A　cationic　lanthanide　metalloligand　with　3　dangling　carboxylate　groups　on　its　periphery　co-assembles　with　nitrate　into　a　porous　thermochromic　solid　responsive　to　both　external　cations　and　anions,　owing　to　the　presence　of　exchangeable　NO3-　as　well　as　cation　cavities　arising　from　cooperative　orientation　of　free　carboxylate　groups.　An　especially　interesting　feature　is　the　structural　memory　effect　during　crystallization　exhibited　by　the　metalloligand,　even　after　dissolution　and　binding　to　secondary　cations　(Cu2+,　Cd2+...).　Moreover,　the　porous　solid　can　undergo　ion-exchange　with　various　anions,　leading　to　tunable　thermochromic　temperature　and　color　range.　©　2016　The　Royal　Society　of　Chemistry.