We synthesized new porous coordination polymers (PCPs) {Ln(III)[Co-III(dcbpy)(3)]center dot nH(2)O} (Ln = Nd3+, Gd3+; H(2)dcbpy = 4,4'-dicarboxy-2,2'-bipyridine) and characterized them by X-ray diffraction and vapor-adsorption measurements. These three Ln-Co-based PCPs have similar rock-salt types and highly symmetrical porous structure and show a reversible structural collapse regeneration accompanied by water-vapor desorption adsorption. Similar structural regeneration was also observed for the Gd-Co PCP upon exposure to MeOH and CH3CN vapors, whereas the remaining two PCPs barely responded to organic vapors.