TY - JOUR
T1 - Radical species derived from phenalenone
T2 - Characterization and role of upper excited states
AU - Flors, Cristina
AU - Nonell, Santi
N1 - Funding Information:
This work has been supported by the Spanish Ministry of Science and Technology (SAF2002-04034-C02-02) and the European Union (FEDER). C.F. thanks the Departament d’Universitats, Recerca i Societat de la Informació of the Catalonian Government (DURSI) for a predoctoral fellowship.
PY - 2004/4/15
Y1 - 2004/4/15
N2 - The reactivity of triplet phenalenone (PN) towards typical H- and electron-donors is characterized by means of nanosecond laser flash-photolysis. H-abstraction from tributylstannane occurs with a rate constant of ca. 5×105 M-1 s-1. From the activation energy for this reaction, an upper limit for the T2-T1 energy gap is calculated as 9±1 kJ mol-1 in nonpolar solvents, consistent with the solvent-insensitive high ΦT value in phenalenone. Triplet phenalenone also reacts via photoinduced electron transfer with 1,4-diazabicyclo[2.2.2]octane (DABCO) with rate constant close to the diffusional control limit. The spectrum of the solvated free radical anion of phenalenone has a maximum at 440 nm in acetonitrile.
AB - The reactivity of triplet phenalenone (PN) towards typical H- and electron-donors is characterized by means of nanosecond laser flash-photolysis. H-abstraction from tributylstannane occurs with a rate constant of ca. 5×105 M-1 s-1. From the activation energy for this reaction, an upper limit for the T2-T1 energy gap is calculated as 9±1 kJ mol-1 in nonpolar solvents, consistent with the solvent-insensitive high ΦT value in phenalenone. Triplet phenalenone also reacts via photoinduced electron transfer with 1,4-diazabicyclo[2.2.2]octane (DABCO) with rate constant close to the diffusional control limit. The spectrum of the solvated free radical anion of phenalenone has a maximum at 440 nm in acetonitrile.
KW - Aromatic ketone
KW - Hydrogen abstraction
KW - Ketyl radical
KW - Phenalenone
KW - Photoinduced electron transfer
KW - Radical anion
UR - http://www.scopus.com/inward/record.url?scp=1342264913&partnerID=8YFLogxK
U2 - 10.1016/j.jphotochem.2004.01.001
DO - 10.1016/j.jphotochem.2004.01.001
M3 - Article
AN - SCOPUS:1342264913
SN - 1010-6030
VL - 163
SP - 9
EP - 12
JO - Journal of Photochemistry and Photobiology A: Chemistry
JF - Journal of Photochemistry and Photobiology A: Chemistry
IS - 1-2
ER -