Tetrakis(2‐amino‐5‐methyl‐1,3,4‐thia­diazo­le‐N3)­chloro­copper(II) chloride monohydrate and tetrakis(2‐amino‐5‐ethyl‐1,3,4‐thia­diazo­le‐N3)­chlorocopper(II) chloride

The structures of the title compounds, CuCl(C₃H₅N₃S)₄]Cl·H₂O, (I), and CuCl(C₄H₇N₃S)₄]Cl, (II), comprise square‐pyramidal Cu centres with four N‐bound organic ligands filling the base positions, a Cl atom in the apical position and a Cl^? as a free counter‐ion. The cation and free chloride ion in (II) have fourfold crystallographic symmetry. Hydro­gen‐bonding associations from the 2‐amino H atoms dominate both structures, with the principal acceptors being the chlorides, although in (I), the N4 atoms are also involved. Furthermore, (I) is a hydrate, with the water mol­ecule participating in the hydrogen‐bonding network.