Thermal decomposition pathways of hydroxylamine: theoretical investigation on the initial steps.
نویسندگان
چکیده
Hydroxylamine (NH(2)OH) is an unstable compound at room temperature, and it has been involved in two tragic industrial incidents. Although experimental studies have been carried out to study the thermal stability of hydroxylamine, the detailed decomposition mechanism is still in debate. In this work, several density functional and ab initio methods were used in conjunction with several basis sets to investigate the initial thermal decomposition steps of hydroxylamine, including both unimolecular and bimolecular reaction pathways. The theoretical investigation shows that simple bond dissociations and unimolecular reactions are unlikely to occur. The energetically favorable initial step of decomposition pathways was determined as a bimolecular isomerization of hydroxylamine into ammonia oxide with an activation barrier of approximately 25 kcal/mol at the MPW1K level of theory. Because hydroxylamine is available only in aqueous solutions, solvent effects on the initial decomposition pathways were also studied using water cluster methods and the polarizable continuum model (PCM). In water, the activation barrier of the bimolecular isomerization reaction decreases to approximately 16 kcal/mol. The results indicate that the bimolecular isomerization pathway of hydroxylamine is more favorable in aqueous solutions. However, the bimolecular nature of this reaction means that more dilute aqueous solution will be more stable.
منابع مشابه
Electrochemistry, Thermalanalysis, and Theoretical Study of Vanadyl Schiff Base Complexes
The VO(IV) complexes of tridentate ONO Schiff base ligands derived from 2- aminobenzoicacid and salicylaldehyde derivatives were synthesized and characterized by IR, UV–Vis and elemental analysis. Electrochemical properties of the vanadyl complexes were investigated by cyclic voltammetry. A good linear correlation was observed between the oxidation potentials and the electron-withdrawing charac...
متن کاملThermal Runaway Reaction Hazard and Decomposition Mechanism of the Hydroxylamine System
Thermal Runaway Reaction Hazard and Decomposition Mechanism of the Hydroxylamine System. (August 2005) Chunyang Wei, B.E., Dalian University of Technology; M.S., University of Tulsa Chair of Advisory Committee: Dr. M. Sam Mannan Chemical reactivity hazards have posed a significant challenge for industries that manufacture, store, and handle reactive chemicals. Without proper management and cont...
متن کاملSynthesis and investigation the thermal behavior thermodynamically of new metal Complex of Cobalt nitrate
Increasing the molecular accumulation and density of high-energy substances have a determinative role in improving the performance and intensity of energy release. Therefore, it is possible to increase the density of high-energy materials if the high-energy molecules can be arranged around a metal core as coordinated molecules. The aim of this project was to synthesize energetic complexes of cy...
متن کاملUnimolecular decomposition of 2,5-dimethylfuran: a theoretical chemical kinetic study.
The unimolecular decomposition of 2,5-dimethylfuran (DMF), a promising next-generation biofuel, was studied at the CBS-QB3 level of theory. As most of its decomposition routes remain unknown, a large number of pathways were explored: initial C-H bond fission, biradical ring opening, H-atom and CH(3)-group transfers involving carbene intermediates. Based on the computed potential energy surfaces...
متن کاملMechanistic and spectroscopic identification of initial reaction intermediates for prenal decomposition on a platinum model catalyst.
The prediction of a reaction mechanism and the identification of the corresponding chemical intermediates is a major challenge in surface science and heterogeneous catalysis, due to a complex network of elementary steps and surface species. Here we demonstrate how to overcome this difficulty by tracking the temperature dependent formation of the initial reaction intermediates and identifying th...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The journal of physical chemistry. A
دوره 114 34 شماره
صفحات -
تاریخ انتشار 2010