Mechanism of formation of hydrogen trioxide (HOOOH) in the ozonation of 1,2-diphenylhydrazine and 1,2-dimethylhydrazine: an experimental and theoretical investigation

Low-temperature (-78 degrees C) ozonation of 1,2-diphenylhydrazine in various oxygen bases as solvents (acetone-d(6), methyl acetate, tert-butyl methyl ether) produced hydrogen trioxide (HOOOH), 1,2-diphenyldiazene, 1,2-diphenyldiazene-N-oxide, and hydrogen peroxide. Ozonation of 1,2-dimethylhydrazine produced besides HOOOH, 1,2-dimethyldiazene, 1,2-dimethyldiazene-N-oxide and hydrogen peroxide, also formic acid and nitromethane. Kinetic and activation parameters for the decomposition of the HOOOH produced in this way, and identified by (1)H, (2)H, and (17)O NMR spectroscopy, are in agreement with our previous proposal that water participates in this reaction as a bifunctional catalyst in a polar decomposition process to produce water and singlet oxygen (O(2), (1)delta(g)). The possibility that hydrogen peroxide is, besides water, also involved in the decomposition of hydrogen trioxide is also considered. The half-life of HOOOH at room temperature (20 degrees C) is 16 +/- 1 min in all solvents investigated. Using a variety of DFT methods (restricted, broken-symmetry unrestricted, self-interaction corrected) in connection with the B3LYP functional, a stepwise mechanism involving the hydrotrioxyl (HOOO(*)) radical is proposed for the ozonation of hydrazines (RNHNHR, R = H, Ph, Me) that involves the abstraction of the N-hydrogen atom by ozone to form a radical pair, RNNHR(*) (*)OOOH. The hydrotrioxyl radical can then either abstract the remaining N(H) hydrogen atom from the RNNHR(*) radical to form the corresponding diazene (RN=NR), or recombines with RNNHR(*) in a solvent cage to form the hydrotrioxide, RN(OOOH)NHR. The decomposition of these very labile hydrotrioxides involves the homolytic scission of the RO-OOH bond with subsequent "in cage" formation of the diazene-N-oxide and hydrogen peroxide. Although 1,2-diphenyldiazene is unreactive toward ozone under conditions investigated, 1,2-dimethyldiazene reacts with relative ease to yield 1,2-dimethyldiazene-N-oxide and singlet oxygen (O(2), (1)delta(g)). The subsequent reaction sequence between these two components to yield nitromethane as the final product is discussed. The formation of formic acid and nitromethane in the ozonolysis of 1,2-dimethylhydrazine is explained as being due to the abstraction of a methyl H atom of the CH(3)NNHCH(3)(*) radical by HOOO(*) in the solvent cage. The possible mechanism of the reaction of the initially formed formaldehyde methylhydrazone (and HOOOH) with ozone/oxygen mixtures to produce formic acid and nitromethane is also discussed.     

Microwave-assisted synthesis of 5-trichloromethyl substituted 1-phenyl-1H-pyrazoles and 1,2-dimethylpyrazolium chlorides

A series of five 5-trichloromethyl-1-phenyl-1H-pyrazoles and six 5-trichloromethyl-1,2-dimethylpyrazolium chlorides have been synthesized in 80-98% yield by environmentally benign microwave induced techniques involving the cyclocondensation of 4-alkoxy-1,1,1-trichloro-3-alken-2-ones [Cl₃C(O)C(R²)=C(R¹)OR, where R²=H, Me; R¹=H, alkyl, phenyl and R=Me, Et] with phenyl hydrazine and 1,2-dimethylhydrazine dihydrochloride, respectively, using toluene as solvent. The use of microwave and classical methods are comparable for making pyrazoles, but the formation of pyrazolium chlorides can be achieved in a significant shorter time, and in some cases better yield.     

Synthesis,structure, and characteristics of 1,2-dichlorovinyl alkyl ketones

A method of alkyl 1,2-dichlorovinyl ketones preparation from acyl halides and 1,2-dichloroethylene was developed. The configurational equilibrium and electronic structure of alkyl 1,2-dichlorovinyl ketones was investigated by IR, ¹H and ¹³C NMR spectroscopy, by measuring dipole moments, and by quantum-chemical calculations using methods RHF and B3LYP in the basis 6–311++G (d,p). Alkyl 1,2-dichlorovinyl ketones are stable in the Z, s-cis-configuration where the olefin proton is involved into an intramolecular hydrogen bond with the oxygen of the carbonyl group. Reaction of 1,2-dichlorovinyl ketones with alkylhydrazines afforded 1-alkyl-3-alkyl-4-chloropyrazoles. The reaction of alkyl 1,2-dichlorovinyl ketones with 1,1-dimethylhydrazine involved dehydrochlorination and afforded 1,1-dimethylhydrazinium hydrochloride and a mixture of compounds with uncertain structure.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 11, 2004, pp. 1632–1640.Original Russian Text Copyright © 2004 by Bozhenkov, Leckovskaya, Larina, Ushakov, Dolgushin, Mirskova.     

New cyclic aminimides containing pyrazolone skeleton

The synthetic route to 1,1-dimethylpyrazolin-5-on-1,2-aminimides ($\text{2}$), is described, involving the cyclization of diethyl acylmalonates ($\text{1}$) with 1,1-dimethylhydrazine.     

Ring closures with α-chloroazines

Two series of unsymmetrical 3,6-disubstituted 1,2,3,4-tetrahydro-1,2,4,5-tetrazines and 3,5-disubstituted 4-amino-2,3-dihydro-1,2,4-triazoles were synthesized from unsymmetrical 1,4-disubstituted 1-chloroazines with hydrazine, 1-methylhydrazine, and 1,2-dimethylhydrazine. These partially reduced heterocycles belong to little known and less accessible classes of heterocycles.     

Mutagenicity tests with a permeable mutant of yeast on carcinogens showing false-negative in Salmonella assay

The mutagenicity (Trp+ reversion) of procarcinogens such as N-nitrosodimethylamine, 3,4-benzpyrene and 2-acetylaminofluorene has been detected with the permeable mutant of yeast, Saccharomyces cerevisiae C658-K42. The original strain C658, however, showed a positive response only to N-nitrosodimethylamine with S9 mix. The permeable mutant C658-K42 was employed for mutagenicity tests on 12 carcinogens which had been reported to be non-mutagenic in Salmonella/microsome tests. It was found that phenobarbital, thiourea, 1,2-dimethylhydrazine and 4-aminoantipyrine were mutagenic in the presence of S9 mix. Benzene, o-toluidine and thioacetamide were weakly mutagenic. Negative results were obtained for diethylstilbestrol, safrole, acetamide, urethane and ethionine at the concentrations used. Caprolactam did not show any mutagenic effect on C658-K42 at concentrations up to 20 mg/ml. Sodium azide, which is unlikely to be carcinogenic but is strongly mutagenic in the Ames test, showed a very weak mutagenic effect on C658-K42.     

Diazepines. V. The reaction of homophthalic anhydride with hydrazines

The reaction of homophthalic anhydride with hydrazine and a number of substituted hydrazines has been investigated. Only in the case of the reaction of homophthalic anhydride and 1,2-dimethylhydrazine has a diazepine been isolated. The previously reported (2) diazepine from homophthalic anhydride and hydrazine appears to be a product resulting from the reaction of twomolec of homophthalic anhydride with one mole of hydrazine.     

Ab initio studies of structural features not easily amenable to experiment: Part III. The influence of lone pair orbital interactions on molecular structure

The characteristic structural asymmetries and distortions of AXYB systems in which an electron lone pair is at Y are discussed on the basis of the completely relaxed ab initio equilibrium geometries of a number of representative systems including various conformations of methanediol, hydrazine, 1,2-dimethylhydrazine and of compounds with CH₃ groups adjacent to OH, OCH₃, NH, NCH₃ and C(π). It is found that, regardless of quantitative overlap and energy gap factors, all calculated trends in the relative extensions of bond distances and bond angles can be correlated in every detail to qualitative predictions based only on the orientational aspects of orbital interaction concepts.     

Rotational isomerism as studied by nuclear quadrupole coupling.: Theoretical and experimental 14NX tensors for hydrazine,methylhydrazine, and 1,2-dimethylhydrazine

The nuclear quadrupole coupling constants of the ¹⁴N nuclei for hydrazine, the inner and outer conformers of methylhydrazine, and the inner-outer and the outer-outer conformers of 1,2-dimethylhydrazine are calculated by an ab initio SCF method, and also by a CI calculation for hydrazine. The results are compared with available experimental values. Characteristic dependence of the X tensors on the conformational structure is demonstrated. An application of theoretical hyperfine structures to a spectral analysis is discussed.     

Fundamental equilibrium analysis on the ion-pair extraction of dibenzo-18-crown-6 complex of alkali metal ions with picrate ion into 1,2-dichloroethane

The ion-pair extraction equilibria of dibenzo-18-crown-6 (DB18C6) complexes of Na⁺, K⁺, Rb⁺ and Cs⁺ (M⁺) with picrate ion (Pic⁻) into 1,2-dichloroethane (1,2-DCE) have been studied at 25.0°C. In the case of the Rb⁺ and Cs⁺ systems, the extraction results were interpreted by taking into consideration the formation of a (DB18C6)₂ -M⁺ complex in 1,2-DCE. The thermodynamic constants of extraction, , and ion-pair formation in 1,2-DCE, , of ion pairs of the DB18C6-M⁺ complexes with Pic⁻ were determined. By using the distribution coefficient of M⁺·Pic⁻ the thermodynamic formation constants of the DB18C6-M⁺ complexes in 1,2-DCE, , were evaluated. Consequently the component equilibrium constants of the ion-pair extraction were completely determined and a contribution of these constants to the difference of value was discussed. The value in 1,2-DCE is quite high compared with that in solvating solvents and log decreases linearly with increasing Gutmann donor number of solvents.     

Hydration to benzo-15-crown-5, benzo-18-crown-6 and the benzo-18-crown-6-potassium ion complex in the low-polar organic solvents.

The coextraction of water with benzo-15-crown-5 (B1SC5), benzo-18-crown-6 (B18C6) and the B18C6-K+ complex into seven low-polar solvents, i.e., carbon tetrachloride (CTC), chloroform (CF), dichloromethane (DCM), 1,2-dichloroethane (1,2-DCE), benzene (BZ), chlorobenzene (CB) and o-dichlorobenzene (o-DCB), has been investigated. The mean hydration number, nH2O, of these solutes in the water-saturated organic solvents was determined. There is a trend that the nH2O values for any solutes increase with increasing the water concentration in the solvents. Those of B18C6 and B15C5 converge at almost 0.8 for B18C6 and 0.4 - 0.5 for B15C5 in the solvents with the relatively high water concentration, i.e., CF, 1,2-DCE, DCM, and nitorobenzene (NB). The nH2O value of B15C5 is about one-half of that of B18C6 for a given organic solvent. The dominant species of the B18C6-K+ complex in these solvents is non-hydrated. From these results, the hydration equilibrium constants, KH2O, in the organic solvents were estimated.     

Chemistry of stable iminopropadienones, RN=C=C=C=O

The synthesis, spectroscopic properties, and chemical reactions of the stable (neopentylimino)-, (mesitylimino)-, and (o-tert-butylphenylimino)propadienones (6) are reported. Nucleophilic addition of amines affords the malonic amidoamidines 7 and 8. 3,5-Dimethylpyrazole reacts analogously to form 9b. Addition of 1,2-dimethylhydrazine produces pyrazolinones 10-12. Addition of N,N'-dimethyldiaminoethane, -propane, and -butane gives diazepine, diazocine, and diazonine derivatives 13-15, respectively (X-ray structures of 13c, 14a, and 15a are available). The mesoionic pyridopyrimidinium olates 18 are obtained by addition of 2-(methylamino)pyridine (X-ray structure of 18b available). Primary 2-aminopyridines afford the pyridopyrimidininones 20-29 and 31 (X-ray structure of 21a available), and 2-aminopyrimidines and 2-aminopyrazine afford pyrimidopyrimidinones and pyrazinopyrimidinones 33-35. Pyrimidoisoquinolinone 36 results from 1-aminoisoquinoline and pyridoquinolinone 40 from 8-aminoquinoline. 2-Aminothiazoline and 2-aminothiazole afford thiazolopyrimidinone derivatives 41-43 (X-ray structure of 43a available).     

Synthesis and Crystal Structure of One-dimensional Chain Complexes [K(18-C-6)]2[M(mnt)2](M=Zn, Hg)

IntroductionThe 1 ,2 - dicyanoethene- 1 ,2 - dithiolato anion isa bidentate ligand.It can form square- coplanarcomplexes with many transition metal ions and hasfound a lot of application in analytical chemistry,catalyst and biochemistry.In recent years,metalcomplexes containing mnt and its dithiolate analogligands have been extensively studied and have re-ceived considerable attention due to their potentialapplication in charge transfer and storage,molecu-lar metals,magnetic materials,supercon…     

Two-dimensional Network Crown Ether Complex. Synthesis and Crystal Structure of 18-Crown-6 Complex: [K(18-C-6)]_2[Cd-(mnt)_2]

ＩｎｔｒｏｄｕｃｔｉｏｎＲｅｃｅｎｔｙｅａｒｓ ,ｃｏｏｒｄｉｎａｔｉｏｎｐｏｌｙｍｅｒｓｈａｖｅｂｅｅｎｒｅ ｃｅｉｖｅｄｍｕｃｈａｔｔｅｎｔｉｏｎｂｅｃａｕｓｅｏｆｔｈｅｉｒｉｎｔｅｒｅｓｔｉｎｇｐｈｙｓｉ ｃａｌｐｒｏｐｅｒｔｉｅｓｓｕｃｈａｓｅｌｅｃｔｒｉｃａｌｃｏｎｄｕｃｔｉｖｉｔｙ ,ｍａｇ ｎｅｔｉｓｍ ,ｎｏｎｌｉｎｅａｒｏｐｔｉｃａｌｐｒｏｐｅｒｔｉｅｓａｎｄｐｏｔｅｎｔｉａｌａｐｐｌｉ ｃａｔｉｏｎｓｉｎｓｅｐａｒａｔｉｏｎａｎｄｃａｔａｌｙｓｔ.1Ｔｈｅｍｏｄｕｌａｒａｐ ｐｒｏａｃｈ…     

1,2-Dimethyl-3,5-dioxopyrazolidin und seine Kondensations-produkte mit Aldehyden

Zusammenfassung 1,2-Dimethyl-3,5-dioxopyrazolidin wird durch direkte Umsetzung von Malonsäuredimethylester und sym-Dimethylhydrazin erhalten. Kondensation dieser Verbindung mit aliphatischen und aromatischen Aldehyden liefert elektrisch neutrale organische Lewissäuren, die in bezug auf die UV-Absorption weitestgehend den entsprechenden cyclischen Isopropylidenacylalen von Alkylund Aryl-methylenmalonsäuren gleichen.1,2-Dimethyl-3,5-pyrazolidinedione obtained directly from dimethyl malonate and sym.-dimethylhydrazine. Condensation with aliphatic and aromatic aldehydes leads to electrically neutral organic Lewis acids. Their UV-spectra are similar to those of the corresponding cyclic isopropylidene acylals of substituted malonic acids.Herrn Prof. Dr.Leopold Schmid zum 70. Geburtstag gewidmet.     

Synthesis and structure of dihydro-1,2,4-triazin-6(1H) ones

Reactions of the iminoesters 3a-c with hydrazine or 1,2-dimethylhydrazine gave 4,5-dihydro- 4a-c or 2,5-dihydro-1,2,4-triazin-6(1H) ones 7a-c , respectively. When methylhydrazine was employed, 1-methyl-4, 5-dihydro- 5a-c and 2-methyl-2,5-dihydro-1,2,4-triazin-6(1H) ones 6a-c were obtained. Compounds 6a-c exist as zwitterions in the solid state and in polar aprotic solvents.     

Complex formation of hydronium ion with several crown ethers in 1,2-dichloroethane,acetonitrile, and nitrobenzene solutions

A conductance study concerning the interaction between hydronium ion and several crown ethers in acetonitrile, nitrobenzene and 1,2-dichloroethane solutions has been carried out at 25°C. The stability constants of the resulting 1:1 complexes in acetonitrile and nitrobenzene solutions were determined from the molar conductance-mole ratio data and found to vary in the order 18C6>DB30C10>DC18C6>DB18C6>DB21C7>DB24C8>B15C5. In 1,2-dichloroethane solution, the complexation process results in the dissociation of ion pairs. There is an inverse relationship between the stabilities of the complexes and the Gutmann donicity of the solvents. In nitrobenzene solution, some evidence for the formation of a 2:1 sandwich adduct between the smaller crowns (i.e., B15C5 and 18-crowns) are observed from the molar conductance-mole ratio data which is supported by the¹H NMR data.     

Effect of the 18-crown-6 and benzo-18-crown-6 on the solvent extraction and separation of lanthanide(III) ions with 8-hydroxyquinoline

The synergistic solvent extraction of 13 lanthanides with mixtures of 8-hydroxyquinoline (HQ) and the crown ethers (S) 18-crown-6 (18C6) or benzo-18-crown-6 (B18C6) in 1,2-dichloroethane has been studied. The composition of the extracted species has been determined as LnQ₃ · S. The values of the equilibrium constant and separation factor have been calculated. Here, the effect of the synergistic agent (18C6 or B18C6) on the extraction process is discussed.     

Complexation study of dibenzo-18-crown-6 with UO2 2+ cation in binary mixed non-aqueous solutions

The complexation reaction of macrocyclic ligand, dibenzo-18-crown-6 (DB18C6) with UO₂ ²⁺ cation was studied in ethylacetate-1,2-dichloroethane (EtOAc/DCE), acetonitrile-1,2-dichloroethane (AN/DCE), methanol-1,2-dichloroethane (MeOH/DCE) and ethanol-1,2-dichloroethane (EtOH/DCE) binary solutions at different temperatures using the conductometric method. The conductance data show that the stoichiometry of the complex formed between DB18C6 and UO₂ ²⁺ cation is affected by the nature of the solvent systems. A non-linear behaviour was observed for changes of log K _f of (DB18C6.UO₂)⁺² complex versus the composition of the binary mixed solvents. The values of thermodynamic quantities (?S°_c, ?H°_c) for formation of (DB18C6.UO₂)⁺² complex were obtained from temperature dependence of the stability constant using the van’t Hoff plots. The results show that in most cases, the complex is enthalpy stabilized and in all cases entropy stabilized and both parameters are affected by the nature and composition of the mixed solvents. In addition, the complex formation between dicyclohexyl-18-crown-6 (DCH18C6) and UO₂ ²⁺ cation was studied in pure AN and the results were compared with those of the (DB18C6.UO₂)⁺² complex.     

Modification of sulfate lignin with sodium periodate to obtain sorbent of 1,1-dimethylhydrazine

Application of the oxidative modification of sulfate kraft lignin with sodium periodate under mild conditions is suggested in order to obtain a sorbent for detoxication of spillage places of rocket fuels based on 1,1-dimethylhydrazine and to purify wastewaters containing this compound. It was found that processing with the periodate at a temperature of 55°C for 20 h results in a more than twofold increase in the content of carbonyl and quinone groups in a lignin preparation and a rise in its polydispersity due to the appearance of a macromolecular condensed fraction and a threefold increase in the sorption capacity for 1,1-dimethylhydrazine. The sorbent can bind 6.7% of 1,1-dimethylhydrazine and substantially surpasses in this parameter other lignin-based sorbents. It was shown that the firm chemical binding of hydrazines hinders desorption of the highly toxic rocket propellant and products of its oxidative transformation from the surface of lignin both into solution and into the vapor phase, thereby providing safe handling of the spent sorbent.