Abstract The new compound [(Crypt-2.2.2)H2]I8 has been prepared by the reaction of [(Crypt-2.2.2)H2](I3)2 with iodine in methanol. It crystallizes in the orthorhombic space group Pbcn with a = 11.476 (2), b = 13.589 (2), c = 22.888 (2) Å and Z = 4. The crystal structure has been refined to RF = 0.031 for 1618 reflections. It may be described as a layerlike packing of octaiodide anions I82-and diprotonated 2.2.2-Crypt as cations. The non planar octaiodide anion is built up from two triiodide groups and a bridging iodine molecule.Tris(1, 10-phenanthroline)nickel(II) octaiodide bis(chloroform) crystallizes in the monoclinic space group P21/n with a = 11.683 (8), b = 21.717 (8), c = 20.752 (5) Å, β = 95.03 (5)° and Z = 4 formula units. The crystal structure has been refined to RF = 0.058 for 3894 reflections. The structure consists of two chloroform molecules, octahedrally coordinated complex cations [Ni(phen)3]2+ and nonplanar octaiodide anions I82- each composed of two asymmetric triiodide units I3- weakly associated with an elongated bridging iodine molecule I2.The already known structure of bis(N-methylurotropinium) octaiodide, (UrMe)2I8, has been verified and more accurate crystal data have been collected. The crystal structure has been refined to RF = 0.045 for 1908 reflections. The compound crystallizes in the monoclinic space group P21/c with a = 11.302 (2), b = 9.850 (2), c = 14.188 (2) Å , β = 92.59 (1)° and Z = 2. The anion has the shape of a stretched Z.The structure of bis(N-ethylurotropinium) octaiodide (UrEt)2I8 has been determined and a new configuration (I3-, I5-) for octaiodide ions between Z (I3- · I2 ·I3-) and a “broken” configuration (I3-, I5-) has been observed. The compound crystallizes in the triclinic space group P1̄ with a = 9.741 (3), b = 11.815 (3), c = 15.426 (3) Å, α = 91.80 (2), β = 107.14 (2), γ = 90.04 (2)° and Z = 2. The crystal structure has been refined to RF = 0.037 for 3657 reflections.