Abstract
Mild oxidants such as [Fe(C 5Me 5) 2] + accelerate the activation of H 2 by [Fe 2[(SCH 2) 2NBn](CO) 3(dppv)(PMe 3)] + ([1] +), despite the fact that the ferrocenium cation is incapable of oxidizing [1] +. The reaction is first-order in [1] + and [H 2] but independent of the E 1/2 and concentration of the oxidant. The analogous reaction occurs with D 2 and proceeds with an inverse kinetic isotope effect of 0.75(8). The activation of H 2 is further enhanced with the tetracarbonyl [Fe 2[(SCH 2) 2NBn](CO) 4(dppn)] + ([2] +), the first crystallographically characterized model for the H ox state of the active site containing an amine cofactor. These studies point to rate-determining binding of H 2 followed by proton-coupled electron transfer. Relative to that by [1] +, the rate of H 2 activation by [2] +/Fc + is enhanced by a factor of 10 4 at 25 °C.
Original language | English (US) |
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Pages (from-to) | 8098-8101 |
Number of pages | 4 |
Journal | Journal of the American Chemical Society |
Volume | 133 |
Issue number | 21 |
DOIs | |
State | Published - Jun 1 2011 |
ASJC Scopus subject areas
- Catalysis
- General Chemistry
- Biochemistry
- Colloid and Surface Chemistry