Nitroaromatic-detecting Layered Cadmium Cyclohexyldicarboxylate Coordination Polymers with Long-Spanning Dipyridyl Pillaring Ligands

Three new divalent cadmium coordination polymers containing cyclohexyldicarboxylate and pillaring dipyridylamide ligands have been prepared and structurally characterized via single-crystal X-ray diffraction. All three compounds exhibited layered structures, but with different topologies and interpenetration schemes. [Cd-2(12chedc)(2)(ebin)(H2O)(2)](n)(1) [12chedc = 1,2-cyclohex-4-ene-dicarboxylate, ebin = ethylenediamine(bis)isonicotinamide] displays a 2D 3,4-connected net with (4(2)6)(4(2)6(3)8) topology, also known as the V(2)O(5)structural type. {[Cd(13cdc)(ebin)]center dot H2O}(n)(2) (13cdc =cis-1,3-cyclohexanedicarboxylate) showed a rare 2D + 2D -> 3D parallel polycatenated system of looped layer networks. {[Cd(13cdc)(hbn)]center dot H2O}(n)(3) [hbn = hexanediamine(bis)nicotinamide] manifests a (4(2)6)(4(2)6(7)8) network, also known as the 3,5L2 net. All three materials were assayed as fluorescent "turn-off" sensors for the detection of nitrobenzene in solution. Thermal decomposition behavior of the new phases is also discussed.