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. © 2019 American Chemical Society.