Preferential cesium ion trapping by 2-pyrone-4,6-dicarboxylic acid (PDC) obtained from a metabolic intermediate of lignin, a woody biomass resource

2-Pyrone-4,6-dicarboxylic acid (PDC), a chemically stable metabolic intermediate of lignin, showed preferential Cs⁺ sedimentation even from the aqueous solutions containing other alkali metal ions, such as Na⁺. From the crystal structure of the Cs⁺/PDC complex, Cs⁺ was revealed to be coordinated by 10 oxygen atoms of PDC and such multiple coordination was the reason of the preferential complex formation of Cs⁺ with PDC.