title: Formation of metal-anion arrays within layered perovskite hosts. Preparation of a series of new metastable transition-metal oxyhalides, (MCl)LaNb(2)O(7) (M = Cr, Mn, Fe, Co).
abstract: A new series of transition-metal oxyhalides (MCl)LaNb(2)O(7) (M = Cr, Mn, Fe, Co) have been prepared by a simple topochemical route. Layered perovskite hosts (ALaNb(2)O(7), A = Li, Na, K or Rb) were reacted with the corresponding anhydrous metal halides under mild reaction conditions (<400 degrees C). The compounds were examined by X-ray powder diffraction; the series appears to be isostructural with (CuCl)LaNb(2)O(7), and the layer spacings, with the exception of M = Co, follow the trend expected from transition-metal cationic radii. Thermal analysis with differential scanning calorimetry (DSC) shows the materials to be metastable where all four compounds decompose exothermically above 690 degrees C.
authors.affiliation: Department of Chemistry and the Advanced Materials Research Institute, University of New Orleans, New Orleans, Louisiana 70148-2820, USA.
authors.forename: Liliana
authors.initials: L
authors.lastname: Viciu
authors.forename: Gabriel
authors.initials: G
authors.lastname: Caruntu
authors.forename: Nicolas
authors.initials: N
authors.lastname: Royant
authors.forename: Julien
authors.initials: J
authors.lastname: Koenig
authors.forename: Weilie L
authors.initials: WL
authors.lastname: Zhou
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Kodenkandath
authors.forename: John B
authors.initials: JB
authors.lastname: Wiley