Hydrogen Tunneling in Catalytic Hydrolysis and Alcoholysis of Silanes
[EN] An unprecedented quantum tunneling effect has been observed in catalytic Si-H bond activations at room temperature. The cationic hydrido-silyl-iridium(III) complex, {Ir[SiMe(o-C6H4SMe)(2)](H)(PPh3)(THF)}[BAr4F], has proven to be a highly efficient catalyst for the hydrolysis and the alcoholysis...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2022 |
| País: | España |
| Institución: | Universidad del País Vasco |
| Repositorio: | Addi. Archivo Digital para la Docencia y la Investigación |
| OAI Identifier: | oai:addi.ehu.eus:10810/57487 |
| Acceso en línea: | http://hdl.handle.net/10810/57487 |
| Access Level: | acceso abierto |
| Palabra clave: | homogeneous catalysis iridium quantum tunneling silanes |
| Sumario: | [EN] An unprecedented quantum tunneling effect has been observed in catalytic Si-H bond activations at room temperature. The cationic hydrido-silyl-iridium(III) complex, {Ir[SiMe(o-C6H4SMe)(2)](H)(PPh3)(THF)}[BAr4F], has proven to be a highly efficient catalyst for the hydrolysis and the alcoholysis of organosilanes. When triethylsilane was used as a substrate, the system revealed the largest kinetic isotopic effect (KIESi-H/Si-D=346 +/- 4) ever reported for this type of reaction. This unexpectedly high KIE, measured at room temperature, together with the calculated Arrhenius preexponential factor ratio (A(H)/A(D)=0.0004) and difference in the observed activation energy [(EaD -EaH )=34.07 kJ mol(-1)] are consistent with the participation of quantum tunneling in the catalytic process. DFT calculations have been used to unravel the reaction pathway and identify the rate-determining step. Aditionally, isotopic effects were considered by different methods, and tunneling effects have been calculated to be crucial in the process. |
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