Anthocyanin flavylium chromophore

Fig. 1.2 The anthocyanin flavylium chromophore, a carboxonium cation stable in aqueous media. R is usually sugar or acylated sugar.

Hydrophobic effects are thought to position the anthocyanin chromophore and the copigment to form a ti-ti complex [244], and by this way, the most efficient overlap would occur with planar flavonols when compared with hydroxyciimamoyl, galloyl esters, or with the nonplanar flavan-3-ols [245]. Usually, it is thought that the flavylium ion is the major colored species that contributes to the copigmentatirm phenomenon [244, 246]. However, some authors have suggested that the neutral quinoidal base is the main species involved [247, 248]. 

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