503-27-5Relevant academic research and scientific papers
MODELISATION GENERALE DES PROCESSUS REACTIONNELS INTERVENANT AU COURS DE LA SYNTHESE DE LA DIMETHYLHYDRAZINE ASYMETRIQUE PAR LE PROCEDE RASCHIG. QUANTIFICATION DES PRODUITS DE DEGRADATION (HYDRAZONE). I. FORMULATION DU MODELE. VALIDITE EN MILIEU DILUE. INTERPRETATION
Delalu, H.,Marchand, A.
, p. 2149 - 2162 (2007/10/02)
A kinetic model of Unsymetrical dimethylhydrazine (UDMH) formation by Raschig process has been established.Its application range runs from pH = 8 to 14.64 (4 mol.l-1 NaOH).The synthesis is controlled by the acid-base dissociation equilibria : (NH2Cl NHCl- + H+; (CH3)2NH2(+) (CH3)2NH + H+; (CH3)2NHNH2+ (CH3)2NNH2 + H+) and by the following elementary reactions : -Dimethylhydrazine elaboration molecular (NH2Cl / (CH3)2NH) and ionic (NHCl- / (CH3)2NH) processes -Dimethylchloramine formation from NH2Cl and (CH3)2NH2+ -UDMH catalytic oxidation by NH2Cl and dimethyldiazene (CH3)2N+=N- intermediate formation -Diazene decomposition to yield formaldehyde dimethylhydrazone (FDMH) -Degradation of (CH3)2N+=N- by NH2Cl -Alkaline hydrolysis of chloramine.The synthesis can be expressed by a differential system of which the integration allows to foresee the evolution of mixtures in terms of concentration, pH and temperature.In particular, it allows a numeric evaluation of FDMH, troublesome by-product of the UDMH manufacture.Significant examples selected in different pH ranges and concentration have permitted to test the coherence between experimental and calculated curves.
Gasphase Reactions, 61. - Cycloalkanimines 2H-Azirine, 1-Azetidine, 1-Pyrroline, 1-Piperideine, and 3,4,5,6-Tetrahydro-2H-azepine: Preparation and Photoelectron Spectra
Bock, Hans,Dammel, Ralph
, p. 1971 - 1986 (2007/10/02)
For preparation of the easily oligomerizing cycloalkanimines , the following gasphase reactions are optimized PE spectroscopically: for the three membered ring imine, 2H-azirine, the heterogeneous KOR dehydrochlorination of the 2-chloroethyl azide preceding the thermolysis of the resulting vinyl azide, and for the lager rings, 1-azetine (n=2), 1-pyrroline (n=3), 1-piperideine (n=4) as well as the seven-membered 3,4,5,6-tetrahydro-2H-azepine, the consecutive chlorination of the corresponding cycloalkylamine over solid N-chlorosuccinimide followed by KOR dehydrochlorination of the N-chloro derivative formed.The PE spectra of all cyclic alkanimines prepared are assigned based on geometry-optimized MNDO calculations, and their electronic structures are discussed by molecular state comparison with increasing ring size and with the isoelectronic series of the cycloalkenes.The thermal ring opening of 1-azetine to 2-azabutadiene is investigated by PE spectroscopic real-time gas analysis; its ionization pattern is assigned by comparison with other azabutadienes.
CINETIQUE DE LA REACTION D'OXYDATION DE LA DIMETHYLHYDRAZINE ASYMETRIQUE (U.D.M.H.) PAR L'OXYGENE EN SOLUTION AQUEUSE ET EN MILIEU REDUCTEUR MONOPHASIQUE
Delalu, Henri,Marchand, Alain
, p. 149 - 156 (2007/10/02)
The kinetics of unsymetrical dimethylhydrazine (UDMH) oxidation by oxygen has been investigated in aqueous solution and reducing medium (excess of UDMH) in terms of concentration (O2 -4 mol*l-1) of pH between 12 to 13.9 and the temperature in the range of 15 to 35 deg C.The experiments have been carried out in a monophasic medium and under conditions in which the reactional process is homogeneous.First order in both reagents, the reaction is base catalysed and the rate bimolecular constant is a linear function of hydroxyde ions activity.The major products of the oxidation are formaldehyde hydrazone and formaldehyde dimethylhydrazone.We do not observe in those experimental conditions gaseous formation.An elaborate kinetics model, assuming that the reaction is performed in two successive steps, one specific to the oxidizing agent the other independent, allows us to explain the phenomena observed.
