TY - JOUR
T1 - Ion-pairing co-pigmentation with 4′,7-dihydroxyflavylium studied by pulse light jumps
AU - Pina, Fernando
AU - Roque, Ana
PY - 1998/3/31
Y1 - 1998/3/31
N2 - Pulse light and pH jumps were used to study the structural transformations of the 4′,7-dihydroxyflavylium cation when involved in ion-pairs with the anions chloride, bromide and perchlorate. The association constants of the ion-pairs were calculated by a new approach based on two spectrophotometric titrations; (i) in the absence and. (ii) in the presence of a constant concentration of co-pigment. This method was also used to calculate the ion-pairing association constants of Malvin and the same anions. On the basis of our results, the co-pigmentation model based on the suppression of the hydration reaction in the flavylium complex is questioned.
AB - Pulse light and pH jumps were used to study the structural transformations of the 4′,7-dihydroxyflavylium cation when involved in ion-pairs with the anions chloride, bromide and perchlorate. The association constants of the ion-pairs were calculated by a new approach based on two spectrophotometric titrations; (i) in the absence and. (ii) in the presence of a constant concentration of co-pigment. This method was also used to calculate the ion-pairing association constants of Malvin and the same anions. On the basis of our results, the co-pigmentation model based on the suppression of the hydration reaction in the flavylium complex is questioned.
KW - 4′
KW - 7-dihydroxyflavylium
KW - Co-pigmentation
KW - Ion-pairing
UR - http://www.scopus.com/inward/record.url?scp=0032583963&partnerID=8YFLogxK
U2 - 10.1016/S1010-6030(97)00312-2
DO - 10.1016/S1010-6030(97)00312-2
M3 - Article
AN - SCOPUS:0032583963
SN - 1010-6030
VL - 114
SP - 59
EP - 64
JO - Journal of Photochemistry and Photobiology A: Chemistry
JF - Journal of Photochemistry and Photobiology A: Chemistry
IS - 1
ER -