Theoretical Investigation of the Methanol Decomposition by Fe+)and Fe(C2H4)+: A π-Type Ligand Effect.
J Phys Chem A
; 119(40): 10204-11, 2015 Oct 08.
Article
em En
| MEDLINE
| ID: mdl-26377371
ABSTRACT
Density functional theory has been used to probe the mechanism of gas-phase methanol decomposition by bare Fe(+) and ligated Fe(C(2)H(4))(+) in both quartet and sextet states. For the Fe(+)/methanol system, Fe(+) could directly attach to the O and methyl-H atoms of methanol, respectively, forming two encounter isomers. The methanol reaction with Fe(+) prefers initial C-O bond activation to yield methyl with slight endothermicity, whereas CH(4) elimination is hindered by the strong endothermicity and high-energy barrier of hydroxyl-H shift. For the Fe(C(2)H(4))(+)/methanol system, the major product of H(2)O is formed through six elementary steps:
encounter complexation, C-O bond activation, C-C coupling, ß-H shift, hydride H shift, and nonreactive dissociation. Both ligand exchange and initial C-O bond activation mechanisms could account for ethylene elimination with the ion products Fe(CH(3)OH)(+) and (CH(3))Fe(OH)(+), respectively. With the assistance of a π-type C(2)H(4) ligand, the metal center in the Fe(C(2)H(4))(+)/CH(3)OH system avoids formation of unfavorable multi-σ-type bonding and thus greatly enhances the reactivity compared to that of bare Fe(+).
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Teoria Quântica
/
Metanol
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Etilenos
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Ferro
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article