Linked Life Data

12693211

Source:http://linkedlifedata.com/resource/pubmed/id/12693211

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2003-4-15
pubmed:abstractText
[Co(2,9-dimethyl-1,10-phenanthroline)(solvent)4]2+ ([Co(neo)]2+) undergoes a significant decrease in symmetry to form an inner-sphere surface complex when grafted directly on performed silica or introduced during the sol-gel process. The visible and X-ray absorption spectra of the surface adducts are interpreted in terms of a binding mode in which the Co(II) center has a highly distorted pseudo-C2v symmetry. The interaction of [Co(neo)]2+ with the silica surface was analyzed using an acid-base equilibrium relationship. Half-maximal surface binding was observed at pH ca. 6. Linear fits to the pH dependence data are consistent with inner-sphere binding of a single silanol group to the cobalt center. The formation of the surface species in tetramethoxyorthosilicate (TMOS) sol-gels required approximately 2 equiv of hydroxide anion per cobalt center, suggesting a two-proton-dependent binding event to form a species such as [Co(neo)(SiO)2]. Both sol-gel and silica samples showed essentially identical visible and X-ray absorption spectra, indicating formation of very similar surface adducts when the different synthesis procedures were employed. The maximal binding of [Co(neo)]2+ on three silica samples with different pore diameters and surface areas was compared. Increased binding was found to be inversely proportional to surface area and proportional to pore diameter, indicating a preference for less sterically demanding surface sites.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0020-1669
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
42
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
312-20
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Inner-sphere complexation of cobalt(II) 2,9-dimethyl-1,10-phenanthroline ([Co(neo)]2+) with commercial and sol-gel derived silica gel surfaces.
pubmed:affiliation
Department of Chemistry, Virginia Commonwealth University, 1001 West Main Street, Richmond, Virginia 23284, 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