Linked Life Data

19864626

Source:http://linkedlifedata.com/resource/pubmed/id/19864626

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
45
pubmed:dateCreated
2009-11-11
pubmed:abstractText
Driven by the depletion of crude oil, the direct oxidation of methane to methanol has been of considerable interest. Promising low-temperature activity of an oxygen-activated zeolite, Cu-ZSM-5, has recently been reported in this selective oxidation and the active site in this reaction correlates with an absorption feature at 22,700 cm(-1). In the present study, this absorption band is used to selectively resonance enhance Raman vibrations of this active site. (18)O(2) labeling experiments allow definitive assignment of the observed vibrations and exclude all previously characterized copper-oxygen species for the active site. In combination with DFT and normal coordinate analysis calculations, the oxygen activated Cu core is uniquely defined as a bent mono-(mu-oxo)dicupric site. Spectroscopically validated electronic structure calculations show polarization of the low-lying singly-occupied molecular orbital of the [Cu(2)O](2+) core, which is directed into the zeolite channel, upon approach of CH(4). This induces significant oxyl character into the bridging O atom leading to a low transition state energy consistent with experiment and explains why the bent mono-(mu-oxo)dicupric core is highly activated for H atom abstraction from CH(4). The oxygen intermediate of Cu-ZSM-5 is now the most well defined species active in the methane monooxygenase reaction.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/19864626-12517160, http://linkedlifedata.com/resource/pubmed/commentcorrection/19864626-12812505, http://linkedlifedata.com/resource/pubmed/commentcorrection/19864626-15674245, http://linkedlifedata.com/resource/pubmed/commentcorrection/19864626-15686370, http://linkedlifedata.com/resource/pubmed/commentcorrection/19864626-15811799, http://linkedlifedata.com/resource/pubmed/commentcorrection/19864626-17212392, http://linkedlifedata.com/resource/pubmed/commentcorrection/19864626-17328677, http://linkedlifedata.com/resource/pubmed/commentcorrection/19864626-19093853, http://linkedlifedata.com/resource/pubmed/commentcorrection/19864626-19286415, http://linkedlifedata.com/resource/pubmed/commentcorrection/19864626-19889982, http://linkedlifedata.com/resource/pubmed/commentcorrection/19864626-8255292, http://linkedlifedata.com/resource/pubmed/commentcorrection/19864626-864114
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1091-6490
pubmed:author
pubmed:issnType
Electronic
pubmed:day
10
pubmed:volume
106
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
18908-13
pubmed:dateRevised
2010-9-28
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
A [Cu2O]2+ core in Cu-ZSM-5, the active site in the oxidation of methane to methanol.
pubmed:affiliation
Department of Chemistry, Stanford University, Stanford, CA 94305, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural