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　CdII　atoms　and　the　O　and　H　atoms　located　on　a　mirror　plane.　The　other　crystallographically　independent　CdII　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.　©　2014　International　Union　of　Crystallography.