Naphthalenediimides,　an　attractive　class　of　electron-deficient　organic　dyes　with　rich　redox　and　photoredox　properties,　have　been　investigated　extensively　as　building　blocks　for　coordination　networks　or　metal-organic　frameworks　in　recent　decades.　However,　most　of　the　available　work　has　focused　on　d-block　metal　cations　rather　than　f-block　lanthanide　ions,　whose　complexes　exhibit　a　large　variability　in　coordination　numbers.　In　this　article,　four　coordination　polymers　composed　of　naphthalenediimides　and　lanthanide　cations,　namely　catena-poly[[[tris(nitrato-kappa　O-2,O＇)lanthanide]-bis{mu-N,N＇-bis[(1-oxidopyridin-1-ium-3-yl)methyl]-1,8　4,5-naphthalenetetracarboxdiimide-kappa　O-2:O＇}-[tris(nitrato-kappa　O-2,O＇)lanthanide]-mu-N,N＇-bis[(1-oxidopyridin-1-ium-3-yl)methyl]-1,8:4,5-naphthalenetetracarboxdiimide-kappa　O-2:O＇]　methanol　disolvate],　{[Ln(C26H16N4O4)(1.5)-(NO3)(3)]center　dot　CH3OH}(n),　with　Ln　=　Eu,　1,　Gd,　2,　Dy,　3,　and　Er,　4,　have　been　successfully　synthesized　under　hydrothermal　conditions.　Single-crystal　X-ray　diffraction　analyses　revealed　that　the　four　compounds　are　isomorphic　and　that　each　asymmetric　unit　contains　one　nine-coordinated　Ln　centre,　one　and　a　half　diimide　ligands,　three　nitrate　anions　and　one　uncoordinated　methanol　molecule.　In　addition,　each　metal　centre　is　surrounded　by　nine　O　atoms　in　a　distorted　tricapped　trigonal-prismatic　geometry.　Two　centres　are　bridged　by　two　cis　ligands　to　form　a　ring,　which　is　further　bridged　by　trans　ligands　to　generate　one-dimensional　chains.　Neighbouring　chains　are　stacked　via　pi-pi　interactions　between　pyridine　rings　to　give　a　two-dimensional　structure,　which　is　stabilized　by　pi-pi　interactions　between　naphthalene　rings,　forming　the　final　three-dimensional　supermolecular　network.　Solid-state　optical　diffuse-reflectance　spectral　studies　indicate　that　compound　4　is　a　potential　wide　band　gap　semiconductor.