Anionic Complexes of the Perfluorinated Three‐Mercury Anticrown (o,o’‐C₆F₄C₆F₄Hg)₃. Dependence of the Anion Coordination Type on Counter‐Cation in Case of Chloride and Bromide Anions

Abstract

The interaction of the macrocycle (o,o'-C 6 F 4 C 6 F 4 Hg) 3 ( 1) containing three mercury centres with arylphosphonium salts ([Ph 4 P]Cl or [Ph 4 P]Br) yields halide complexes, [Ph 4 P]{[(o,o'-C 6 F 4 C 6 F 4 Hg) 3 ](η 1 :η 1 -X)} (X = Cl, Br) having infinite polymer chain structure in the crystal. In both adducts, the halide anion is situated outside of the cavity of the three-mercury anticrown 1 and bridged by two mercury centres of neighbouring anticrown moieties. At the same time, when mercuracycle 1 interacts with tetraalkylammonium salts ([ n Bu 4 N]Cl or [ n Bu 4 N]Br), then the discrete 1 : 1 complexes [ n Bu 4 N]{[(o,o'-C 6 F 4 C 6 F 4 Hg) 3 ](η 3 -X)} (X = Cl, Br) of completely different structure are formed. In these halide complexes the anion is located inside the cavity of macrocycle 1 and coordinates the three mercury atoms symmetrically. The synthesized halide complexes [ n Bu 4 N]{[(o,o'-C 6 F 4 C 6 F 4 Hg) 3 ](η 3 -X)} (X = Cl, Br) are the first example of complexes of the macrocycle 1 where it behaves as anticrown.