TY - JOUR
T1 - β-Phenyl quenching of 9-phenylphenalenones
T2 - A novel photocyclisation reaction with biological implications
AU - Bucher, Götz
AU - Bresolí-Obach, Roger
AU - Brosa, Carme
AU - Flors, Cristina
AU - Luis, Javier G.
AU - Grillo, Teresa A.
AU - Nonell, Santi
PY - 2014/8/13
Y1 - 2014/8/13
N2 - The singlet and triplet excited states of 9-phenylphenalenones 1 undergo β-phenyl quenching (BPQ) via addition of the carbonyl oxygen to the ortho position of the phenyl substituent. This reaction leads to the formation of naphthoxanthenes 4, which, in the absence of quenchers, undergo a very rapid electrocyclic ring opening reaction reverting to 1 within a few microseconds. Naphthoxanthene 4a contains a remarkably weak C-H bond, which enables efficient hydrogen transfer reactions to suitable acceptors, giving rise to the production of the naphthoxanthenyl radical or the naphthoxanthenium cation, depending on the solvent polarity. The study uncovers a number of new aspects of BPQ and suggests an excited state-mediated metabolic pathway in the biosynthesis of plant fluorones.
AB - The singlet and triplet excited states of 9-phenylphenalenones 1 undergo β-phenyl quenching (BPQ) via addition of the carbonyl oxygen to the ortho position of the phenyl substituent. This reaction leads to the formation of naphthoxanthenes 4, which, in the absence of quenchers, undergo a very rapid electrocyclic ring opening reaction reverting to 1 within a few microseconds. Naphthoxanthene 4a contains a remarkably weak C-H bond, which enables efficient hydrogen transfer reactions to suitable acceptors, giving rise to the production of the naphthoxanthenyl radical or the naphthoxanthenium cation, depending on the solvent polarity. The study uncovers a number of new aspects of BPQ and suggests an excited state-mediated metabolic pathway in the biosynthesis of plant fluorones.
UR - http://www.scopus.com/inward/record.url?scp=84906214678&partnerID=8YFLogxK
U2 - 10.1039/c4cp02783c
DO - 10.1039/c4cp02783c
M3 - Article
C2 - 25079707
AN - SCOPUS:84906214678
SN - 1463-9076
VL - 16
SP - 18813
EP - 18820
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
IS - 35
ER -