The C--H Activation of Methane by Laser-Ablated Zirconium Atoms: CH=ZrH, the Simplest Carbene Hydride Complex, Agostic Bonding, and (CH)ZrH.

Reaction of laser-ablated Zr with CH (CH, CD, and CHD) in excess neon during condensation at 5 K forms CH == ZrH, the simplest alkylidene hydride complex, which is identified by infrared absorptions at 1581.0, 1546.2, 757.0, and 634.5 cm. Density functional theory electronic structure calculations u...

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Detalles Bibliográficos
Publicado en:Journal of the American Chemical Society Vol. 127; no. 1; pp. 465 - 474
Autores principales: Han-Gook Cho, Xuefeng Wang, Andrews, Lester
Formato: Artículo
Publicado: American Chemical Society 1/12/2005
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Acceso en línea:Ver este registro en EBSCOhost
Descripción
Sumario:Reaction of laser-ablated Zr with CH (CH, CD, and CHD) in excess neon during condensation at 5 K forms CH == ZrH, the simplest alkylidene hydride complex, which is identified by infrared absorptions at 1581.0, 1546.2, 757.0, and 634.5 cm. Density functional theory electronic structure calculations using a large basis set with polarization functions predict a C symmetry structure with agostic C--H- - -Zr bonding and distance of 2.300 Å. Identification of the agostic CH == ZrH methylidene complex is confirmed by an excellent match of calculated and observed isotopic frequencies particularly for the four unique CHD==ZrHD isotopic modifications. The analogous reactions in excess argon give two persistent photoreversibie matrix configurations for CH==ZrH. Finally, methane activation by, CH==ZrH gives the new (CH)ZrH molecule.