Linked Life Data

17147372

Source:http://linkedlifedata.com/resource/pubmed/id/17147372

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
49
pubmed:dateCreated
2006-12-6
pubmed:abstractText
The detailed reaction mechanism for the reduction of CO2 to CO catalyzed by (NHC)Cu(boryl) complexes (NHC = N-heterocyclic carbene) was studied with the aid of DFT by calculating the relevant intermediates and transition state structures. Our DFT calculations show that the reaction occurs through CO2 insertion into the Cu-B bond to give a Cu-OC(=O)-boryl species (i.e., containing Cu-O and C-B bonds), and subsequent boryl migration from C to O, followed by alpha-bond metathesis between pinB-Bpin (B2pin2, pin = pinacolate = OCMe2CMe2O) and (NHC)Cu(OBpin). The overall reaction is exergonic by 38.0 kcal/mol. It is the nucleophilicity of the Cu-B bond, a function of the very strong alpha-donor properties of the boryl ligand, rather than the oxophilicity of boron, which determines the direction of the CO2 insertion process. The boryl migration from C to O, which releases the product CO, is the rate-determining step and involves the "vacant" orbital orbital on boron. The (NHC)Cu(boryl) complexes show unique activity in the catalytic process. For the analogous (NHC)Cu(alkyl) complexes, the CO2 insertion into the Cu-C bond giving a copper acetate intermediate occurs with a readily achievable barrier. However, the elimination of CO from the acetate intermediate through a methyl migration from C to O is energetically inaccessible.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0002-7863
pubmed:author
pubmed:issnType
Print
pubmed:day
13
pubmed:volume
128
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
15637-43
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Density functional theory studies on the mechanism of the reduction of CO2 to CO catalyzed by copper(I) boryl complexes.
pubmed:affiliation
Department of Chemistry and Open Laboratory of Chirotechnology of the Institute of Molecular Technology for Drug Discovery and Synthesis, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't