Kinetics and Mechanism of Metallacyclization in a Chloromethylcobalt Complex with a Salen-Type Ligand
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- 作者：Renata Dreos ; Patrizia Siega
- 刊名：Organometallics
- 出版年：2006
- 出版时间：October 9, 2006
- 年：2006
- 卷：25
- 期：21
- 页码：5180 - 5183
- 全文大小：64K
- 年卷期：v.25,no.21(October 9, 2006)
- ISSN：1520-6041
文摘
trans-[Co(CH2Cl)(tmsalen)(S)] undergoes metallacyclization in water/methanol, affording the cis 
organometallicderivative [Co(tmsalenCH2)(S)2]Cl. The presence of N-donorligands, L, increases the cyclization rate mainly by electroniceffects. The reaction involves the substitution of the solvent byL in a fast preequilibrium step, both [Co(CH2Cl)(tmsalen)(S)]and [Co(CH2Cl)(tmsalen)(L)] undergoing the cyclization reaction. As the cyclization involves the formation of ions from aneutral complex, the large negative activation entropy isattributed to the freezing of the solvent around the incipientions in the transition state.
organometallicderivative [Co(tmsalenCH2)(S)2]Cl. The presence of N-donorligands, L, increases the cyclization rate mainly by electroniceffects. The reaction involves the substitution of the solvent byL in a fast preequilibrium step, both [Co(CH2Cl)(tmsalen)(S)]and [Co(CH2Cl)(tmsalen)(L)] undergoing the cyclization reaction. As the cyclization involves the formation of ions from aneutral complex, the large negative activation entropy isattributed to the freezing of the solvent around the incipientions in the transition state.