TY - JOUR
T1 - Pressure effect on the excited-state proton transfer from curcumin to monols
AU - Presiado, Itay
AU - Erez, Yuval
AU - Gepshtein, Rinat
AU - Koifman, Naum
AU - Huppert, Dan
N1 - Funding Information:
This work was supported by grants from the James-Franck German-Israeli Program in Laser-Matter Interaction and by the Israel Science Foundation .
PY - 2012/11/1
Y1 - 2012/11/1
N2 - Time-resolved emission techniques were employed to study the pressure effect on curcumin's luminescence in several aliphatic alcohols. We found that the hydrostatic pressure of up to 2 GPa affects the decay rate of curcumin emission in the same way it affects the protonated form of many photoacids. We therefore propose that curcumin, which has two phenol groups, is a strong photoacid. Strong photoacids with pK a* < 0 can transfer a proton not only to water but also to alcohols, as curcumin does in these solvents.
AB - Time-resolved emission techniques were employed to study the pressure effect on curcumin's luminescence in several aliphatic alcohols. We found that the hydrostatic pressure of up to 2 GPa affects the decay rate of curcumin emission in the same way it affects the protonated form of many photoacids. We therefore propose that curcumin, which has two phenol groups, is a strong photoacid. Strong photoacids with pK a* < 0 can transfer a proton not only to water but also to alcohols, as curcumin does in these solvents.
KW - Excited-state proton transfer
KW - Nonradiative process
KW - Photoacid
KW - Pressure effect
KW - Time-resolved fluorescence
KW - Turmeric
UR - http://www.scopus.com/inward/record.url?scp=84865811408&partnerID=8YFLogxK
U2 - 10.1016/j.jphotochem.2012.08.007
DO - 10.1016/j.jphotochem.2012.08.007
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AN - SCOPUS:84865811408
SN - 1010-6030
VL - 247
SP - 42
EP - 51
JO - Journal of Photochemistry and Photobiology A: Chemistry
JF - Journal of Photochemistry and Photobiology A: Chemistry
ER -