Complexation of [12]Crown-4, [18]Crown-6, and 1,3,5-Trioxane with Cyclic Trimeric Perfluoro-o-phenylenemercury. Synthesis and Structures of the First Complexes of Crown Ethers with an Anticrown

The reaction of anhydrous [12]crown-4 with a 1:1 ethanol adduct of the three-mercury anticrown (o-C6F4Hg)3 (1) under Ar results in the formation of a double-decker sandwich complex {[(o-C6F4Hg)3]2([12]crown-4)} (4). The molecule of the crown ether in 4 is located between the mutually parallel planes of two mercury macrocycles and is coordinated to each of them through Hg−O secondary interactions. In the crown ether ligand, all four oxygen atoms are involved in the bonding to the molecules of 1, while in each anticrown species only two Hg centers take part in the coordination. If aqueous [12]crown-4 is used in the reaction with 1, the other double-decker sandwich, {[(o-C6F4Hg)3]2([12]crown-4)(H2O)2} (5), containing one crown ether molecule and two molecules of H2O in the space between the planes of the anticrown units, is produced. Every water molecule in this supramolecular aggregate is cooperatively bound through the oxygen atom by three Lewis acidic Hg sites of the neighboring anticrown, whereas one of ...