The mechanism of hexamethylenetetramine (HMT) formation in the solid state at low temperature - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Physical Chemistry Chemical Physics Année : 2012

The mechanism of hexamethylenetetramine (HMT) formation in the solid state at low temperature

Résumé

There is convincing evidence that the formation of complex organic molecules occurred in a variety of environments. One possible scenario highlights the universe as a giant reactor for the synthesis of organic complex molecules, which is confirmed by numerous identifications of interstellar molecules. Among them, precursors of biomolecules are of particular significance due to their exobiological implications, and some current targets concern their search in the interstellar medium as well as understanding the mechanisms of their formation. Hexamethylenetetramine (HMT, C6H12N4) is one of these complex organic molecules and is of prime interest since its acid hydrolysis seems to form amino acids. In the present work, the mechanism for HMT formation at low temperature and pressure (i.e. resembling interstellar conditions) has been determined by combining experimental techniques and DFT calculations. Fourier transform infra-red spectroscopy and mass spectrometry techniques have been used to follow experimentally the formation of HMT as well as its precursors from thermal reaction of NH3:H2CO:HCOOH and CH2NH:HCOOH ice mixtures, from 20 K to 330 K. DFT calculations have been used to compute the mechanistic steps through which HMT can be formed starting from the experimental reactants observed in solid phase. The fruitful interplay between theory and experiment has allowed establishing that the mechanism in the solid state at low temperature is different from the one proposed in liquid phase, in which a new intermediate (1,3,5-triazinane, C3H9N3) has been identified. In the meantime, aminomethanol has been unambiguously confirmed as the first intermediate whereas the hypothesis of methylenimine as the second is further strengthened.

Domaines

Chimie
Fichier non déposé

Dates et versions

hal-01457957 , version 1 (06-02-2017)

Identifiants

Citer

Vassilissa Vinogradoff, Albert Rimola, Fabrice Duvernay, Grégoire Danger, Patrice Theulé, et al.. The mechanism of hexamethylenetetramine (HMT) formation in the solid state at low temperature. Physical Chemistry Chemical Physics, 2012, 14 (35), pp.12309--12320. ⟨10.1039/c2cp41963g⟩. ⟨hal-01457957⟩

Collections

CNRS UNIV-AMU PIIM
75 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More