Linked Life Data

20565079

Source:http://linkedlifedata.com/resource/pubmed/id/20565079

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
28
pubmed:dateCreated
2010-7-29
pubmed:abstractText
We describe the synthesis, characterization, aqueous behavior, and catalytic activity of a new generation of Fe(III)-TAML (tetraamido macrocycle ligand) activators of peroxides (2), variants of [Fe{(OC)(2)(o,o'-NC(6)H(4)NCO)(2)CMe(2)}(OH(2))(-)] (2d), which have been designed to be especially suitable for purifying water of recalcitrant oxidizable pollutants. Activation of H(2)O(2) by 2 (k(I)) as a function of pH was analyzed via kinetic studies of Orange II bleaching. This was compared with the known behavior of the first generation of Fe(III)-TAMLs (1). Novel reactivity features impact the potential for oxidant activation for water purification by 2d and its aromatic ring-substituted dinitro (2e) and tetrachloro (2f) derivatives. Thus, the maximum activity for 2e occurs at pH 9, the closest yet to the EPA guidelines for drinking water (6.5-8.5), allowing 2e to rapidly activate H(2)O(2) at pH 7.7. In water, 2e has two axial water ligands with pK(a)'s of 8.4 and 10.0 (25 degrees C). The former is the lowest for all Fe(III)-TAMLs developed to date and is key to 2e's exceptional catalytic activity in neutral and slightly basic solutions. Below pH 7, 2d was found to be quite sensitive to demetalation in phosphate buffers. This was overcome by iterative design to give 2e (hydrolysis rate 2d > 100 x 2e). Mechanistic studies highlight 2e's increased stability by establishing that to demetalate 2e at a comparable rate to which H(2)PO(4)(-) demetalates 2d, H(3)PO(4) is required. A critical criterion for green catalysts for water purification is the avoidance of endocrine disruptors, which can impair aquatic life. Fe(III)-TAMLs do not alter transcription mediated by mammalian thyroid, androgen, or estrogen hormone receptors, suggesting that 2 do not bind to the receptors and reducing concerns that the catalysts might have endocrine disrupting activity.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/20565079-11951040, http://linkedlifedata.com/resource/pubmed/commentcorrection/20565079-12198127, http://linkedlifedata.com/resource/pubmed/commentcorrection/20565079-13058869, http://linkedlifedata.com/resource/pubmed/commentcorrection/20565079-14531659, http://linkedlifedata.com/resource/pubmed/commentcorrection/20565079-16967942, http://linkedlifedata.com/resource/pubmed/commentcorrection/20565079-17909648, http://linkedlifedata.com/resource/pubmed/commentcorrection/20565079-18335938, http://linkedlifedata.com/resource/pubmed/commentcorrection/20565079-18351108, http://linkedlifedata.com/resource/pubmed/commentcorrection/20565079-18351731, http://linkedlifedata.com/resource/pubmed/commentcorrection/20565079-18722448, http://linkedlifedata.com/resource/pubmed/commentcorrection/20565079-18928252, http://linkedlifedata.com/resource/pubmed/commentcorrection/20565079-19502515, http://linkedlifedata.com/resource/pubmed/commentcorrection/20565079-19928965, http://linkedlifedata.com/resource/pubmed/commentcorrection/20565079-9784494
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1520-5126
pubmed:author
pubmed:issnType
Electronic
pubmed:day
21
pubmed:volume
132
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9774-81
pubmed:dateRevised
2011-8-1
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Designing green oxidation catalysts for purifying environmental waters.
pubmed:affiliation
Department of Chemistry, Institute of Green Science, Mellon Institute, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural