Abstract
The addition of water to nine silenes (H2Si=CH2 (1), Me2Si=C(SiH3)2 (2), Cl2Si=CH2 (3), Me2Si=CMe2 (4), (H3Si)2Si=CMe2 (5), (H3Si)2Si=C(Me)OSiH3 (6), Me2Si=C(SiMe3)H (7), Me(HCC)Si=CH2 (8), and Me(Me3Si)Si=CH2 (9)) was studied with ab initio (MP4/6-31+G(d,p)) and DFT (B3LYP/6-31G(d)) methods. The energy barriers for addition, which denote the kinetic stability of the silene, strongly depend on the substituents. Silenes (1-4) exhibit low and even negative activation energies (-3 to 8 kcal/mol). Substituents that strongly reduce the polarity of the silene, as in 5 and 6, increase significantly the activation energy for the nucleophilic addition of H2O to ca. 16 kcal/mol. The calculated activation energies show a good correlation with Δt (Δt = the difference in the total NBO charge between Si and C), i.e., the higher the polarity of the silene the lower is the activation barrier for water addition.
| Original language | English |
|---|---|
| Pages (from-to) | 3930-3939 |
| Number of pages | 10 |
| Journal | Organometallics |
| Volume | 21 |
| Issue number | 19 |
| DOIs | |
| Publication status | Published - Sep 16 2002 |
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ASJC Scopus subject areas
- Inorganic Chemistry
- Organic Chemistry
Cite this
Addition of nucleophiles to silenes. A theoretical study of the effect of substituents on their kinetic stability. / Bendikov, Michael; Quadt, Sabine Ruth; Rabin, Oded; Apeloig, Yitzhak.
In: Organometallics, Vol. 21, No. 19, 16.09.2002, p. 3930-3939.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Addition of nucleophiles to silenes. A theoretical study of the effect of substituents on their kinetic stability
AU - Bendikov, Michael
AU - Quadt, Sabine Ruth
AU - Rabin, Oded
AU - Apeloig, Yitzhak
PY - 2002/9/16
Y1 - 2002/9/16
N2 - The addition of water to nine silenes (H2Si=CH2 (1), Me2Si=C(SiH3)2 (2), Cl2Si=CH2 (3), Me2Si=CMe2 (4), (H3Si)2Si=CMe2 (5), (H3Si)2Si=C(Me)OSiH3 (6), Me2Si=C(SiMe3)H (7), Me(HCC)Si=CH2 (8), and Me(Me3Si)Si=CH2 (9)) was studied with ab initio (MP4/6-31+G(d,p)) and DFT (B3LYP/6-31G(d)) methods. The energy barriers for addition, which denote the kinetic stability of the silene, strongly depend on the substituents. Silenes (1-4) exhibit low and even negative activation energies (-3 to 8 kcal/mol). Substituents that strongly reduce the polarity of the silene, as in 5 and 6, increase significantly the activation energy for the nucleophilic addition of H2O to ca. 16 kcal/mol. The calculated activation energies show a good correlation with Δt (Δt = the difference in the total NBO charge between Si and C), i.e., the higher the polarity of the silene the lower is the activation barrier for water addition.
AB - The addition of water to nine silenes (H2Si=CH2 (1), Me2Si=C(SiH3)2 (2), Cl2Si=CH2 (3), Me2Si=CMe2 (4), (H3Si)2Si=CMe2 (5), (H3Si)2Si=C(Me)OSiH3 (6), Me2Si=C(SiMe3)H (7), Me(HCC)Si=CH2 (8), and Me(Me3Si)Si=CH2 (9)) was studied with ab initio (MP4/6-31+G(d,p)) and DFT (B3LYP/6-31G(d)) methods. The energy barriers for addition, which denote the kinetic stability of the silene, strongly depend on the substituents. Silenes (1-4) exhibit low and even negative activation energies (-3 to 8 kcal/mol). Substituents that strongly reduce the polarity of the silene, as in 5 and 6, increase significantly the activation energy for the nucleophilic addition of H2O to ca. 16 kcal/mol. The calculated activation energies show a good correlation with Δt (Δt = the difference in the total NBO charge between Si and C), i.e., the higher the polarity of the silene the lower is the activation barrier for water addition.
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U2 - 10.1021/om0202571
DO - 10.1021/om0202571
M3 - Article
VL - 21
SP - 3930
EP - 3939
JO - Organometallics
JF - Organometallics
SN - 0276-7333
IS - 19
ER -