title: Intercalation of an oxalatooxoniobate complex into layered double hydroxide and layered zinc hydroxide nitrate.
abstract: A Zn/Al layered double hydroxide with molar ratio of 3 was prepared by coprecipitation in alkaline pH and used as a matrix to intercalate the ionic complex diaquadioxalatooxoniobate(V) (DDON), derived from NH(4)[NbO(C(2)O(4))(2)(H(2)O)(2)]2H(2)O. In a similar way, the layered zinc hydroxide nitrate, Zn(5)(OH)(8)(NO(3))(2)2H(2)O, was synthesized, preexpanded with azelate ions ((-)OOC(CH(2))(7)COO(-)), and then intercalated with the niobium complex. For both layered matrices, the results from X-ray powder diffractometry, Fourier transform infrared spectroscopy, and thermal analysis (TG/s-DTA) indicate the presence of the oxalate ion. In addition, results from X-ray photoelectron and Raman spectroscopy indicate the presence of the niobium center bonded to oxygen atoms. Finally, diffuse reflectance UV-vis spectroscopy suggests that the niobium centers are coordinated to oxalate ions. This is the first report of the intercalation of niobium into a layered matrix.
authors.affiliation: Centro de Pesquisas em Química Aplicada, Chemistry Department, Federal University of Paraná, P.O. Box 19081, Curitiba 81531-990, Pr, Brazil.
authors.forename: Gregorio Guadalupe Carbajal
authors.initials: GG
authors.lastname: Arizaga
authors.forename: José Eduardo Ferreira da Costa
authors.initials: JE
authors.lastname: Gardolinski
authors.forename: Wido Herwig
authors.initials: WH
authors.lastname: Schreiner
authors.forename: Fernando
authors.initials: F
authors.lastname: Wypych