A pillared framework coordination polymer based on the Cd3(μ3‐OH) unit: poly[[(μ4‐5‐aminotetrazolato‐κ4N1:N2:N3:N4)chlorido‐μ3‐hydroxido‐(μ3‐isonicotinato‐κ3N:O:O′)dicadmium(II)] 0.14‐hydrate]

The title coordination polymer, {Cd₂(CH₂N₅)(C₆H₄NO₂)Cl(OH)]·0.14H₂O}_n, (I), was synthesized by the reaction of cadmium acetate and N‐(1H‐tetrazol‐5‐yl)isonicotinamide in aqueous ammonia, using hydrochloric acid to adjust the pH. Under hydrothermal conditions, N‐(1H‐tetrazol‐5‐yl)isonicotinamide slowly hydrolyzes to form isonicotinic acid (Hisonic) and 5‐aminotetrazole (Hatz). The deprotonated form of isonicotinic acid (denoted isonic) acts as a bridging ligand in the structure. The polymer crystallizes in the monoclinic space group C2/m. In the structure, there is one Cd₃(μ₃‐OH) unit of C_s symmetry, with one of the Cd^II atoms and the O and H atoms located on a mirror plane. The other crystallographically independent Cd^II cation is located on an inversion centre. Each edge of the Cd₃(μ₃‐OH) isosceles triangle is bridged by an atz ligand in a μ_1,2 or μ_2,3/μ_3,4 mode. The Cd₃(μ₃‐OH) units are laced around with a belt of chloride ligands. The belts are further connected into undulating layers via weak inter‐belt Cd—Cl bonds. The two organic ligands reside across mirror planes. The construction of a three‐dimensional framework is completed by the pillaring isonic ligand. Water molecules partially occupy the voids of the framework.