A one‐dimensional ladder‐like six‐coordinate cadmium polymer: catena‐poly[bis[(S)‐2‐methylpiperazine‐1,4‐diium] [bis[trichloridocadmium(II)]‐di‐μ3‐chlorido]]

The crystal structure of the title compound {(C₅H₁₄N₂)₂[Cd₂Cl₈]}_n, (I), consists of hydrogen‐bonded 2‐methylpiperazinediium (H₂MPPA²⁺) cations in the presence of one‐dimensional polymeric {[CdCl₃(μ₃‐Cl)]²⁻}_n anions. The Cd^II centres are hexacoordinated by three terminal chlorides and three bridging chlorides and have a slightly distorted octahedral CdCl₃(μ₃‐Cl)₃ arrangement. The alternating CdCl₆ octahedra form four‐membered Cd₂Cl₂ rings by the sharing of neighbouring Cd–Cl edges to give rise to extended one‐dimensional ladder‐like chains parallel to the b axis, with a Cd...Cd distance of 4.094 (2) Å and a Cd...Cd...Cd angle of 91.264 (8)°. The H₂MPPA²⁺ cations crosslink the [CdCl₃(μ₃‐Cl)]_n chains by the formation of two N—H...Cl hydrogen bonds to each chain, giving rise to one‐dimensional ladder‐like H₂MPPA²⁺–Cl₂ hydrogen‐bonded chains [graph set R₄²(14)]. The [CdCl₃(μ₃‐Cl)]_n chains are interwoven with the H₂MPPA²⁺–Cl₂ hydrogen‐bonded chains, giving rise to a three‐dimensional supramolecular network.