this family of compounds. Besides those of natural origin such as anthocyanidins and deoxyanthocyanidins, anthocyanins have been a source of bio‐inspiration for the synthesis of new derivatives that permit us to achieve complexity at the bottom, through this multistate of chemical species. The multistate of chemical species can be operated by pH changes, light, temperature, and host‐guest chemistry. The light response is particularly challenging, since there are two photochromic systems: (i) the ring opening of the hemiketal to produce cis‐chalcone, and (ii) cis‐trans isomerization of the chalcones. The multistate response can be modulated by host‐guest chemistry, increasing the potentialities of the system as photochromic materials, or in the domain of the health sciences.
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Endnotes
1 1 In previous work we have used the term mono ionized, in the sense of formation of ions. This was the term used for ions resulting from the acid‐base reactions and the respective constants were defined as ionization constants.
2 2 In any case, both processes are well separated in time and the respective amplitude can be obtained.
3 3 In the case of 4’‐hydroxyflavylium
