Abstract
A theoretical study of the oxidative addition of C - C vs C - H bonds to a rhodium(I) complex with PCP-type ligands has been carried out. Special attention has been paid to the effect of different bulky substituents at the phosphorus atoms of the chelate ligand. Therefore, B3LYP/lanl2dz+p//B3LYP/lanl2dz and ONIOM(B3LYP/lanl2dz+p:B3LYP/lanl2dz)//ONIOM(B3LYP/lanl2dz:HF/lanl 1mb) methods have been utilized. According to the calculations, C - H activation is always the kinetically favored process (ΔΔE(≠) 20 kJ·mol-1), though the C - C activation product is more stable (ΔΔE 20 kJ·mol-1). C - H addition is a reversible process; the product of the C - H activation can interconvert to the C - C activation product via an intermediate structure. Bulky substituents are found to increase the barrier for C-H activation relative to that for C - C activation. With additional ligands (e.g., phosphines), hexacoordinate complexes are formed. This is more favorable for the C - C activation products. Our calculations show that the activation reaction proceeds via complexes with a pentacoordinated rhodium atom. Thus, in the presence of donor ligands, the activation reaction is inhibited.
| Original language | English |
|---|---|
| Pages (from-to) | 7095-7104 |
| Number of pages | 10 |
| Journal | Journal of the American Chemical Society |
| Volume | 122 |
| Issue number | 29 |
| DOIs | |
| Publication status | Published - Jul 26 2000 |
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ASJC Scopus subject areas
- Chemistry(all)
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Selective C - C vs C - H bond activation by rhodium(I) PCP pincer complexes. A computational study. / Sundermann, Andreas; Uzan, Olivier; Milstein, David; Martin, Jan M L.
In: Journal of the American Chemical Society, Vol. 122, No. 29, 26.07.2000, p. 7095-7104.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Selective C - C vs C - H bond activation by rhodium(I) PCP pincer complexes. A computational study
AU - Sundermann, Andreas
AU - Uzan, Olivier
AU - Milstein, David
AU - Martin, Jan M L
PY - 2000/7/26
Y1 - 2000/7/26
N2 - A theoretical study of the oxidative addition of C - C vs C - H bonds to a rhodium(I) complex with PCP-type ligands has been carried out. Special attention has been paid to the effect of different bulky substituents at the phosphorus atoms of the chelate ligand. Therefore, B3LYP/lanl2dz+p//B3LYP/lanl2dz and ONIOM(B3LYP/lanl2dz+p:B3LYP/lanl2dz)//ONIOM(B3LYP/lanl2dz:HF/lanl 1mb) methods have been utilized. According to the calculations, C - H activation is always the kinetically favored process (ΔΔE(≠) 20 kJ·mol-1), though the C - C activation product is more stable (ΔΔE 20 kJ·mol-1). C - H addition is a reversible process; the product of the C - H activation can interconvert to the C - C activation product via an intermediate structure. Bulky substituents are found to increase the barrier for C-H activation relative to that for C - C activation. With additional ligands (e.g., phosphines), hexacoordinate complexes are formed. This is more favorable for the C - C activation products. Our calculations show that the activation reaction proceeds via complexes with a pentacoordinated rhodium atom. Thus, in the presence of donor ligands, the activation reaction is inhibited.
AB - A theoretical study of the oxidative addition of C - C vs C - H bonds to a rhodium(I) complex with PCP-type ligands has been carried out. Special attention has been paid to the effect of different bulky substituents at the phosphorus atoms of the chelate ligand. Therefore, B3LYP/lanl2dz+p//B3LYP/lanl2dz and ONIOM(B3LYP/lanl2dz+p:B3LYP/lanl2dz)//ONIOM(B3LYP/lanl2dz:HF/lanl 1mb) methods have been utilized. According to the calculations, C - H activation is always the kinetically favored process (ΔΔE(≠) 20 kJ·mol-1), though the C - C activation product is more stable (ΔΔE 20 kJ·mol-1). C - H addition is a reversible process; the product of the C - H activation can interconvert to the C - C activation product via an intermediate structure. Bulky substituents are found to increase the barrier for C-H activation relative to that for C - C activation. With additional ligands (e.g., phosphines), hexacoordinate complexes are formed. This is more favorable for the C - C activation products. Our calculations show that the activation reaction proceeds via complexes with a pentacoordinated rhodium atom. Thus, in the presence of donor ligands, the activation reaction is inhibited.
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U2 - 10.1021/ja000943w
DO - 10.1021/ja000943w
M3 - Article
VL - 122
SP - 7095
EP - 7104
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 29
ER -