Abstract: | The title polymeric compound, catena‐polydipotassium bisμ‐N‐salicylidene‐β‐alaninato(2−)]‐κ4O,N,O′:O′′;κ4O′′:O,N,O′‐dicopper(II)]‐di‐μ‐isothiocyanato‐κ2N:S;κ2S:N], {KCu(NCS)(C10H9NO3)]}n, consists of isothiocyanato(N‐salicylidene‐β‐alaninato)copper(II)]− anions connected through the two three‐atom thiocyanate (μ‐NCS) and the two anti,anti‐μ‐carboxylate bridges into infinite one‐dimensional polymeric anions, with coulombically interacting K+ counter‐ions with coordination number 7 constrained between the chains. The CuII atoms adopt a distorted tetragonal–bipyramidal coordination, with three donor atoms of the tridentate Schiff base and one N atom of the bridging μ‐NCS ligand in the basal plane. The first axial position is occupied by a thiocyanate S atom of a symmetry‐related μ‐NCS ligand at an apical distance of 2.9770 (8) Å, and the second position is occupied by an O atom of a bridging carboxylate group from an adjacent coordination unit at a distance of 2.639 (2) Å. |