Abstract
The rate of reaction of hydrogen with the 17 e- metal centered radical ·Cr(CO)3C5Me5 obeys the third-order rate law d[P]/dt=kobs[·Cr]2[H2] in toluene solution. In the temperature range 20-60°C, kobs=330±30 M-2 s-1, ΔH≠=0±1 kcal mol-1, ΔS≠=-47±3 cal mol-1 deg-1. The rate of oxidative addition is not inhibited by added pressure of CO. The rate of binding of D2 is slower than that of H2: k(H2)/k(D2)=1.18. These results are combined with earlier work to generate a complete reaction profile for hydrogenation of the metal-metal bonded dimer [Cr(CO)3C5Me5]2+H 2→2H-Cr(CO)3C5Me5. A similar reaction profile for Co2(CO)8+H2→2H-Co(CO)4 under high pressures of CO is constructed based on literature data and estimated activation parameters for reaction of the ·Co(CO)4 radical with hydrogen.
| Original language | English |
|---|---|
| Pages (from-to) | 23-30 |
| Number of pages | 8 |
| Journal | Journal of Organometallic Chemistry |
| Volume | 586 |
| Issue number | 1 |
| State | Published - Jul 31 1999 |
Fingerprint
Keywords
- Chromium
- Cobalt
- Free radicals
- Hydrogen
- Oxidative addition
ASJC Scopus subject areas
- Biochemistry
- Inorganic Chemistry
- Organic Chemistry
- Physical and Theoretical Chemistry
- Materials Chemistry
Cite this
The rate and mechanism of oxidative addition of H2 to the ·Cr(CO)3C5Me5 radical - Generation of a model for reaction of H2 with the ·Co(CO)4 radical. / Capps, Kenneth B.; Bauer, Andreas; Kiss, Gabor; Hoff, Carl.
In: Journal of Organometallic Chemistry, Vol. 586, No. 1, 31.07.1999, p. 23-30.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The rate and mechanism of oxidative addition of H2 to the ·Cr(CO)3C5Me5 radical - Generation of a model for reaction of H2 with the ·Co(CO)4 radical
AU - Capps, Kenneth B.
AU - Bauer, Andreas
AU - Kiss, Gabor
AU - Hoff, Carl
PY - 1999/7/31
Y1 - 1999/7/31
N2 - The rate of reaction of hydrogen with the 17 e- metal centered radical ·Cr(CO)3C5Me5 obeys the third-order rate law d[P]/dt=kobs[·Cr]2[H2] in toluene solution. In the temperature range 20-60°C, kobs=330±30 M-2 s-1, ΔH≠=0±1 kcal mol-1, ΔS≠=-47±3 cal mol-1 deg-1. The rate of oxidative addition is not inhibited by added pressure of CO. The rate of binding of D2 is slower than that of H2: k(H2)/k(D2)=1.18. These results are combined with earlier work to generate a complete reaction profile for hydrogenation of the metal-metal bonded dimer [Cr(CO)3C5Me5]2+H 2→2H-Cr(CO)3C5Me5. A similar reaction profile for Co2(CO)8+H2→2H-Co(CO)4 under high pressures of CO is constructed based on literature data and estimated activation parameters for reaction of the ·Co(CO)4 radical with hydrogen.
AB - The rate of reaction of hydrogen with the 17 e- metal centered radical ·Cr(CO)3C5Me5 obeys the third-order rate law d[P]/dt=kobs[·Cr]2[H2] in toluene solution. In the temperature range 20-60°C, kobs=330±30 M-2 s-1, ΔH≠=0±1 kcal mol-1, ΔS≠=-47±3 cal mol-1 deg-1. The rate of oxidative addition is not inhibited by added pressure of CO. The rate of binding of D2 is slower than that of H2: k(H2)/k(D2)=1.18. These results are combined with earlier work to generate a complete reaction profile for hydrogenation of the metal-metal bonded dimer [Cr(CO)3C5Me5]2+H 2→2H-Cr(CO)3C5Me5. A similar reaction profile for Co2(CO)8+H2→2H-Co(CO)4 under high pressures of CO is constructed based on literature data and estimated activation parameters for reaction of the ·Co(CO)4 radical with hydrogen.
KW - Chromium
KW - Cobalt
KW - Free radicals
KW - Hydrogen
KW - Oxidative addition
UR - http://www.scopus.com/inward/record.url?scp=0001940147&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0001940147&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0001940147
VL - 586
SP - 23
EP - 30
JO - Journal of Organometallic Chemistry
JF - Journal of Organometallic Chemistry
SN - 0022-328X
IS - 1
ER -