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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2006-7-12
pubmed:abstractText
Hydrogen bonds were shown to play an important role in the lumichrome photophysics and photochemistry both in solutions and in the solid state. In solutions, lumichrome can form hydrogen-bonded complexes with a variety of molecules, such as acetic acid or methanol, as supported by spectral and equilibrium studies. Photoexcitation of some hydrogen-bonded complexes, having appropriate configuration, as in the case of acetic acid, may lead to excited-state proton transfer, resulting in formation of the isoalloxazinic structure, detectable by its characteristic emission, distinct from that of the intrinsically alloxazinic lumichrome. Theoretical calculations confirmed the role of the hydrogen-bonded complexes, yielding several stable eight-membered cyclic structures of such complexes characterized by spectral changes similar to those observed experimentally. Hydrogen bonds play an essential role in the formation of the lumichrome crystal structure, as follows from the X-ray diffraction results. Interestingly, the crystals studied included molecules of methanol used as solvent in crystal growth. The emission studies of polycrystalline samples, similar to the processes occurring in solutions, point to the importance of hydrogen-bonding interactions in crystal packing allowed by the symmetry of the hydrogen-bonded dimers.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Mar
pubmed:issn
1089-5639
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
109
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1785-94
pubmed:year
2005
pubmed:articleTitle
Hydrogen-bonded complexes of lumichrome.
pubmed:affiliation
Faculty of Commodity Science, Pozna? University of Economics, al. Niepodleglo?ci 10, 60-967 Pozna?, Poland. ewa.sikorska@ae.poznan.pl
pubmed:publicationType
Journal Article