Theoretical calculations of silica supported Mo2(η3-C3H5)4 species

Abstract:

Two models are studied for the anchored system Mo<inf>2</inf>(η³-C <inf>3</inf>H<inf>5</inf>)<inf>4</inf>/SiO<inf>2</inf>: united model (UM) and separated model (SM). Total energies, bond orders, diatomic energies, and parametric diatomic binding energies of selected bonds were calculated for Si<inf>8</inf>O<inf>24</inf>H<inf>16</inf>, Mo<inf>2</inf>(η³-C<inf>3</inf>H<inf>5</inf>)<inf>4</inf>, and Mo<inf>2</inf>(η³-C<inf>3</inf>H<inf>5</inf>) <inf>4</inf>/Si<inf>8</inf>O<inf>24</inf>H<inf>16</inf> systems, using a CNDO-UHF parametrical method. From the energetic viewpoint, UM is more stable than SM to explain the immobilizing of Mo<inf>2</inf>(η³-C<inf>3</inf>H<inf>5</inf>)<inf>4</inf> on silica. It is observed Mo-H interaction that leads to C-H activation. These results support several features of the generally accepted mechanism for olefin metathesis. An interpretation of these theoretical results was carried by comparing with PAS-FTIR, ¹H and ¹³C solid-state NMR, and XPS trends. © 2003 Elsevier Science B.V. All rights reserved.

Año de publicación:

2003

Keywords:

• Anchored complex
• Parametric method
• Metathesis
• Mo -allyl catalyst 2
• CNDO-UHF
• Mo2-allyl catalyst

Fuente:

scopus