Linked Life Data

20148589

Source:http://linkedlifedata.com/resource/pubmed/id/20148589

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2010-3-3
pubmed:abstractText
Protonation-triggered conformational changes of meso-octakis(pentafluorophenyl) [36]octaphyrin and [38]octaphyrin have been investigated. The X-ray crystal structures and (1)H NMR analyses revealed that the protonation process cuts off intramolecular hydrogen bonds between aminic and iminic pyrrole units and, at the same time, produces intermolecular hydrogen-bond network between aminic pyrrole unit and counter-anions. Such a replacement induces some pyrrole inversion, leading to Mobius aromatic conformation for [36]octaphyrin and to Huckel aromatic conformation for [38]octaphyrin. These protonated octaphyrins show similar structures only with a subtle difference in tilted pyrrole angles, which results in their different topologies. This feature strongly suggests that the macrocycles control their topologies by pyrrole rotation to gain [4n]pi Mobius or [4n+2]pi Huckel aromatic stabilization, depending on the number of pi-electrons. Detailed photophysical properties such as absorption/fluorescence, excited singlet/triplet state lifetimes, and two-photon absorption cross-section values have been presented for both protonated [36] and [38]octaphyrins in conjunction with their Mobius or Huckel aromaticity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1520-5126
pubmed:author
pubmed:issnType
Electronic
pubmed:day
10
pubmed:volume
132
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3105-14
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Protonated [4n]pi and [4n+2]pi octaphyrins choose their Möbius/Hückel aromatic topology.
pubmed:affiliation
Spectroscopy Laboratory for Functional pi-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 120-749, Korea.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't