Εξειδίκευση τύπου :	Άρθρο σε επιστημονικό περιοδικό
Τίτλος:	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
Δημιουργός/Συγγραφέας:	Papayannis D.K. Papavasileiou K.D. Melissas V.S.
Εκδότης:	Elsevier
Ημερομηνία:	2016
Γλώσσα:	Αγγλικά
ISSN:	1387-1811
DOI:	10.1016/j.micromeso.2015.12.034
Περίληψη:	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.
Τίτλος πηγής δημοσίευσης:	Microporous and Mesoporous Materials
Τόμος/Κεφάλαιο:	226
Σελίδες:	1-9
Θεματική Κατηγορία:	[EL] Χημεία (Γενικά)[EN] Chemistry (General)
Λέξεις-Κλειδιά:	Alkyl bromides Bromine atom transfer Density functional theory H-FAU zeolite ONIOM
Αξιολόγηση από ομότιμους (peer reviewed):	Ναι
Κάτοχος πνευματικών δικαιωμάτων:	© 2015 Elsevier Inc. All rights reserved.
Εμφανίζεται στις συλλογές:	Ινστιτούτο Χημικής Βιολογίας - Επιστημονικό έργο