Linked Life Data

18180040

Source:http://linkedlifedata.com/resource/pubmed/id/18180040

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2008-2-25
pubmed:abstractText
A combination of magnetic circular dichroism (MCD), electronic absorption spectroscopy and time-dependent density functional theory (TD-DFT) calculations has been used to investigate the electronic structure of azulene-fused pi-expanded porphyrins based primarily on the spectral properties of absorption bands in the near infrared region. From MCD experiments, it was suggested that in the case of a mono-azulene-fused porphyrin DeltaHOMO approximately equal DeltaLUMO (where DeltaHOMO is the magnitude of the energy gap between the HOMO and HOMO-1 and DeltaLUMO is the magnitude of the energy gap between the LUMO and LUMO+1), while in the case of an oppositely-di-azulene-fused porphyrin, DeltaHOMO<DeltaLUMO. Since Faraday A terms are observed for both the Soret and Q bands in the MCD spectrum of tetra-azulene-fused porphyrin the corresponding excited states are clearly accidentally degenerate despite the C(2) molecular symmetry. Transition dipole moment analysis clearly demonstrates that the electronic absorption spectrum of tetra-azulene-fused porphyrin has out-of-plane electronic transitions slightly to the blue of the main Q and Soret bands. Comparison with distorted porphyrins and phthalocyanines strongly suggests that these out-of-plane transitions appear as intense Gaussian-shaped Faraday B terms in the MCD spectra.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0162-0134
pubmed:author
pubmed:issnType
Print
pubmed:volume
102
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
466-71
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Electronic structures of azulene-fused porphyrins as seen by magnetic circular dichroism and TD-DFT calculations.
pubmed:affiliation
Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't