Nitroaromatic-detecting cadmium cyclohexyldicarboxylate coordination polymers with bis(4-pyridylmethyl)piperazine coligands and unprecedented 2D and 3D topologies

Abstract

Hydrothermal reaction of cadmium nitrate, bis(4-pyridylmethyl)piperazine (4-bpmp), and a variety of cyclohexyldicarboxylate ligands generated three new coordination polymer solids that were structurally characterized via single-crystal X-ray diffraction. [Cd(cis-13cdc)(4-bpmp)]_n (1, cis-13cdc = cis-1,3-cyclohexanedicarboxylate) shows a sawtooth (4,4) grid topology. [Cd₂(trans-12cdc)₂(4-bpmp)]_n (2, trans-12cdc = trans-1,2-cyclohexanedicarboxylate) displays a unique 4,5-connected layered (4⁶)(4⁶6⁴) topology with embedded [Cd₂(trans-12cdc)₂] ribbon motifs. {[Cd(cis-12chedc)(4-bpmp)]·0.25H₂O}_n (3, cis-12chedc = cis-1,2-cyclohex-4-enedicarboxylate) manifests a 3D 3,5-connected self-penetrated network with an unprecedented (4²6)(4²6⁵8³) topology. Thermal decomposition, luminescent, and nitroaromatic detection properties of these three new materials are discussed.