Coordination Chemistry of Anticrowns. Interaction of the Perfluorinated Three-Mercury Anticrown (o-C6F4Hg)3 with Azacrowns

The interaction of the three-mercury anticrown (o-C6F4Hg)3 (1) with various azacrowns such as 2,9,16,23-tetra-tert-butylphthalocyanine (TBPC), octaazapentacyclooctacosane (OAOC), 1,4,8,11-tetraazacyclotetradecane (cyclam), and N,N,N-trimethyl-1,3,5-triazacyclohexane (TACH) has been studied. It has been shown that the reaction of 1 with TBPC in CH2Cl2 at 20°C affords 1:1 complex {[(o-C6F4Hg)3]­(TBPC)} (2) according to elemental analysis, and the interaction of 1 with OAOC·0.5H2O in ether results in the formation of complex {[(o-C6F4Hg)3]2(OAOC)­(H2O)2} (3). The molecules of azacrown and water in 3 are located between the parallel planes of two mercuramacrocycles strongly laterally shifted relative to one another and are bonded to them through Hg–N and Hg–O secondary interactions. An especially interesting complex, [(CH2)10(NH2)2(NH)2]­{[(o-C6F4Hg)3]2Cl2} (4), has been obtained by the reaction of 1 with cyclam [(CH2)10(NH)4] in CH2Cl2 at 20 °C. The complex has a structure of a double-decker sandwich wherein two chloride anions and the diprotonated molecule of cyclam as a counterdication are disposed between the parallel planes of two molecules of 1. Each chloride anion in 4 is η3-coordinated with the Hg centers of the neighboring anticrown, whereas the NH and NH2+ groups of the diprotonated cyclam form three H-bonds with each of these chloride anions. The mechanism of the formation of this unusual sandwich is discussed. The synthesis and structure of an analogous complex, [(CH2)10(NH2)2(NH)2]­{[(o-C6F4Hg)3]­Cl2}·2­(CH3)2CO, which forms polydecker sandwiches in the crystal are also described. The interaction of 1 with cyclam in aqueous THF at 20°C gives a complex, {[(o-C6F4Hg)3]­[(CH2)10(NH)4]­(THF)­(H2O)} (6), also forming infinite polymeric chains in the crystal. A characteristic structural feature of 6 is the presence in each its monomeric unit of a bipyramidal fragment formed by 1 and two different η3-coordinated Lewis bases (THF and water). From the reaction of 1 with TACH, a complex having a unique double-cage structure, {[(o-C6F4Hg)3]­(TACH)2} (7), has been isolated.