Two novel mixed 1D–2D coordination polymers based on 2D [Ln(4,4′-bpdo)2(NO3)2(H2O)2]n+ sheets and 1D [Ln2(4,4′-bpdo)2(C4AS)(NO3)(H2O)9]n chains (Ln = Sm for 1 and Ln = Nd for 2) sustained by π⋯π interactions and lattice water facilitated hydrogen bonds have been established. The chains are arranged such that the p-sulfonatocalix[4]arene anions occupy the cavities of the 2D coordination polymer, and so act as guests rather than as hosts, which is their more usual role.