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PubMed1988

Toxicity assessment of hydrazine fuels.

The major health aspects of exposure to hydrazine propellants are reviewed. Toxic effects of hydrazine fuels on humans and animals as well as in vitro studies are discussed with emphasis on recent findings and USAF studies. Propellant hydrazines have been found to be genotoxic in in vitro studies and oncogenic in animal studies. Embryotoxicity has been demonstrated at very high exposures but not at occupationally encountered levels for hydrazine and unsymmetrical dimethylhydrazine. Epidemiologic evidence to support these findings is lacking; however, the results of animal and in vitro studies have resulted in lowering both the time-weighted average-threshold limit values and short-term exposure limits for these propellants.

Aerospace Medicine↗

PubMedDate not supplied

[Hydrazine derivative modification of the activity of brain mitochondrial monoamine oxidases].

Treatment of bovine brain stem mitochondria with hydrazine derivatives, which inhibited the monoamine oxidase activity (substrate: 5-hydroxytryptamine), was accompanied by appearance of the properties to deaminate histamine and cadaverine at a high rate. The same phenomenon was observed in vivo after treatment of mice with the hydrazine derivatives. The dramatic increase in histamine deaminating activity in brain was accompanied by a decrease in the tissue concentration of histamine. The hydrazine derivatives are considered as prooxidants stimulating via a free-radical mechanism lipid peroxidation in methyloleate solutions and in biomembranes (ref. 5) and causing qualitative alteration (transformation) in catalytic properties of monoamine oxidases of the tyre A, which acquire the histamine deaminating activity. A certain correlation was noted between the prooxidant effect of the hydrazine derivatives and the modification of catalytic properties of the membrane bound monoamine oxidases of brain mitochondria in vitro and in vivo.

Animals↗

PubMed2002

Air monitoring of aldehydes by use of hydrazine reagents with a triazine backbone.

Two hydrazine reagents, 4- N, N-dimethylamino-6-(4'-methoxy-1'-naphthyl)-1,3,5-triazine-2-hydrazine (DMNTH) and N-methyl-4- N', N'-dimethylamino-6-(4'-methoxy-1'-naphthyl)-1,3,5-triazine-2-hydrazine (MDMNTH) have been synthesized and used for the determination of aldehydes in air samples. Test tubes with the reagents coated on silica gel were prepared and used for monitoring of carbonyls in air. After elution with acetonitrile the hydrazones formed were separated by reversed-phase liquid chromatography. Detection was performed by UV-visible and fluorescence spectroscopy. The results were validated by use of standard atmospheres of the carbonyls and of nitrogen dioxide and ozone, as potential interferents. In comparison with established hydrazine reagents, e.g. 2,4-dinitrophenylhydrazine (DNPH), the results from use of MDMNTH correlate well; lower recoveries were obtained by use of DMNTH. The limits of detection for the new reagents are superior to those for DNPH, because of the possibility of fluorescence detection.

Journal Article↗

PubMed1983

EPR study on the interaction of spin-labelled hydrazine mustard derivatives with DNA.

The interaction of three spin-labelled compounds, derivatives of bis-(2-chloroethyl)-hydrazine (HMSL), N-methyl,N-chloroethyl-hydrazine (MCEHSL) and bis-(2-bromoethyl)-hydrazine (BEHSL) with DNA was studied by the method of electron paramagnetic resonance (EPR). It was found that HMSL (containing two chloroethyl groups) and MCEHSL (containing one chloroethyl group) gave spin-labelled dsDNA with identical strongly immobilized EPR spectra. The conclusion was drawn that only one of the alkylating groups of HMSL reacted with DNA. In contrast, the EPR spectrum of DNA spin-labelled with BEHSL was non-immobilized due to the strong destabilizing effect of this compound on the double helix. The extent of alkylation of DNA with the three hydrazine mustard derivatives was one and the same. It was found, however, that chloroethyl-containing derivatives (HMSL and MCEHSL) had an expressed base specificity and alkylated preferably the guanilic residues, and their bromo-analogue (BEHSL) did not show any base specificity and alkylated the bases of DNA at random.

Alkylation↗

PubMed2006

Study of nickel nanoparticles supported on activated carbon prepared by aqueous hydrazine reduction.

Nickel nanoparticles were obtained by the reduction in hydrazine aqueous media of nickel acetate as a precursor supported on activated carbon of high surface area. Classical catalysts using nickel acetate or nitrate were prepared for comparison. The catalysts were characterized by N(2) physisorption, H(2)-TPR, H(2)-adsorption, TPD, TEM, and XRD, and tested in the gas phase hydrogenation of benzene. Hydrazine catalysts were found much more active in benzene hydrogenation than corresponding classically prepared catalysts. Remarkably, their reactivity is comparable (turn-over frequency of 0.2001-0.2539 s(-1) at 393 K) to that of Pt classical catalysts supported on activated carbon in the same conditions. Evidence is given for the existence of the hydrogen spillover effect in benzene hydrogenation, not reported before in the literature. As a result of the hydrogen spillover effect, catalysts performances can be explained by a combination of surface metal atom reactivity, metal-support interaction strength, and specific surface area extent. Maximum effect is observed with hydrazine preparation method, for 1% Ni content and nickel acetate as a precursor. Unexpectedly, it was also found that hydrazine preparation increases the specific area of the catalysts.

Journal Article↗

PubMed2001

A Novel Hydrazine Linker Resin and Its Application for the Solid-Phase Synthesis of alpha-Branched Primary Amines.

A novel hydrazine linker resin for solid-phase organic synthesis has been developed. Starting from Merrifield resin, the new N-butyl-N-methylpolystyrene-hydrazine linker is prepared in three steps. Polymer-supported hydrazones, readily prepared from aldehydes and the hydrazine resin, react with alkyl- and arylorganolithium reagents under 1,2-addition to the C-N double bond to afford the corresponding hydrazines. Release from solid support was achieved by reductive N-N bond cleavage using the borane-tetrahydrofuran complex. The resulting alpha-branched primary amines were protected as their amides or carbamates, respectively, and, after purification, were obtained in good overall yields and in high purity (12 examples).

Journal Article↗

PubMed2000

Ruthenium(II) ammine and hydrazine complexes with [N(Ph2PQ)2]- (Q = S, Se) ligands.

Reactions of coordinatively unsaturated Ru[N(Ph2PQ)2]2(PPh3) (Q = S (1), Se (2)) with pyridine (py), SO2, and NH3 afford the corresponding 18e adducts Ru[N(Ph2PQ)2]2(PPh3)(L) (Q = S, L = NH3 (5); Q = Se, L = py (3), SO2 (4), NH3 (6)). The molecular structures of complexes 2 and 6 are determined. The geometry around Ru in 2 is pseudo square pyramidal with PPh3 occupying the apical position, while that in 6 is pseudooctahedral with PPh3 and NH3 mutually cis. The Ru-P distances in 2 and 6 are 2.2025(11) and 2.2778(11) A, respectively. The Ru-N bond length in 6 is 2.185(3) A. Treatment of 1 or 2 with substituted hydrazines L or NH2OH yields the respective adducts Ru[N(Ph2PQ)2]2(PPh3)(L) (Q = S, L = NH2NH2 (12), t-BuNHNH2 (14), l-aminopiperidine (C5H10NNH2) (15); Q = Se, L = PhCONHNH2 (7), PhNHNH2 (8), NH2OH (9), t-BuNHNH2 (10), C5H10NNH2 (11), NH2NH2 (13)), which are isolated as mixtures of their trans and cis isomers. The structures of cis-14 and cis-15 are characterized by X-ray crystallography. In both molecular structures, the ruthenium adopts a pseudooctahedral arrangement with PPh3 and hydrazine mutually cis. The Ru-N bond lengths in cis-14.CH2Cl2 and cis-15 are 2.152(3) and 2.101(3) A, respectively. The Ru-N-N bond angles in cis-14.CH2Cl2 and cis-15 are 120.5(4) and 129.0(2) degrees, respectively. Treatment of 1 with hydrazine monohydrate leads to the isolation of yellow 5 and red trans-Ru[N(Ph2PS)2]2(NH3)(H2O) (16), which are characterized by mass spectrometry, 1H NMR spectroscopy, and elemental analyses. The geometry around ruthenium in 16 is pseudooctahedral with the NH3 and H2O ligands mutually trans. The Ru-O and Ru-N bond distances are 2.118(4) and 2.142(6) A, respectively. Oxidation reactions of the above ruthenium hydrazine complexes are also studied.

Journal Article↗

PubMed2004

Gas-phase kinetics and mechanism of the reactions of protonated hydrazine with carbonyl compounds. Gas-phase hydrazone formation: kinetics and mechanism.

The gas-phase reactions of protonated hydrazine (hydrazinium) with organic compounds were studied in a selected ion flow tube-chemical ionization mass spectrometer (SIFT-CIMS) at 0.5 Torr pressure and approximately 300 K and with hybrid density functional calculations. Carbonyl and other polar organic compounds react to form adducts, e.g., N(2)H(5)(+)(CH(3)CH(2)CHO). In the presence of neutral hydrazine, aldehyde adducts react further to form protonated hydrazones, e.g., CH(3)CH(2)CH[double bond]HNNH(2)(+) from propanal. Using deuterated hydrazine (N(2)D(4)) and butanal, we demonstrate that the gas-phase ion chemistry of hydrazinium and carbonyls operates by the same mechanisms postulated for the reactions in solution. Calculations provide insight into specific steps and transition states in the reaction mechanism and aid in understanding the likely reaction process upon chemical or translational activation. For most carbonyls, rate coefficients for adduct formation approach the predicted maximum collisional rate coefficients, k approximately 10(-9) cm(3) molecule(-1) s(-1). Formaldehyde is an exception (k approximately 2 x 10(-11) cm(3) molecule(-1) s(-1)) due to the shorter lifetime of its collision complex. Following adduct formation, the process of hydrazone formation may be rate limiting at thermal energies. The combination of fast reaction rates and unique chemistry shows that protonated hydrazine can serve as a useful chemical-ionization reagent for quantifying atmospheric carbonyl compounds via CIMS. Mechanistic studies provide information that will aid in optimizing reaction conditions for this application.

Journal Article↗

PubMed2005

Hydrazine decomposition over Irn/Al2O3 model catalysts prepared by size-selected cluster deposition.

Hydrazine decomposition chemistry was probed over a temperature range from 100 to 800 K for a series of model catalysts prepared by mass-selected Ir(n)(+) deposition on planar Al(2)O(3)/NiAl(110). Two sets of experiments are reported. Temperature-programmed desorption (TPD) was used to study hydrazine desorption and decomposition on Al(2)O(3)/NiAl(110) and on a model catalyst prepared by deposition of Ir(+) on Al(2)O(3)/NiAl(110) at a density large enough (5 x 10(14) cm(-2)) that formation of a distribution of small Ir(n) clusters on the surface is expected. This model catalyst was found to have hydrazine decomposition properties qualitatively similar to those observed on single-crystal Ir and polycrystalline Rh. This catalyst was also studied by X-ray photoelectron spectroscopy (XPS), to probe TPD-induced changes in the samples. A substantial decrease in the Ir XPS intensity suggests that considerable sintering takes place when the samples are heated to 800 K. In addition, a significant fraction of the nitrogen contained in the hydrazine is converted to an aluminum nitride (or mixed Al(x)O(y)N(z)) compound. Continuous flow experiments were used to probe relative reactivity at 300 and 400 K of samples prepared by depositing differently sized Ir(n)(+) clusters. At 300 K, samples prepared with preformed Ir(n)(+) (n = 5, 7, 10) are about twice as active, per Ir atom, as samples prepared with Ir(+) deposition, and there is a weaker trend to higher activity with increasing cluster size. At 400 K the trends are similar, but weaker, suggesting that thermal modification of the samples is already significant.

Journal Article↗

PubMed2005

Unusual structural and energetic features of homolytic bond dissociation: from tetrakis(disyl)diphosphine to tetrakis(di-tert-butylsilyl)hydrazine.

Quantum chemical calculations of the structures and thermodynamics of homolytic dissociation of the central P-P and N-N bonds in tetrakis(disyl)diphosphine and tetrakis(di-tert-butylsilyl)hydrazine have been performed. The theory predicted negative standard enthalpies for homolytic bond dissociation in both cases, -71.0 and -108.4 kJ mol(-1) for the diphosphine and hydrazine, respectively, using the ONIOM (MP2/6-31+G*:B3LYP/3-21G*) level. The dissociation is accompanied by considerable structural changes in the radicals as compared to the corresponding fragments of the parent molecules, resulting in low dissociation enthalpies. The most pronounced changes in both radicals are the relaxation of bond angles in the substituents and a conformational change in the orientation of the substituent groups. In addition, the bis(di-tert-butylsilyl)aminyl radical displays a considerable increase in Si-N-Si angle and shortening of the Si-N bonds upon dissociation. These changes are not associated with any appreciable delocalisation of the lone electron, as the spin density is found from the B3LYP/3-21G* calculations to be largely concentrated on the nitrogen atom. It has been also shown that although the dissociation energies are low for both compounds, the intrinsic energies of the central bonds are still high, 140.6 kJ mol(-1) for the P-P bond in tetrakis(disyl)diphosphine and 490.6 kJ mol(-1) for the N-N bond in tetrakis(di-tert-butylsilyl)hydrazine, using the ONIOM method. The calculations predict that the dissociation of tetrakis(disyl)diphosphine would have negative free energy even without taking relaxation of the fragments into account, while the full potential of releasing about 306 kJ mol(-1) of energy stored in the ligands of tetrakis(di-tert-butylsilyl)hydrazine is only fully realised upon a considerable separation of the fragments.

Journal Article↗

PubMedDate not supplied

Hydrazine-induced post-chemiluminescence phenomenon of permanganate-luminol reaction and its applications.

The post-chemiluminescence phenomenon arising from the permanganate-luminol reaction induced by hydrazine and isoniazid was investigated. When hydrazine or isoniazid was injected into the mixture after the end of the reaction of permanganate with alkaline luminol, a new chemiluminescence (CL) reaction was initiated and strong CL signal was detected. A possible CL mechanism is suggested, based upon the studies of the kinetic characteristics of the CL reaction, the UV-visible spectra, the CL spectra and some other experiments. The present reactions allow the determination of 0.1-10.0 mg/L hydrazine and 0.02-1.0 mg/L isoniazid, with detection limits of 0.03 mg/L and 0.006 mg/L, respectively. The method was applied to the determination of isoniazid in pharmaceutical preparations.

Antitubercular Agents↗

PubMed1976

Lung tumour incidence in mice treated with hydrazine sulphate.

Lung tumour incidence in mice fed with hydrazine sulphate (1.1 mg/day/mouse) was studied in male and female mice of Swiss, Strong "A" and F1 cross of ICRC (female) X C3H (Jax) (male), as well as in C17 males. Swiss strain mice showed 100% lung adenocarcinomas. None of the treated mice of different strains had liver tumours. Hydrazine sulphate also induced adenocarcinomas of lung in Strong "A" and F1 cross of ICRC females X C3H (Jax) males but it produced lymphomas of lung in C17 strain. Female mice of Swiss strain and F1 hybrids showed greater susceptibility to hydrazine sulphate than the males. It was interesting to observe that protein and vitamin B deficiency in the diet shortened the tumour induction period in Swiss strain mice.

Adenocarcinoma↗

PubMed1983

Hydrazine levels in formulations of hydralazine, isoniazid, and phenelzine over a 2-year period.

Hydrazine levels in formulations of hydralazine, isoniazid, and phenelzine have been measured over a 2-year period under ambient conditions and under temperature and humidity stress. Hydralazine tablets are stable under ambient conditions, but the hydrazine level in an injectable formulation increased from 4.5 to 10 micrograms/ml over a 23-month period. Isoniazid tablets are also stable, but hydrazine levels in an elixir and a pyridoxine combination product doubled to 44 micrograms/ml and 19 micrograms/tablet, respectively. Levels in phenelzine tablets appeared to remain constant at approximately 60 micrograms/tablet, with considerable tablet-to-tablet variation.

Drug Contamination↗

PubMed1993

Effects of two substituted hydrazine monoamine oxidase (MAO) inhibitors on neurotransmitter amines, gamma-aminobutyric acid, and alanine in rat brain.

Time- and dose-response analyses were undertaken to investigate the effects of the substituted hydrazine monoamine oxidase (MAO) inhibitors iproniazid and nialamide on the following: MAO-A and -B activity; levels of gamma-aminobutyric acid (GABA), alanine (ALA), and the neurotransmitter amines dopamine, noradrenaline, and 5-hydroxytryptamine (serotonin) and their acid metabolites; and the activity of GABA-transaminase and ALA-transaminase. The results showed that these drugs are relatively potent MAO inhibitors but, unlike the unsubstituted hydrazine MAO inhibitor phenelzine, they do not produce increased GABA and ALA levels in brain. These experiments suggest that a free hydrazine group is necessary for MAO inhibitors to also have marked effects on GABA and ALA.

Alanine↗

PubMed2006

Hydrazine determination in sludge samples by high-performance liquid chromatography.

A relatively simple and cost-effective method utilizing HPLC with UV detection was developed to detect and quantify hydrazine in sludge samples. The method was developed primarily for sludge samples, but it can also be applicable to soil and other environmental samples. The hydrazines in the matrices were derivatized to hydrazones with benzaldehyde. The hydrazones were separated using HPLC with an RP C-18 column in an isocratic mode with methanol-water (95:5 v/v) and detected with UV detection at 313 nm. The detection limit (25 microL injection) for the method is 0.02 microg/mL of hydrazine.

Benzaldehydes↗

PubMed1992

A biochemical and NMR spectroscopic study of hydrazine in the isolated rat hepatocyte.

Using isolated rat hepatocytes the biochemical effects of hydrazine have been investigated using both conventional assay techniques and high resolution proton NMR. High resolution proton NMR revealed that hydrazine caused a significant increase in alanine and lactate levels in the incubation buffer, whereas levels of beta-hydroxybutyrate were decreased. NMR also detected metabolites of hydrazine notably acetylhydrazine and a cyclised hydrazone formed with alpha-ketoglutarate. Changes were detected in NADH and NADPH, ATP, succinate dehydrogenase (SDH) and total non-protein sulphydryl groups (TNPSH). However, the changes in pyridine nucleotides occurred at higher concentrations than those affecting succinate dehydrogenase and ATP. Similarly, the depletion of TNPSH occurred at a higher concentration and with a different time course to that seen with ATP depletion and inhibition of succinate dehydrogenase.

Adenosine Triphosphate↗

PubMed1994

Influence of inducers and inhibitors of cytochrome P450 on the hepatotoxicity of hydrazine in vivo.

Hydrazine hepatotoxicity in vivo, as manifested by triglyceride accumulation, depletion of ATP and reduced glutathione (GSH) was shown to be dose related. The effect of pretreatment of rats with various inhibitors and inducers of cytochrome P450 on these dose-response relationships was investigated. Pretreatment with the inhibitor piperonyl butoxide increased triglyceride accumulation whereas pretreatment with the inducers phenobarbital and beta-naphthoflavone (BNF) resulted in reduced triglyceride accumulation. Pretreatment with the inducers acetone and isoniazid also enhanced triglyceride accumulation. Only phenobarbital pretreatment also significantly reduced GSH and ATP depletion. A linear correlation was found between hepatic glutathione and ATP levels in non-pretreated animals given various doses of hydrazine. However, exponential relationships were found between hepatic triglycerides and both hepatic ATP and glutathione. The results suggest that i) the hepatotoxicity of hydrazine can be modulated by inducing or inhibiting particular isoenzymes of cytochrome P450, ii) ATP and GSH depletion may not be directly involved in the development of fatty liver.

Acetone↗

PubMed1983

Lupus erythematosus-like disease due to hydrazine.

A case of systemic lupus erythematosus-like disease due to occupational exposure to hydrazine is described. The patient had four of the 1982 revised criteria for SLE (malar rash, photosensitivity, antinuclear antibody, and antibody to nDNA) and genetically is a slow acetylator with the HLA DR2,3 phenotype. Many of her healthy family members had antibodies to nuclear constituents. Lymphocytes from the patient and an identical twin sister, but not from three normal control subjects, showed inhibition of pokeweed mitogen-stimulated IgG synthesis after five daily exposures of each subject to hydrazine. Chemicals such as hydrazine in the environment can induce cases of SLE-like disease in predisposed persons.

Adult↗