Linked Life Data

205241

Source:http://linkedlifedata.com/resource/pubmed/id/205241

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1978-6-28
pubmed:abstractText
The electronic structures of the cation and anion of bacteriopheophytin alpha monomer are investigated by the self-consistent charge extended Hückel procedure including both pi and sigma electrons in the molecule. The calculated electron distributions are tested by comparison of the predicted hyperfine fields at proton sites with experimental data in both the ions and most important, by their ability to explain the observed trend in the hyperfine fields in going from the cation bacteriopheophytin+ alpha to the anion, a trend that is similar in many respects to the corresponding observed trend for the bacteriochlorophyll alpha cation and anion. Good agreement is obtained with experiment both for the absolute values of the observed proton hyperfine fields in both bacteriopheophytin a cation and anion as well as the ratio of the corresponding fields for the two systems. In particular, our calculated electron distributions in the two molecules lead, for the cation, to substantially different proton hyperfine fields for the two methyl groups attached to rings I and III, while for the anion, the corresponding fields are much closer to each other, a trend in good agreement with recent data. Also explained are the features of larger methine hyperfine constants in the anion as compared to the cation and the reverse trend for the protons in rings II and IV. Other features of the calculated electron distributions in the cation and anion are discussed and compared with each other. Possible additional measurements in the two systems that could provide further tests of the theoretically obtained electron distribution will be pointed out.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
11
pubmed:volume
502
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
61-79
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1978
pubmed:articleTitle
Theory of proton hyperfine interactions in bacterial photosynthetic systems. Bacteriopheophytin cation and anion.
pubmed:publicationType
Journal Article