Reactions of cobalt(II) nitrate or zinc(II) nitrate, tetrasodium p-sulfonatothiacalix[4]arene (Na4H4TCAS), and methylviologen dihexafluorophosphate (MV(PF6)2) afforded two isomorphous complexes, {[M(H2O)6]2 + [MV]2 + [(MV)2M2(H2O)4(H2TCAS)2]4 - }·14H2O (M = Co, 1; Zn, 2). In these two complexes, each two thiacalixarenes form a dimer with Ci symmetry through the coordination of sulfonate groups, and the above dimers further extend their structures through second-sphere coordination and π...π stacking interactions into three-dimension nets. [ABSTRACT FROM AUTHOR]