Control of topology in luminescent nitrobenzene-detecting cadmium camphorate polymers via hydrogen-bonding capable dipyridyl ligands

Hydrothermal reaction of cadmium nitrate, D-camphoric acid (D-camH(2)), and a hydrogen-bonding capable dipyridyl ligand resulted in coordination polymers whose dimensionalities and topologies depend critically on the pyridyl nitrogen donor disposition and tether length. The four new phases were characterized by single crystal X-ray diffraction; racemization of the camphorate ligands was observed in three cases. {[Cd(DL-cam)(hdin)](n) (1, hdin = N,N'-(hexane-l,6-diyl)diisonicotinamide) shows a 2D sawtooth (4,4) grid structure. [Cd-2(D-cam)(2)(3-bpmp)(H2O)(2)](n) (2, 3-bpmp = bis(3-pyridylmethyl)piperazine) displays a 1D ladder coordination polymer structure with [Cd(D-cam)(H2O)](n) uprights pillared by 3-bpmp rungs. The minor product [Cd-2(DL-cam)(2)(3-bpmp)](n) (3) manifests a {Cd2O2} dimer-based 6-connected 3D 4(12)6(3) pcu topology. [Cd-2(DL-cam)(2)(4-bpmp)](n) (4, 4-bpmp = bis(4-pyridylmethyl)piperazine) also displays a dimer-based 6-connected 3D net, but witha 4(4)6(10)8 mab self-penetrated net due to cross-pillaring of the pyridyl ligands. Thermal and luminescent properties of were investigated; compounds 2 and 4 showed very good ability to detect nitrobenzene in ethanol suspension via luminescence quenching. (C) 2018 Elsevier B.V. All rights reserved.