Coordination Chemistry of Anticrowns. Isolation of the Chloride Complex of the Four-Mercury Anticrown {[( o , o ′-C 6 F 4 C 6 F 4 Hg) 4 ]Cl} − from the Reaction of o , o ′-Dilithiooctafluorobiphenyl with HgCl 2 and Its Transformations to the Free Anticrown and the Complexes with o -Xylene, Aceto