The stability constants, log K of the 1 : 1 complexation for IA ions, $Ag^+$, and $Tl^+$ with a series of podands having different aromatic end-groups (I-IV) have been determined conductometrically in methanol at 25.0 $^{circ}$C. Exceptionally the equivalent conductivity, ${lambda}_{eq};of;Li^+;and;Na^+$ were increased by the addition of I, because the complexed ions are less mobile than solvated ions. The order of log K values for I was $Ag^+{gg}Tl^+>K^+>Na^+>Rb^+>Cs6+>Li^+$. The log K sequence of the podands for the certain cations was I>II>III${geq}$IV. And every podands except IV showed the maximum selectivity for $Ag^+$ among the cations. These results were discussed in terms of the aromatic end-group effects, such as hetero-donor atoms or conformational changes by ${pi}-{pi}$ stacking interactions. The detailed conformations of ${pi}-{pi}$ stacking were also discussed by the observations of upfield shifts of some aromatic protons upon complexation from $^1H$ NMR spectra.