For each cation receptor in Figure 10.19: (a) give a detailed overview of the molecular features that provide selectivity for a particular ion; (b) for each receptor in this figure, identify the...

For each cation receptor in Figure 10.19: (a) give a detailed overview of the molecular features that provide selectivity for a particular ion; (b) for each receptor in this figure, identify the molecule moiety that imparts lipophilicity; (c) why are long aliphatic chains included in the structure of the Ca2þ receptor in Figure 10.19C?