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Fast and reversible insertion of carbon dioxide into zirconocene-alkoxide bonds. A mechanistic study

Brink, Alice; Truedsson, Ida LU ; Fleckhaus, André LU ; Johnson, Magnus LU ; Norrby, Per Ola; Roodt, Andreas and Wendt, Ola LU (2014) In Dalton Transactions 43(23). p.8894-8898
Abstract
In two consecutive equilibria the compound (Cp*)(2)Zr(OMe)(2) undergoes insertion of CO2 to form the mono- and bis-hemicarbonates. Both equilibria are exothermic but entropically disfavoured. Magnetisation transfer experiments gave kinetic data for the first equilibrium showing that the rate of insertion is overall second order with a rate constant of 3.20 +/- 0.12 M-1 s(-1), which is substantially higher than those reported for other early transition metal alkoxides, which are currently the best homogeneous catalysts for dimethyl carbonate formation from methanol and CO2. Activation parameters for the insertion reaction point to a highly ordered transition state and we interpret that as there being a substantial interaction between the... (More)
In two consecutive equilibria the compound (Cp*)(2)Zr(OMe)(2) undergoes insertion of CO2 to form the mono- and bis-hemicarbonates. Both equilibria are exothermic but entropically disfavoured. Magnetisation transfer experiments gave kinetic data for the first equilibrium showing that the rate of insertion is overall second order with a rate constant of 3.20 +/- 0.12 M-1 s(-1), which is substantially higher than those reported for other early transition metal alkoxides, which are currently the best homogeneous catalysts for dimethyl carbonate formation from methanol and CO2. Activation parameters for the insertion reaction point to a highly ordered transition state and we interpret that as there being a substantial interaction between the CO2 and the metal during the C-O bond formation. This is supported by DFT calculations showing the lateral attack by CO2 to have the lowest energy transition state. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Dalton Transactions
volume
43
issue
23
pages
8894 - 8898
publisher
Royal Society of Chemistry
external identifiers
  • wos:000336800700035
  • scopus:84901280849
ISSN
1477-9234
DOI
10.1039/c3dt53566e
language
English
LU publication?
yes
id
379cab00-37f4-4d9a-aa13-44c62d77a37b (old id 4552300)
date added to LUP
2014-07-17 09:58:44
date last changed
2017-01-01 03:18:27
@article{379cab00-37f4-4d9a-aa13-44c62d77a37b,
  abstract     = {In two consecutive equilibria the compound (Cp*)(2)Zr(OMe)(2) undergoes insertion of CO2 to form the mono- and bis-hemicarbonates. Both equilibria are exothermic but entropically disfavoured. Magnetisation transfer experiments gave kinetic data for the first equilibrium showing that the rate of insertion is overall second order with a rate constant of 3.20 +/- 0.12 M-1 s(-1), which is substantially higher than those reported for other early transition metal alkoxides, which are currently the best homogeneous catalysts for dimethyl carbonate formation from methanol and CO2. Activation parameters for the insertion reaction point to a highly ordered transition state and we interpret that as there being a substantial interaction between the CO2 and the metal during the C-O bond formation. This is supported by DFT calculations showing the lateral attack by CO2 to have the lowest energy transition state.},
  author       = {Brink, Alice and Truedsson, Ida and Fleckhaus, André and Johnson, Magnus and Norrby, Per Ola and Roodt, Andreas and Wendt, Ola},
  issn         = {1477-9234},
  language     = {eng},
  number       = {23},
  pages        = {8894--8898},
  publisher    = {Royal Society of Chemistry},
  series       = {Dalton Transactions},
  title        = {Fast and reversible insertion of carbon dioxide into zirconocene-alkoxide bonds. A mechanistic study},
  url          = {http://dx.doi.org/10.1039/c3dt53566e},
  volume       = {43},
  year         = {2014},
}