two H₂O molecules, the peak shifts slightly into valence band, but its intensity increases significantly. All the samples exhibit p‐type surface conductivity when adsorbed with pure NO₂ molecules, and the surface conductivity remains as H₂O molecules added into the NO₂ adsorbate layer. However, for oxygenated diamond surface, very week interactions generate between diamond surface and various adsorbates. All the oxygenated diamond (100) surfaces with various adsorbates containing different NO₂ and H₂O molecules on it exhibit an insulating property.     

Conductivities of the Ternary Systems Y(NO3)3+La(NO3)3+H2O, La(NO3)3+Ce(NO3)3+H2O, La(NO3)3+Nd(NO3)3+H2O and Their Binary Subsystems at Different Temperatures

Electrical conductivities were measured for the ternary systems Y(NO₃)₃+La(NO₃)₃+H₂O, La(NO₃)₃+Ce(NO₃)₃+H₂O, La(NO₃)₃+Nd(NO₃)₃+H₂O, and their binary subsystems Y(NO₃)₃+H₂O, La(NO₃)₃+H₂O, Ce(NO₃)₃+H₂O, and Nd(NO₃)₃+H₂O at (293.15, 298.15 and 308.15) K. The measured conductivities were used to test the generalized Young’s rule and the semi-ideal solution theory. The comparison results show that the generalized Young’s rule and the semi-ideal solution theory can yield good predictions for the conductivities of the ternary electrolyte solutions, implying that the conductivities of aqueous solutions of (1:3 + 1:3) electrolyte mixtures can be well predicted from those of their constituent binary solutions by the simple equations.