1. Home page
  2. Search

Investigation of bromine atom transfer mechanism from an alkyl bromide molecule to an O-bonded alkyl group in a FAU zeolite by the ONIOM method

This item is provided by the institution :
Εθνικό Ίδρυμα Ερευνών (ΕΙΕ)   

Repository :
Ήλιος - Αποθετήριο Εθνικού Ιδρύματος Ερευνών  | repositories EKT   

see the original item page
in the repository's web site and access all digital files if the item*



Investigation of bromine atom transfer mechanism from an alkyl bromide molecule to an O-bonded alkyl group in a FAU zeolite by the ONIOM method
Papavasileiou K.D.
Papayannis D.K.
Melissas V.S.
Άρθρο σε επιστημονικό περιοδικό
2016
The details of the bromine atom transfer mechanism from an ethyl bromide molecule to an O-bonded alkyl group, attached to the FAU zeolite wall, were elucidated, by means of Quantum Mechanical and Molecular Mechanical (QM/MM) calculations. The investigation of this mechanism has been established on the 84T model cluster of faujasite zeolite with the help of the ONIOM approach, utilizing three-layer ONIOM3(B3LYP/6-31 + G(d,p):HF/6-31G:UFF), ONIOM3(M06-2X/6-31 + G(d,p):HF/6-31G:UFF) and ONIOM3(MP2(full)/6-31 + G(d,p):HF/6-31G:UFF) schemes. Our results indicate that the reaction proceeds via a ring structure formation path, where the ethyl bromide molecule is strongly attracted to both the alkyl group and the nearby Si bridging lattice O atom. Interaction energies for the O-bonded alkyl (ethyl or isopropyl) group linked to an ethyl bromide molecule in a FAU pore according to the ONIOM3(MP2(full)/6-31+G(d,p):HF/6-31G:UFF) calculation are approximately -18.3 and -19.3 kcal mol-1, respectively. In addition, at the same level of theory, the bromine atom shift from the ethyl bromide molecule to the adjacent O-bonded ethyl or isopropyl group, forming a new alkyl bromide and a new ethyl radical, are characterized by an activation barrier of 25.1 and 17.9 kcal mol-1, respectively, relative to the reagent complex.
Χημεία (Γενικά) (EL)
Chemistry (General) (EN)
ONIOM (EN)
H-FAU zeolite (EN)
Bromine atom transfer (EN)
Alkyl bromides (EN)
Density functional theory (EN)
English
Elsevier
Microporous and Mesoporous Materials
© 2015 Elsevier Inc. All rights reserved.
© 2015 Elsevier Inc. All rights reserved. (EN)
Εθνικό Ίδρυμα Ερευνών (ΕΙΕ)
Ήλιος - Αποθετήριο Εθνικού Ιδρύματος Ερευνών



*Institutions are responsible for keeping their URLs functional (digital file, item page in repository site)