Abstract

The synthesis, crystal structure, and properties of novel ternary inclusion compounds formed by the insertion of protonated bis(quinuclidine †) guests into urea-bromide and urea-iodide anionic hosts are reported. (Urea2[quinuclidine2H]+Br-), 1, and (urea2[quinuclidine2H]+I-), 2, are monoclinic, space group C2. ‡ The cell parameters for 1 are a = 19.323(8), b = 7.145(3), c = 8.566(4), ? = 112.19(3), dcalc = 1.284 and Z = 4, considering 472 reflections; for 2 they are a = 20.51(11), b = 7.34(3), c = 8.17(4), ? = 111.81(8), dcalc = 1.369, Z = 4, considering 716 reflections. In the two structures each urea molecule interacts with adjacent urea molecules via N-H ? O hydrogen bonds forming a ribbon-like arrangement. The ribbons are linked through halide ions by N-H ? X hydrogen bonds forming layered structures. The distances between the layers are 10.301 Å for 1 and 8.566 Å for 2. The compounds may be described as commensurate species. Conductivity values determined for 1 and 2 at room temperature are 1.19 × 10-5 and 8.66 × 10-7 (? cm)-1, and they increase with temperature. Aspects of the thermal stability of the products are discussed.