Simple layered or complex self-penetrated networks in cadmium homophthalate coordination polymers containing 1,3-bis(4-pyridyl)propane

► Cadmium coordination polymers with homophthalate (hmph) and dipyridylpropane (dpp). ► Cd(hmph)(dpp)n (1) has a zig-zag (4,4) layer topology with simple AAA stacking. ► {[Cd6(hmph)4(dpp)11(H2O)4](ClO4)4·4H2O}n (2) has a complicated self-penetrated net.