TY - JOUR
T1 - Kinetics of ultra-fast excited state proton transfer from 7-hydroxy-4-methylflavylium chloride to water
AU - Lima, J. C.
AU - Abreu, Isabel
AU - Brouillard, Raymond
AU - Maçanita, António L.
PY - 1998/12/11
Y1 - 1998/12/11
N2 - Excited state proton transfer from 7-hydroxy-4-methylflavylium chloride to water is reported. From a modified analysis of picosecond time-resolved fluorescence data (not using the lifetime of a parent compound), all rate constants were determined: the deprotonation rate constant of the flavylium cation, kd=1.4×1011 s-1, the protonation rate constant of the base form, kp=2.3×1010 l mol-1 s-1 and the reciprocal fluorescence lifetimes of these species, kAH
+=7.8×109 s-1 (τAH
+=128 ps) and kA=7.6×109 s-1 (τA=132 ps), in water, at 20°C. The value of kd is the largest measured value for an intermolecular proton transfer (to water).
AB - Excited state proton transfer from 7-hydroxy-4-methylflavylium chloride to water is reported. From a modified analysis of picosecond time-resolved fluorescence data (not using the lifetime of a parent compound), all rate constants were determined: the deprotonation rate constant of the flavylium cation, kd=1.4×1011 s-1, the protonation rate constant of the base form, kp=2.3×1010 l mol-1 s-1 and the reciprocal fluorescence lifetimes of these species, kAH
+=7.8×109 s-1 (τAH
+=128 ps) and kA=7.6×109 s-1 (τA=132 ps), in water, at 20°C. The value of kd is the largest measured value for an intermolecular proton transfer (to water).
KW - Anthocyanins
KW - Flowers
KW - Flavylium cation
UR - http://www.scopus.com/inward/record.url?scp=0000458861&partnerID=8YFLogxK
U2 - 10.1016/S0009-2614(98)01199-3
DO - 10.1016/S0009-2614(98)01199-3
M3 - Article
AN - SCOPUS:0000458861
SN - 0009-2614
VL - 298
SP - 189
EP - 195
JO - Chemical Physics Letters
JF - Chemical Physics Letters
IS - 1-3
ER -