Primary selectivity in the activation of the carbon-hydrogen bonds of propane by silica supported zirconium hydride Original Research Article

The stoichiometric reaction between propane and (≡ SiO)3ZrH leads to the formation of a mixture of (≡ SiO)3ZrCH(CH3)2 and (≡ SiO)3ZrCH2CH2CH3. The relative amounts of each complex resultant from the reaction was determined by (a) reaction of (≡ SiO)3ZrC3H7 with D2O to produce quantitatively a mixture of CH3CH3CH2D and CH3CHDCH3 which in turn were discriminated by mass spectroscopy, and (b) reaction of (≡ SiO)3ZrC3H7 with O2 followed by HCl yielding 1-propanol and 2-propanol in low yield. Each of these methods indicated that (≡ SiO)3ZrCH2CH2CH3 was the major product of propane activation. The catalytic deuteration of propane by deuterium at room temperature catalysed by (≡ SiO)3ZrH showed that the primary Csingle bondH bonds of propane reacted seven times faster than the secondary Csingle bondH bonds. A mechanism of degenerate carbon-hydrogen bond activation is invoked for the latter reaction.