|
Structural, Redox and Spectrometric Characterization of Energetic Material FOX-7 (2,2-dinitroethene-1,1-diamine) in Solution
Šimková, Ludmila ; Ludvík, Jiří
The investigation of energetic materials, especially organic nitro-amino-derivatives, always has attracted attention of physical chemists. However, published articles demonstrate lack of systematic study of molecules based on aliphatic backbones, rather than aromatic structures. This work represents the first systematic electrochemical and spectrometric characterization of 2,2-dinitroethene-1,1-diamine (FOX-7) in aqueous and aprotic solvent. Based on the results obtained from combination of electrochemistry with spectrometric methods, the actual structure of FOX-7 in various media was revealed, its reducibility described and radical intermediates as well as products were intercepted, isolated and characterized.
|
| |
|
FOX-7 - Study of Reduction Products of Spectroelectrochemical Methods
Šimková, Ludmila ; Dmitrieva, E. ; Klíma, Jiří ; Dunsch, L. ; Ludvík, Jiří
A new energetic material 2,2-dinitroethene-1,1-diamine (FOX-7) is recently broadly tested because of its high performance and very low sensitivity. On the other hand, its electrochemical and redox properties have not been studied yet. Our results show that FOX-7 is reduced in aprotic solvents only by two one-electron steps up to -2.9 V. The color changes during reduction of FOX-7 and reversibility of the redox process indicate the presence of radical intermediates. Therefore in situ UV-vis-NIR and ESR spectroelectrochemical investigations were performed. The products after exhaustive electrolyses were separated by HPLC and are identified by mass spectrometry. The possible formation of gaseous products was followed online EC-GC.
|
|
Electrochemical and spectrometric study of FOX-7 in aprotic solvents
Šimková, Ludmila ; Ludvík, Jiří ; Klíma, Jiří
2,2-Dinitroethene-1,1-diamine (FOX-7) is a recently developed and broadly tested energetic material with high efficiency and low sensitivity. Generally, explosion is based on thermally initiated chain of intramolecular redox reactions. Recently it has been found that electrochemical reduction in aqueous solutions is also able to provoke the chain of follow-up processes leading to total decomposition of the parent substance yielding gaseous products analogously like during explosion. Similarly, results from reductive electrolysis of FOX-7 in aprotic solvents show analogous course of degradation. The first transferred electron activates the molecule and initiated the formation of colored radical intermediates that have been spectroscopically characterized
|
|
Strange Redox Behavior of 1,1-Diamino-2,2-dinitroethene
Šimková, Ludmila ; Ludvík, Jiří ; Klíma, Jiří
The expected product of polarographic reduction of 1,1-diamino-2,2-dinitroethene (FOX-7) in aqueous buffered solutions is ethan-1,2-diamine. But exhaustive electrolysis did not show this product. The main products are gases. Due to combination of electrochemistry and GC and with MS analysis were found following gaseous products: N-2, NO, N2O, H2O. However, no carbon containing gaseous product was found. A part of products remains probably in the water solution as inorganic ions. The degradation process accompanying the exhaustive electrolysis seems to be analogous to the reactions during explosion, but under very low concentration, cooled and slowed down by the solvent.
|