Linked Life Data

12401092

Source:http://linkedlifedata.com/resource/pubmed/id/12401092

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
22
pubmed:dateCreated
2002-10-28
pubmed:abstractText
Vitamin B(12) catalyzes the reductive dechlorination of perchloroethylene (PCE), a process for which vinylcobalamins have been proposed as intermediates. Previous model studies have shown that PCE and trichloroethlylene (TCE) react with cob(I)aloxime to form cis-1,2-dichlorovinylcobaloxime (1). This compound could be formed by nucleophilic vinylic substitution of cob(I)aloxime on TCE or its syn-addition to dichloroacetylene. To evaluate the latter possibility, dichloroacetylene was reacted in this study with cob(I)aloxime. The major product was not complex 1 but a novel cobalt complex, indicating that dichloroacetylene is not involved in the reductive dechorination of PCE catalyzed by cob(I)aloxime. An X-ray structure of the major product was obtained showing an unexpected tricyclic structure in which one of the carbons of dichloroacetylene is a ligand to the metal and the second carbon has formed a C-C bond to one of the oxime carbons. This arrangement connects the axial and equatorial ligands. The cathodic peak potential of this complex is significantly more negative than that of previously characterized chlorinated vinylcobaloximes. Cob(I)alamin also reacts with chloroacetylene to provide cis-chlorovinylcobalamin in analogy to cob(I)aloxime, but it does not provide dichlorinated vinylcobalamins in the reaction with dichloroacetylene. Hence, dichlorinated vinylcobalt complexes detected in the reductive dechlorination of PCE catalyzed by cobaloximes or vitamin B(12) are not derived from a dichloroacetylene intermediate.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0020-1669
pubmed:author
pubmed:issnType
Print
pubmed:day
4
pubmed:volume
41
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5844-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Dichloroacetylene is not the precursor to dichlorinated vinylcobaloxime and vinylcobalamin in cobalt catalyzed dechlorination of perchloro- and trichloroethylene.
pubmed:affiliation
Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL 61801, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't