A pillared framework coordination polymer based on the Cd3(μ3-OH) unit: poly[[(μ4-5-aminotetrazolato-κ(4)N(1):N(2):N(3):N(4))chlorido-μ3-hydroxido-(μ3-isonicotinato-κ(3)N: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 Cs 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 μ1,2 or μ2,3/μ3,4 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.