Abstract
Oxidative addition of H-R (H - Ph and H2) to trans-Ir( - Ph)(CO)(PPh3)2 (2) gives the initial products, cis, cis-Ir(H)( - Ph)2(CO)(PPh3)2 (3a) and cis, cis-Ir(H)2( - Ph)(CO)(PPh3)2 (3b), respectively. Both cis-bis(PPh3) complexes, 3a and 3b undergo isomerization to give the trans-bis(PPh3) complexes, trans, trans-Ir(H)( - Ph)2(CO)(PPh3)2 (4a) and cis, trans-Ir(H)2( - Ph)(CO)(PPh3)2 (4b). The isomerization, 3b→4b is first order with respect to 3b with k1=6.37×10-4 s-1 at 25°C under N2 in CDCl3. The reaction rate (k1) seems independent of the concentration of H2. A large negative entropy of activation (ΔS≠=-24.9±5.7 cal deg-1 mol-1) and a relatively small enthalpy of activation (ΔH≠=14.5±3.3 kcal mol-1) were obtained in the temperature range 15~35°C for the isomerization, 3b→4b under 1 atm of H2.
| Original language | English |
|---|---|
| Pages (from-to) | 811-815 |
| Number of pages | 5 |
| Journal | Polyhedron |
| Volume | 18 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 1999 Jan 22 |
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All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry
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Formation and isomerization of cis, cis-Ir(H)2( - Ph)(CO)(PPh3)2 and cis, cis-Ir(H)( - Ph)2(CO)(PPh3)2 in oxidative addition of hydrogen and phenylacetylene to trans-Ir(CO)( - Ph)(PPh3)2. / Shik Chin, Chong; Oh, Moonhyun; Won, Gyongshik; Cho, Haeyeon; Shin, Dongchan.
In: Polyhedron, Vol. 18, No. 6, 22.01.1999, p. 811-815.Research output: Contribution to journal › Article
TY - JOUR
T1 - Formation and isomerization of cis, cis-Ir(H)2( - Ph)(CO)(PPh3)2 and cis, cis-Ir(H)( - Ph)2(CO)(PPh3)2 in oxidative addition of hydrogen and phenylacetylene to trans-Ir(CO)( - Ph)(PPh3)2
AU - Shik Chin, Chong
AU - Oh, Moonhyun
AU - Won, Gyongshik
AU - Cho, Haeyeon
AU - Shin, Dongchan
PY - 1999/1/22
Y1 - 1999/1/22
N2 - Oxidative addition of H-R (H - Ph and H2) to trans-Ir( - Ph)(CO)(PPh3)2 (2) gives the initial products, cis, cis-Ir(H)( - Ph)2(CO)(PPh3)2 (3a) and cis, cis-Ir(H)2( - Ph)(CO)(PPh3)2 (3b), respectively. Both cis-bis(PPh3) complexes, 3a and 3b undergo isomerization to give the trans-bis(PPh3) complexes, trans, trans-Ir(H)( - Ph)2(CO)(PPh3)2 (4a) and cis, trans-Ir(H)2( - Ph)(CO)(PPh3)2 (4b). The isomerization, 3b→4b is first order with respect to 3b with k1=6.37×10-4 s-1 at 25°C under N2 in CDCl3. The reaction rate (k1) seems independent of the concentration of H2. A large negative entropy of activation (ΔS≠=-24.9±5.7 cal deg-1 mol-1) and a relatively small enthalpy of activation (ΔH≠=14.5±3.3 kcal mol-1) were obtained in the temperature range 15~35°C for the isomerization, 3b→4b under 1 atm of H2.
AB - Oxidative addition of H-R (H - Ph and H2) to trans-Ir( - Ph)(CO)(PPh3)2 (2) gives the initial products, cis, cis-Ir(H)( - Ph)2(CO)(PPh3)2 (3a) and cis, cis-Ir(H)2( - Ph)(CO)(PPh3)2 (3b), respectively. Both cis-bis(PPh3) complexes, 3a and 3b undergo isomerization to give the trans-bis(PPh3) complexes, trans, trans-Ir(H)( - Ph)2(CO)(PPh3)2 (4a) and cis, trans-Ir(H)2( - Ph)(CO)(PPh3)2 (4b). The isomerization, 3b→4b is first order with respect to 3b with k1=6.37×10-4 s-1 at 25°C under N2 in CDCl3. The reaction rate (k1) seems independent of the concentration of H2. A large negative entropy of activation (ΔS≠=-24.9±5.7 cal deg-1 mol-1) and a relatively small enthalpy of activation (ΔH≠=14.5±3.3 kcal mol-1) were obtained in the temperature range 15~35°C for the isomerization, 3b→4b under 1 atm of H2.
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U2 - 10.1016/S0277-5387(98)00358-1
DO - 10.1016/S0277-5387(98)00358-1
M3 - Article
AN - SCOPUS:0040036700
VL - 18
SP - 811
EP - 815
JO - Polyhedron
JF - Polyhedron
SN - 0277-5387
IS - 6
ER -