Linked Life Data

15731872

Source:http://linkedlifedata.com/resource/pubmed/id/15731872

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2005-2-25
pubmed:abstractText
Tris-porphyrin and tetrakis-porphyrin arrays 1 and 2 are proposed as models for the arrangement of the chromophores that constitute photosynthetic reaction centres (PRC's). Their porphyrinic chromophores are similar in distance apart to the key chromophores of PRC's and the C2 symmetric arrangement of the macrocycles that constitute the 'special pair' where charge separation occurs is also incorporated. The use of zinc(II) and gold(III) chelation establishes an energy gradient for photoinduced electron transfer across each compound. Synthesis was achieved in good yields through a strategy that used the construction of biquinoxalinyl and Tröger's base linkages between the porphyrinoid components. Compounds which are bis-porphyrin molecular components of the arrays were also synthesised. Photophysical analyses indicate that long-range photoinduced energy and electron transfer processes occur in the extended arrays in addition to those occurring in the component bis-porphyrins. Evidence for step-wise electron transfer between terminal zinc(II)-chelated and gold(III)-chelated porphyrins has been detected in both porphyrins 1 and 2 in polar solvents, representing charge transfer across 35 A and 50 A, respectively. At 298 K, in deaerated benzonitrile, the lifetime of the charge transfer state of the tris-porphyrin 1 is 150 ns and the lifetime of the charge transfer state of tetrakis-porphyrin 2 is 59.4 micros; very long when compared to simpler chemical model systems, but still much shorter than the 1 s lifetime of the charge separated state of natural PRC's in cell membranes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1477-0520
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
3
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
852-65
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Chemical models for aspects of the photosynthetic reaction centre: synthesis and photophysical properties of tris- and tetrakis-porphyrins that resemble the arrangement of chromophores in the natural system.
pubmed:affiliation
School of Chemistry, University of Sydney, NSW 2006, Australia. m.crossley@chem.usyd.edu.au
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't