CRYSTAL-STRUCTURES OF THE [2.2.2]CRYPTATE S [CD(CRYPTAND 222)][CDCL4]AND [HG(CRYPTAND 222)][HG2CL6] WITH 8-COORDINATED METAL-IONS

Reactions of [2.2.2]cryptand, 22,24-Hexaoxa-1,10-diazabicyclo-[8.8.8]h exacosane, (''cryptand 222'') with cadmium chloride and mercuric chlor ide yielded crystals of [Cd(cryptand 222)][CdCl4] (1) and [Hg(cryptand 222)][Hg2Cl6] (2). 1 crystallizes tetragonally, space group P(4)2/n, Z = 4, a = 1239.8(2), c = 1801.2(8) pm; 2 is monoclinic, space group P 2/n, Z = 2, a = 1060.3(3), b = 955.2(2), c = 1607.0(3) pm, and beta = 108.85(2)degrees. In the cations of both complexes the metal ions are enclosed in the bicyclic ligand and show 8-coordination to its six oxy gen and two nitrogen atoms, the coordination polyhedron is a distorted cube for 1 and a bicapped trigonal antiprism for 2. The anion of 2 is dimeric; the two mercury atoms are connected via chlorine bridges wit h Hg-Cl distances of 258 and 278 pm, the Hg-Cl bond lengths to the two terminal chloro ligands being shorter at 236 and 238 pm.