Assemblies between rigid linear ligands of 1-methyl-1‘,2-bis(4-pyridyl)ethene (mpe) and Co(NCS)2 afford three isomeric framework networks with an identical chemical composition of [Co(mpe)2(NCS)2]∞ and different topological features depending on the assembly conditions such as solvents, concentration, and diffusion rate. Each of them consists of perpendicularly interpenetrating grid layers (1), mutually interpenetrating CdSO4 type 3-D frames and square grid layers (2), and closely stacked grid layers (3), respectively. The structures of 1 and 2 exhibit solid-to-solid transformation behavior to thermodynamically stable forms of 2 and 3, respectively.