Synthesis, characterization, and structural analyses of two cyanide-bridged bimetallic complexes

The crystal structures of two bimetallic cyanide-bridged lanthanide (Ln) complexes were obtained by means of three-dimensional single-crystal X-ray diffraction techniques. The isostructural complexes (DMF)(4)(H2O)(3)LaFe(CN)(6). H2O (I) and (DMF)(4)(H2O)(3)CeFe(CN)(6). H2O (II) crystallize in the monoclinic system with Z = 4 having respective lattice constants of a = 17.660(2), 17.633(4); b = 8.952(1), 8.920(2); c = 20.017(2), 19.950(4) Angstrom; and beta = 95.68(1), 95.72(3). In each complex, the coordination about the central lanthanide ion is eight in a square antiprism arrangement while the coordination about the iron(III) ion is six, oriented octahedrally. Molecules in the crystal lattice of each complex are held together by normal van der Waals forces and a network of hydrogen bonding. Characterization includes physical property determinations, conoscopic studies, thermal gravimetric analyses (TGA), and IR spectrometric identifications. Select geometric parameters are tabulated and a synthesis of these compounds is presented. (C) 2000 Elsevier Science B.V. All rights reserved.