catena-Poly[potassium [copper(II)-μ-isothiocyanato-μ-N-salicylidene-β-alaninato(2–)]]

The title polymeric compound, catena-poly­[dipotassium [bis­[μ-N-salicyl­idene-β-alaninato(2−)]-κ⁴O,N,O′:O′′;κ⁴O′′:O,N,O′-dicopper(II)]-di-μ-iso­thio­cyanato-κ²N:S;κ²S:N], {K[Cu(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 Cu^II 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.