title: Divalent metal vinylphosphonate layered materials: compositional variability, structural peculiarities, dehydration behavior, and photoluminescent properties.
abstract: A family of M-VP (M = Ni, Co, Cd, Mn, Zn, Fe, Cu, Pb; VP = vinylphosphonate) and M-PVP (M = Co, Cd; PVP = phenylvinylphosphonate) materials have been synthesized by hydrothermal methods and characterized by FT-IR, elemental analysis, and thermogravimetric analysis (TGA). Their structures were determined either by single crystal X-ray crystallography or from laboratory X-ray powder diffraction data. The crystal structure of some M-VP and M-PVP materials is two-dimensional (2D) layered, with the organic groups (vinyl or phenylvinyl) protruding into the interlamellar space. However, the Pb-VP and Cu-VP materials show dramatically different structural features. The porous, three-dimensional (3D) structure of Pb-VP contains the Pb center in a pentagonal pyramid. A Cu-VP variant of the common 2D layered structure shows a very peculiar structure. The structure of the material is 2D with the layers based upon three crystallographically distinct Cu atoms; an octahedrally coordinated Cu(2+) atom, a square planar Cu(2+) atom and a Cu(+) atom. The latter has an unusual co-ordination environment as it is 3-coordinated to two oxygen atoms with the third bond across the double bond of the vinyl group. Metal-coordinated water loss was studied by TGA and thermodiffractometry. The rehydration of the anhydrous phases to give the initial phase takes place rapidly for Cd-PVP but it takes several days for Co-PVP. The M-VP materials exhibit variable dehydration-rehydration behavior, with most of them losing crystallinity during the process.
authors.affiliation: Departamento de Química Inorgánica, Universidad de Málaga, Campus Teatinos S/N. 29071-Málaga, Spain.
authors.forename: Rosario M P
authors.initials: RM
authors.lastname: Colodrero
authors.forename: Aurelio
authors.initials: A
authors.lastname: Cabeza
authors.forename: Pascual
authors.initials: P
authors.lastname: Olivera-Pastor
authors.forename: Duane
authors.initials: D
authors.lastname: Choquesillo-Lazarte
authors.forename: Juan M
authors.initials: JM
authors.lastname: Garcia-Ruiz
authors.forename: Adele
authors.initials: A
authors.lastname: Turner
authors.forename: Gheorghe
authors.initials: G
authors.lastname: Ilia
authors.forename: Bianca
authors.initials: B
authors.lastname: Maranescu
authors.forename: Konstantinos E
authors.initials: KE
authors.lastname: Papathanasiou
authors.forename: Gary B
authors.initials: GB
authors.lastname: Hix
authors.forename: Konstantinos D
authors.initials: KD
authors.lastname: Demadis
authors.forename: Miguel A G
authors.initials: MA
authors.lastname: Aranda