| Abstract |
This work describes the crystal structures of two Mg dimers supported by dianionic trans-disubstituted Bn(2)Cyclam ligands (1,8-dibenzyl-1,4,8,11-tetraazacyclotetradecane). Mg-2(Bn(2)Cyclam)I-2 (1) crystallizes in the monoclinic space group P2(1)/c with half-molecule in the asymmetric unit. The two metal centers and the two N-amido donors of the cyclam ring define a four-member Mg2N2 metallacycle. The metals coordination spheres are completed by one amine of the macrocycle and one iodide defining a trigonal pyramidal coordination geometry. Mg-2(Bn(2)Cyclam)\mu-H\\mu-F-C6F4\2BC(6)F(5) (2) crystallizes in the monoclinic space group P2(1)/c with half-molecule in the asymmetric unit. Compound 2 is a rare example of a zwitterionic species of the type [Mg-2(Bn(2)Cyclam)](2+) with two [HB(C6F5)(3)](-) anions coordinating in a k(3)-H,F,F tridentate fashion. This compound also displays bridging N-amido ligands that bind the two Mg atoms in a Mg2N2 arrangement analogous to 1, promoting a capped square pyramidal coordination geometry. At a supramolecular level C-H center dot center dot center dot I and C-H center dot center dot center dot F hydrogen bonds as well as CH/pi and F center dot center dot center dot F interactions are responsible for the crystal packing. (C) 2012 Elsevier B.V. All rights reserved. |
