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The reaction of anhydrous [12]crown-4 with a 1:1 ethanol adduct of the three-mercury anticrown (o-C 6 F 4 Hg) 3 (1) under Ar results in the formation of a double-decker sandwich complex {[(o-C 6 F 4 Hg) 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-C 6 F 4 Hg) 3 ] 2 ([12]crown-4)(H 2 O) 2 } (5), containing one crown ether molecule and two molecules of H 2 O 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 the water protons forms the hydrogen bond with the oxygen atom of the crown ether. An additional contribution in the bonding is made by the interaction of one of the Hg centers of each anticrown unit with the nearest oxygen atom of [12]crown-4. The complex of analogous composition and close structure is formed in the reaction of 1 with aqueous [18]crown-6. However in this sandwich, {[(o-C 6 F 4 Hg) 3 ] 2 ([18]crown-6)(H 2 O) 2 } (6), both protons of each water species are involved in the formation of the H-bonds with the crown ether, while the bonding of each mercuramacrocycle to the crown ether is accomplished due to the coordination of two of its Hg atoms with two oxygen atoms of the crown compound. From the interaction of 1 3 EtOH with 1,3,5-trioxane, a 1:1 complex, {[(o-C 6 F 4 Hg) 3 ](CH 2 O) 3 } (7), having a cage structure, has been isolated. The synthesized adducts are the first complexes of crown ethers with an anticrown.

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The interaction of the three-mercury anticrown (o-C 6 F 4 Hg) 3 (1) with a 5-fold excess of [9]thiacrown-3 gives a 1:1 complex, {[(o-C 6 F 4 Hg) 3 ](C 2 H 4 S) 3 } (2), representing a polydecker bent sandwich in the crystal. Every thiacrown ligand in this sandwich is bound to the nearest anticrown units by two sulfur atoms, each of which interacts with a single Hg center of the neighboring molecule of 1. When the reaction of 1 with [9]thiacrown-3 is conducted at a 2-fold excess of 1, a complex, {[(o-C 6 F 4 Hg) 3 ] 2 (C 2 H 4 S) 3 } (3), containing two molecules of the mercury anticrown per one thiacrown molecule is produced, and this adduct has a double-decker sandwich structure. Here, all three sulfur atoms of the thiacrown are involved in the bonding to the molecules of the anticrown, two of them being cooperatively coordinated each by all three Lewis acidic Hg sites of the adjacent anticrown molecule, whereas the third sulfur atom interacts again with a single Hg center. From the reaction of 1 with 1,3,5-trithiane, a 1:1 complex, {[(o-C 6 F 4 -Hg) 3 ](CH 2 S) 3 } (4), has been isolated. This complex, in contrast to 2, has a discrete, cage structure. The synthesized adducts are the first complexes of crown compounds with an anticrown.

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The paper reports the first X-ray diffraction data evidencing the cyclic trimeric structure of the earlier synthesized octafluoro-o,o′-biphenylenemercury (8), being of considerable interest as a potential anticrown. The conclusion on the trimeric (o,o′-C 6 F 4 C 6 F 4 Hg) 3 structure of this mercuracycle is based on an X-ray structural analysis of its o-xylene and acetonitrile complexes {[(o,o′-C 6 F 4 C 6 F 4 Hg) 3 ](o-Me 2 C 6 H 4 ) 2 } (9) and {[(o,o′-C 6 F 4 C 6 F 4 Hg) 3 ](MeCN) 3 } (10), which were obtained from 8 in an analytically pure state and fully characterized. Complex 9 contains two o-xylene species per one molecule of 8 and forms in the crystal infinite chains consisting of alternating mercuramacrocycle units and bridging o-xylene ligands. One more o-xylene molecule in each macrocyclic fragment of the chain serves as a terminal ligand. Both bridging and terminal molecules of o-xylene are coordinated in all cases with only one Hg site of the corresponding mercuracycle. The back transformation of complex 9 into 8 and o-xylene occurs on its heating in a vacuum at 100−120°C for 2 h. In contrast to 9, complex 10, containing three acetonitrile ligands per one molecule of 8, has a discrete structure in the crystal. In this complex, two of three acetonitrile species are bonded to one and the same Hg center of 8, whereas the third MeCN species is coordinated with the other Hg atom of the mercuramacrocycle.

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