“…Some design intentions are listed as follows. (1) Water-soluble carboxylatopillar[5]arene possessed five carboxylate groups on each rim and good binding ability toward guest molecules [ 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ], which was selected as a supramolecular host. It may also have cation⋯π and electrostatic interactions with Hg 2+ .…”