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The action of aqueous nitrous acid on 2-chloromethylpropene-1 (methallylchloride) results in the formation of an unstable addition product which is converted into 1-chloro-2-methyl-3-nitropropene-1 upon treatment with alkali. For this new compound, the name nitro isocrotyl chloride is proposed. Its structure was established by ozonolysis, which yielded nitroacetone and hydrogen chloride. Dinitrogen tetroxide acts upon methallyl chloride to give a nitronitrite, which may be converted into a nitroalcohol upon treatment with methanol. This nitroalcohol has the probable structure formula 2-chloromethyl-1-nitro-propanol-2.

N2O4 was easily impregnated on polyethyleneglycol to give a stable reagent. Polyethyleneglycol-N2O4 (PEG-N2O4) system was used as an effective oxidizing agent for the oxidation of urazoles and bis-urazoles to their corresponding triazolinediones and also for the aromatization of 1,4-dihydropyridines into the corresponding pyridine derivatives under mild conditions at room temperature with good to excellent yields.

Lithium phenylacetylide (1a) and N2O4 (2) at −78° yield diphenylbutadiyne (6a) by oxidative coupling, phenylacetylene (7a) by oxidation and then solvent H-abstraction, and benzoyl cyanide (8) by dimerizative-rearrangement of nitroso(phenyl)acetylene (23). Nitro(phenyl)acetylene (3, R=Ph) is not obtained. Benzonitrile (9), a further product, possibly results from hydrolytic decomposition of nitroso(phenyl)ketene (27) generated from phenylacetylenyl nitrite (26). Phenylacetylene (7a) and 2 give, along with (E)- and (Z)-1,2-dinitrostyrenes (34 and 35, resp.), 3-benzoyl-5-phenylisoxazole (10), presumably as formed by cycloaddition of benzoyl nitrile oxide (40) to 7a. Further, 2 reacts with other lithium acetylides (1b–1e), and with sodium, magnesium, zinc, copper, and copper lithium phenylacetylides, 1f–1l, to yield diacetylenes 6a–6c and monoacetylenes 7a–7c. Conversions of metallo acetylide aggregates to diacetylenes are proposed to involve generation and addition reactions of metallo acetylide radical cationic intermediates in cage, further oxidation, and total loss of metal ion. Loss of metal ions from metallo acetylide radical cations and H-abstraction by non-caged acetylenyl radicals will give terminal acetylenes. The principal reactions (75–100%) of heavy metal acetylides phenyl(trimethylstannyl)acetylene (44) and bis(phenylacetylenyl)mercury (47) with 2 are directed nitrosative additions (NO+) and loss of metal ions to give nitroso(phenyl)ketene (27), which converts to benzoyl cyanide (8).

Getting heavy: The recently prepared phosphorus analogues of two old acquaintances, urea and dinitrogen tetroxide, bear some structural resemblance to their archetypes but are no carbon copies. Their syntheses and chemical properties reveal rather certain peculiarities, which back the doctrine that the electronic properties of the heavier elements in a group differ from those of the lightest congener.

Dinitrogen tetroxide forms molecular addition compounds with onium and π electron donors, and with anhydrous metal nitrates. Examples and possible structures of these compounds are discussed.

Conventional N234 carbon black was chemically modified by a low temperature treatment with dinitrogen trioxide (N 2 O 3 ), nitrogen oxide (NO) and dinitrogen tetroxide (N 2 O 4 ). The purpose of this treatment was to increase significantly the fraction of polymer chain segments chemically linked to the filler surface in comparison to a conventional CB after compounding with rubber. The theoretical expectation was to reduce the mechanical hysteresis of a rubber compound. The chemical structure of the resulting carbon black (CB) was studied by FT-IR spectroscopy which revealed that an extensive surface chemical modification had occurred. In fact, extensive surface nitration, nitrosation and oxidation had taken place. Raman spectroscopy of treated CB reveals that the bulk structure of the CB remained substantially unchanged after the treatment. The modified CB was tested in practice in a rubber tread compound formulation, and has substantially confirmed the theoretical expectations by reducing the tan 6 at 70°C by about 14%, which correlates with tire rolling resistance without significant losses in traction performances (as estimated on lab scale by tan 6 at 0°C).

N2O4 dissolves in IF5 as NO+NO3–, as established by n.m.r spectroscopy, and in the solid state the solvate complex NO+NO3– · IF5 is formed. This contains a double chain of alternating NO+ cations and NO3– anions. (a = 483.4(2), b = 773.9(1), c = 932.6(3) pm, (α = 70.18(2)°, β = 80.90(3)°, (γ = 87.34(2)°, space group P1, Z = 2). Nitrosoniumnitrat, ein Isomer des N2O4 in Gegenwart von IF5 N2O4 lost sich in IF5 als NO+NO3–, wie mit der Kernresonanzspektroskopie bewiesen wird. Im festen Zustand bildet sich ein Solvatkomplex der Formel NO+NO3– · IF5, welcher eine Doppelkette alternierender NO+-Kationen und NO3–-Anionen enthalt (a = 483.4(2), b = 773.9(1), c = 932.6(3) pm, (α = 70.18(2)°, β = 80.90(3)°, (γ = 87.34(2)°, Raumgruppe P1, Z = 2).

The acetylenic and cumulenic forms of carbyne (α and β-carbyne, respectively) have been obtained simultaneously by oxidative coupling of dicopper acetylide under Glaser conditions. Carbynes having copper atoms, or phenyl groups, at the ends of the chains were successfully synthesized. At room temperature these end-groups confer an indefinite stability to this allotrope, whereas at high temperature in vacuo β-carbyne is transformed to α-carbyne, which is thermodynamically more stable. Carbyne chemical structure was studied and confirmed by FTIR spectroscopy, electronic spectroscopy, and X-ray diffraction. The chemical reactivity of carbyne was checked versus chlorine in the presence of UV light and dinitrogen tetroxide. The specific conductivity of undoped carbyne obtained by Glaser synthesis was found to be in the range 2·11×10-6–1·41×10-6Scm-1, just one order of magnitude lower than the conductivity of trans-polyacetylene. Polyeneyne or ‘Straus carbyne’ was synthesized via the Straus reaction and its structure was studied by FTIR and electronic spectroscopy. ©1997 SCI

Le tetroxyde d'azote liquide N 2 O 4 et les melanges d'oxyde azotique utilises en tant qu'oxydant dans les propergols de fusees contiennent des produits de reaction du N 2 O 4 avec presence aleatoire d'eau. La determination de la concentration globale d'eau et d'especes aqueuses, designees par leur teneur d'equivalent eau, est importante du point de vue de l'effet des produits d'hydrolyse sur la vitesse de corrosion des reservoirs metalliques et sur l'etat physique des produits de corrosion, La spectrometrie RMN de protons a transformee de Fourier a intensite de champ elevee est desormais utilisable pour la mesure directe de la teneur en equivalent eau des melanges MON jusqu'au MON-3, sans oxydation prealable. Une oxydation donne toutefois une precision legerement meilleure. La methode s'avere une methode absolue fiable pour la determination de la teneur en equivalent eau pour des valeurs aussi faibles que 0,003% en poids jusqu'a au moins 0,2% en poids. La precision de la methode dans ce domaine est de l'ordre de 5%:on estime que la teneur en equivalent eau pourrait etre determinee jusqu'a des valeurs aussi basses que 0,00021% en poids. Des eprouvettes de N 2 O 4 , telles que celles fabriquees pour les analyses RMN, restent stables pendant plus d'un an dans des tubes en verre scelles.

Getting heavy: The recently prepared phosphorus analogues of two old acquaintances, urea and dinitrogen tetroxide, bear some structural resemblance to their archetypes but are no carbon copies. Their syntheses and chemical properties reveal rather certain peculiarities, which back the doctrine that the electronic properties of the heavier elements in a group differ from those of the lightest congener.

Ab initio calculations at the MP2 level with the 6-31G * and 6-311G * basis set satisfactorily reproduced the experimental structural and vibrational spectral features of the D 2h conformer of dinitrogen tetroxide. Calculations at the same level, however, indicate the D 2d conformation of this molecule is a transition state for the torsional motion around the N-N bond. Therefore, the previously observed matrix infrared spectral features should not be attributed to the D 2d structure of dinitrogen tetroxide

The novel epoxidation of diadamantylidene 1 and related hindered olefins with NO2 proceeds by way of the cation radical 1+˙ generated during the electron-transfer chain (ETC) catalysis initiated by nitrosonium.

Reaction of N2O4 with 1,2-dimethylcyclohexene led to the corresponding dinitro compound 4 with high trans stereoselectivity (>30:1). Catalytic hydrogenation of 4 with Pd(OH)2 on carbon afforded a quantitative yield of (d,l)-1,2-diamino-1,2-dimethylcyclohexane, which was resolved to pure enantiomers with mandelic acid. This approach constitute a simple and potentially general route to interesting new chiral auxiliaries.

A series of 4-methyl-3-(arylthio)furoxans were synthesized by oxidation of 1-(arylthio)-2-methylglyoxymes with dinitrogen tetroxide. Reduction with trimethyl phosphite of the furoxan derivatives afforded the corresponding furazans, while oxidation with an equimolar amount of 30% hydrogen peroxide in acetic acid or with an excess of 81% hydrogen peroxide in trifluoroacetic acid afforded the corresponding arylsulfinyl and arylsulfonyl analogues, respectively. All the furoxan and furazan derivatives showed activity as inhibitors of platelet aggregation. 4-Methyl-3-(arylsulfonyl)furoxans were the most potent derivatives of the series. 4-Methyl-3-(phenylsulfonyl)furoxan (10a), one of the most active derivatives, inhibits the AA-induced increase of cytosolic free Ca2+ and production of malondialdehyde. A primary action of the compound on cyclooxygenase is excluded, as a stable epoxymethano analogue of prostaglandin H2 does not reverse the inhibitory effect of 10a. This compound produces a significant increase in cGMP which is likely to cause inhibition at an early stage of the platelet activation pathway.

Alkyl 2-aminoethyl hydrogen phosphates (phosphatidyl ethanolamines) were prepared via phosphoramidite chemistry. tert-butoxy-carbonyl N-protection of 2-aminoethanol, followed by cyclisation with phosphorus(III) chloride gave the phosphoramidite 3-tert-butoxycarbonyl-2-chloro- 1,3,2-oxazaphospholidine (3). This reacted with long chain alcohols (C6 to C18) to give 2-alkyloxy-3-tert-butoxvcarbonyl-1,3,2-oxazaphospholidines 4a-d which were oxidised to 2-alkyloxy-3-tert-butoxycarbonyl-2-oxo-1,3,2-oxaza-phospholidines 5a-d with dinitrogen tetroxide. Simultaneous heterocycle cleavage and N-deprotection were achieved with refluxing aqueous tetrahydrofuran, to give the target 2-aminoethyl phospates

Monolayer coverages of N2O4 have been prepared via the adsorption of gaseous NO2 at ca. 100 K on 5–10 monolayers (ML) of condensed H2O in a high vacuum system. Exposure to continuous near-UV irradiation resulted in the photodesorption of NO2 from the surface. The interaction with the ice was purely physical in character and there was no reaction between NO2 and the water surface. Grazing incidence FTIR spectroscopy identified adsorbed N2O4 as the sole parent species which, in addition, had a preferred orientation on the surface: the N—N bond was oriented perpendicular to the surface plane. The temporal profiles of both the NO2 photodesorption rate and of the surface-bound N2O4 concentration exhibited simple monotonic decays and were explained within a simple kinetic scheme for the photochemistry of adsorbed N2O4. The wavelength dependence of the NO2 yield was comparable to the gas-phase absorption cross-section for N2O4. The experiments show that the photochemistry of N2O4 physisorbed on low-temperature ice is not significantly different to that of its gas-phase counterpart.

A new two step procedure is developed for the half-reduction of lactams to cyclic imines and enamines. N-Nitrosation using dinitrogen tetroxide furnishes N-nitroso lactams, which undergo chemoselective 1,2-reduction to N-nitroso carbinolamines by one equivalent of hydride delivered from lithium triethylborohydride. The nitroso group is cleaved in a novel way using samarium(II) iodide and dehydration then generates the corresponding imine (which may tautomerise to the isomeric enamine). The reduction can be performed in the presence of esters and has proved efficient for the preparation of 2H-pyrroles (pyrrolenines) and 1H-pyrroles relevant to the study of tetrapyrrole biosynthesis.

Fe(NO3)3. 1.5 N2O4 and Cu(NO3)2. N2O4 are easily prepared reagents for the efficient and selective mono- or dinitration of phenolic compounds. In comparison with metal nitrates, these complexes resemble a synergetic effect on the rates and the yields of the reactions. High ratio of p-nitrophenol formation vs o-nitrophenol is also observed in the mononitration reactions.

A catalytic and efficient oxidative coupling of thiols to disulfides is described using Cu(NO3)2.N2O4 as a new and efficient nitrosating agent in acetone at room temperature. The reaction is shown to occur immediately through the intermediacy of a thionitrite.

Fe(NO3)3. 1.5 N2O4 and Cu(NO3)2.N2O4 are new, stable, and highly efficient reagents for the quantitative transformation of sulfides to sulfoxides in dichloromethane or in the absence of solvent at room temperature. Cu(NO3)2.N2O4 is highly selective for the oxidation of aryl sulfides.

The nitration of aromatic compounds may be achieved with many nitrating reagents and is a very useful way in organic synthesis 1 . Also, nitro compounds find use in many industrial applications2.3 and para isomers are commonly the more commercially desirable products,e.g., p-nitrotoluene vs o-nitrotoluene or p-nitrophenol vs o-nitrophenol and production of 2-nitroestrone versus 4-nitroestrone is important from pharmaceutical point of view4 . Nitration of the phenol as a special case has been studied by various nitrating agents under different conditions4.1 5. Very recently, Rodrigues et al. reported that phenol can be nitrated by silica gel-supported acetyl nitrate with excellent ortho regioselectivity l6. Although a survey of the l iterature indicates the lack of entire selectivity of para nitration of phenol but almost selective ortho nitration of phenol was performed with N204 and pyridine derivatives carrying transferable nitro group or silica gel­ supported acetyl nitrate6. 16. It is clear that, on the basis of the above facts there is a need for more regioselective control of nitration of aromatic compounds. Recently, in this connection we have reported the applications and mechanism of some hydrated metal nitrates and their dinitrogen tetroxide complex analogues for nitration of phenols under different conditions 17. We have also demonstrated that in situ formation of HN03 is a major factor for an effective nitration of phenols with metal nitrates (containing covalent nitrato groups ) 1 7a. Our goal, in undertaking this line of work, was two-fold: a) to overcome the limitations and drawbacks of the reported methods such as : tedious work-up,9. 1 1 strongly acidic media (Ho_8),4b oxidation ability of the reagents and safety problems (storage, handling, using and also presence of toxic transition metal cations such as Cr+3, Hg+2, Cu+2 , . . . within molecular structure of the reagents) 1 8.19, (b) moreover, constraining a reaction to the surface of solid habitually allows to use milder conditions and increases its reactivity2o. Very recently, we among many others have demonstrated that heterogeneous reagent systems have many advantages such as simple experimental procedures, mild reaction conditions and minimization of chemical wastes as compared to their liquid phase counterparts. We have reported simple procedures for in situ generation of 'nitrosonium ion (NO+) under mild and heterogeneous conditions and also applications of it for different purposes21 . Therefore, we decided to seek a heterogeneous system for selective nitration of phenol, and we have investigated a number of different reaction conditions based upon the in situ generation of HN02 by relatively strong solid inorganic acidic salts [NaHS04.H20, Mg(HS04h. pka-2] and sodium nitrite. We wish to report here in one-pot heterogeneous procedure for nitration of phenols.

The C-2 lithiation of N -Boc- and N -(phenylsulfonyl)indoles ( 4 – 7 ) followed by reaction with dinitrogen tetroxide at low temperature affords the corresponding 2-nitroindoles 10 – 13 in 63–78% yields. Deprotection of the N -Boc-2-nitroindoles ( 10 , 11 ) with trifluoroacetic acid gives 2-nitroindole ( 3 ) and 3-methyl-2-nitroindole ( 14 ) in essentially quantitative yields.

Gaseous N2O4 was immobilized on polyvinylpyrrolidone to give a stable polymeric reagent. Thiols were converted to S-nitrosothiols (thionitrites) using this new nitrosating agent in n-hexane or CHCl3 at 10°C. With this reagent, thiols were also converted into their corresponding disulfides. Selective oxidation of sulfides to sulfoxides and disulfides to thiosulfonates can also be achieved by this reagent at room temperature. By using an excess of the reagent, the selective one-pot synthesis of thiosulfonates from thiols at room temperature was also performed.

From the reaction products obtained by treating 3-carene with dinitrogen tetroxide a crystalline compound N-[(1R,6R)-3-methyl-6-(1-methyl-1-nitroxyethyl)cyclohex-3-enyl]-N'-{1S,6S)-4- methyl-6(1- methyl-1-nitroxyethyl)cyclo-hex-3-enyl]-E-diazene-N,N'-dioxide was isolated. Mainly nitrate of α-terpineol formed in reaction of 3-carene with 70% nitric acid.

Guanidine condensed with 1,4-diformyl-2,3,5,6-tetrahydroxypiperazine 1 to give 2,6-diiminodecahydro-1H,5H-diimidazo[4,5-b:4′,5′-e]pyrazine 3 isolated as the tetrahydrochloride salt. nitric acid (100%) at −40°C converted the bisguanidine 3 to 2,6-dinitrimino-4,8-dinitrodecahydro-1H,5H-diimidazo[4,5-b:4′,5′-e]- pyrazine 8 isolated as a dihydrate, whereas nitration by nitronium tetrafluoroborate at 0° to 25°C afforded 2,6-diimino-4,8-dinitrodecahydro-1H,5H-diimidazo[4,5-b:4′,5′-e]pyrazine 9 isolate as the monohydrated bistetrafluoroborate salt, and treatmetn with nitric acid (100%) and acetic anhydride or phosphorus pentoxide converted the bisguanidine 3 to 2,6-dioxo-1,3,4,5,7,8-hexanitrodecahydro-1H,5H-diimidazo[4,5-b:4′,5′-e]pyrazine 4, also obtained from the tetra N-nitro compound 8 · 2 H2O and from the dinitramine 9 · 2 BHF4 · H2O after similar treatment. The cis-syn-cis- configuration of the tricyclic bisurea 4 and bisguanidine 9 was confirmed by X-ray crys-tallographic analysis. Nitrosation by nitrous acid or by dinitrogen tetroxide converted the bisguanidine 3 to a hydrated 2,6-dinitrosimino-4,8-dinitrosodecahydro-1H,5H-diimidazo[4,5-b:4′,5′-]pyrazine 10 · 2.5 H2O, whereas treatment with nitrosonium tetrafluo-roborate afforded the bistetrafluoroborate salt of 4,8-dinitroso derivative 11 · 2 BHF 4. The nitrosamines 10 and 11 were converted to the tetranitro compound 8 · 2 H2O on treatment with nitric acid (100%) at −40°C. Treatmnt with fluoroboric acid etherate in acetonitrile converted nitroimino groups in compound 8 · 2 H2O and nitrosimino groups in compound 10 · 2.5 H2O to imino groups in compounds 9 · 2 BHF2 · H2O and 11 · 2 HBF4 respectively.

In this paper we report the computational results of a density functional study of 73 UN4O12 isomers containing uranyl nitrate, UO2(NO3)2, as a component. The isomers are grouped into three categories and 19 types. Forty-four isomers of 14 types are dinitrogen tetroxide adducts of uranyl nitrate, UO2(NO3)2·N2O4, 22 are nitrosonium salt adducts of uranyl nitrate, NO+UO2(NO3)3-, NO+UO2(NO3)2O(NO2)-, NO+UO2(NO3)2(ONOO)-, or (NO+)2UO2(NO3)2O22-, and 7 are bis(nitrogen dioxide) adducts of uranyl nitrate, UO2(NO3)2·2NO2. The 22 most stable isomers in solution, representing the 20 most stable gas-phase isomers, were selected for analysis. Of these selected structures only two categories and six types were represented. Structures, frequencies, gas-phase and solution energetics, atomic charges, dipole moments, and the bonding within the N2O4 unit and between NO+ and UO2(NO3)3- components have been analyzed in detail. On the basis of relative Gibbs free energy calculations five isomers (the N2O4 adducts a1, a2, and...

Selective oxidation of thiols to disulfides (RSSR) was performed by using catalytic amounts of dinitrogen tetroxide/charcoal in chloroform at r.t. while the reaction of thiols with four molar equivalents of the reagent in dichloromethane afforded thiosulfonates (RSO2SR) with excellent yields.

The synthesis and characterization of the ternary U-O-N compound NO(+)UO2(NO3)3- (1) using IR and low-temperature and room-temperature Raman spectroscopy as well as 14N and 15N NMR spectroscopy are reported. In addition, solution Raman spectra of compound 1 recorded in various solvents are reported. The structure of compound 1 was determined using single-crystal X-ray diffraction techniques: monoclinic, C2/c, a = 13.3992(4) angstroms, b = 9.9781(4) angstroms, c = 7.6455(2) angstroms, beta = 115.452(2) degrees, V = 922.98(5) angstroms3, Z = 4. Compound 1 is highly moisture-sensitive and must be handled under an inert atmosphere. It reacts with water with the liberation of NO2. For the first time, this important precursor for the synthesis of anhydrous uranyl nitrate could be unambiguously identified and has been shown to be an ionic nitrosonium salt and not an adduct between uranyl nitrate and dinitrogen tetroxide, UO2(NO3)2.N2O4, as is incorrectly and predominantly cited in the literature.

Efficient N‐nitrosation of amines, amides, and ureas, and also S‐nitrosation of thiols were performed with dinitrogen tetroxide impregnated on activated charcoal (N2O4/charcoal) in CH2Cl2 at room temperature. High selectivity was observed for N‐nitrosation of dialkyl amines, N‐alkylamides and N‐alkylureas. Dealkylation and N‐nitrosation of trialkylamines were also performed by this reagent.

Dinitrogen tetroxide was easily impregnated on activated charcoal to give a stable heterogeneous reagent (N 2 O 4 /charcoal). The chemoselective oxidation of sulfides to sulfoxides in the presence of different sensitive functional groups was achieved using this reagent in CH 2 Cl 2 at room temperature. Dialkyl sulfides were also selectively converted to their corresponding sulfoxides in the presence of diaryl or alkyl-aryl sulfides. Oxidation of disulfides to thiosulfonates without any over oxidation was also performed at room temperature by this system.

The oxidation of thiols with N2O4 to sulfonic acids is presented. One compound 5b shows lyotropic liquid crystalline properties.

Synthese des composes du titre et d'analogues [benzo [b] thienyl-3]-5 a partir des oximes des [naphtyl-2]-1- et heteryl-1 alcene-1ones-3 correspondantes

Die Tetraketone 3 reagieren mit Distickstofftetroxid zu den 4,5-Dioxo-4,5-dihydro-pyridazin-1,2-bis-oxiden 4, die sich in trockenem Zustand leicht explosionsartig zersetzen. Preparation of 3,6-Diacyl-4,5-dioxo-4,5-dihydropyridazine 1,2-Dioxides The tetraketones 3 react with dinitrogen tetroxide to give the 4,5-dioxo-4,5-dihydropyridazine-1,2-dioxides 4. Compounds 4 explode easily when they are dry.

Die Triaminobenzole 2reagieren mit Distickstofftetroxid (N2O4) zu den Nitrosoverbindungen 4, wahrend selbst so reaktive Aromaten wie N,N-Dimethylanilin mit N2O4 nitriert werden. Diese Divergenz in der Produktbildung last sich uber die unterschiedlichen Nucleophilie der Aromaten und die verschiedenen Dissoziationsmoglichkeiten des N2O4 deuten. Die Verbindungen 4 und 7 werden ausschlieslich am Nitrososauerstoff alkyliert und protoniert; die UV-und 1H-NMR-Spektren der dabei gebildeten Chinoniumsatze 9, 10 werden diskutiert und gedeutet. Uber Pd/Aktivkohle lassen sich die Nitrosobenzole 4 zu den entsprechenden Anilinen 14 hydrieren. Eine praparative brauchbare Diazotierung dieser Amine gelingt nicht, dagegen reagieren die 4-Nitroso-N,N-dialkylaniline 15 mit NO in guten Ausbeuten zu den bemerkenswert stabilen Diazonium-nitraten 16. Aminobenzenes, IX. Formation and Reactions of 1,3,5-Tris(dialkylamino)-2-nitrosobenzenes The triaminobenzenes 2 react with dinitrogen tetroxide (N2O4) to yield the nitroso compounds 4 while even arenes as reactive as N, N- dimethylaniline are nitrated by N2H4. This discrepancy in the product formation can be rationalized in terms of increasing nucleophilic potential of the aromatic substrates and in terms of different dissociation pathways of the N2O4. This discrepancy in the product formation can be rationalized in terms of increasing nucleophilic potential of the aromatic substrates and in terms of different dissociation pathyways of the N2O4 moiety. Alkylation and protonation of compounds 4and 7 takes place exclusively at the nitroso oxygen; the u. v. and 1H n. m. r. spectra of the quinone imonium salts 9, 10thus formed are analyzed and discussed. Reduction of the nitrosobenzenes 4with a Pd/C catalyst affords the anilines 14. Diazotation of these amines was not successful on a preparative scale whereas the 4-nitroso-N,N-dialkylanilines 15 react with NO to form the remarkably stable diazonium salts 16in good yield.

Die Oxydation von RN(PF2)2 mit N2O4 in n-Hexan fuhrt in guten Ausbeuten zu den Bis(difluorophosphoryl)-amiden RN(POF2)2 (R = Me, Et). Mit Phenylazid wird nur ein Phosphoratom oxydiert und es werden 1,3-Diphenyl-2,4-bis(difluorophosphor(III)-N-alkylamido)-2,2,4,4-tetrafluoro-diaza-λ5,λ5-diphosphetidine, [F2PN(R)PF2NPh]2, erhalten. Investigations on the Oxidation of N-Alkyl-bis(difluoro-phosphorus(III))amides Oxidation of RN(PF2)2 by N2O4 in n-hexane leads to bis(difluorophosphoryl)amides, RN(POF2)2 (R = Me, Et), in good yields. Only one phosphorus atom is oxidized by phenylazide resulting in the formation of 1.3-diphenyl-2.4-bis(difluorophosphorus(III)-N-alkyl-amido)-2.2.4.4-tetrafluoro-diaza-λ5,λ5 diphosphetidines, [F2PN(R)PF2NPh]2.

Results of an investigation of the kinetic stability and viscosity of solutions of cellulose blends with poly(vinyl acetate), poly(vinylidene chloride) and poly(vinyl alcohol) in dimethylformamide or ethylacetate containing dinitrogen tetroxide at different cellulose-synthetic polymer ratios are presented. Die Ergebnisse einer Untersuchung der kinetiscben Stabilitat und Viskositat der Losungen von Miscbungen aus Cellulose mit Poly(vinylacetat), Poly(vinylidenchlorid) und Poly(vinylalkohol) unterschiedlicher Zusammensetzung werden mitgeteilt. Als Losungsmittel dienten Dimethylformamid bzw. Ethylacetat, die Distickstofftetroxid enthielten.

The reactions involved in the removal of nitrogen oxides from gases by reaction with water are reversible and proceed at a finite rate. It is possible therefore that the over-all process is controlled by the rate of the chemical reactions. On this basis an analysis of the process has been developed by the application of chemical kinetics, with consideration of reactions involving both nitrogen dioxide and dinitrogen tetroxide. The resulting differential equation has been simplified and integrated to give a final equation which can be tested experimentally. Theoretical methods are presented for predicting the extent of absorption of nitrogen oxides at various gas rates and concentrations and are compared with the experimental results. The paper presents some new concepts of the factors which control the rate of absorption of nitrogen dioxide and dinitrogen tetroxide in water. An understanding of the controlling factors in the process should indicate methods for improving the design of absorption towers in nitric acid plants and aid in the design of scrubbers for removing nitrogen oxides from waste gases.

Representative 4-isothiazolin-3-one I-oxides and I, I-dioxides have been prepared by the reaction of m-chloroperbenzoic acid with the respective 4-isothiazolin-3-ones. Chromic acid, dinitrogen tetroxide, and nitric acid have also been successfully employed in the oxidation of several 3-hydroxyisothiazoles to their respective I-oxides.

The reaction of liquid hydrogen fluoride with nitrous acid, dinitrogen trioxide, dinitrogen tetroxide, and nitrosyl compounds leads to unexpectedly high-boiling liquids which contain nitrosyl fluoride in the form of remarkably stable, electrolytically dissociated hydrogen fluoride solvates. Nitrosyl fluoride solvated by pure hydrogen fluoride is a new reagent, valuable in fluorine chemistry since it reacts with many elements and compounds to form fluorine derivatives of preparative importance.

Raman and infrared spectra of polycrystalline samples of N2O4 at low temperatures have been recorded. The number and activities of the fundamentals are compared with the predictions of group theory, based on the known molecular and crystal geometries. Several additional peaks are attributed to Fermi resonances of combinations with fundamentals. A new low frequency internal mode and five lattice modes have been observed.