title: Structural Redetermination and Photoluminescence Properties of the Niobium Oxyphosphate (NbO)2P4O13.
abstract: The structure of (NbO)2P4O13was solved and refined based on new single-crystal diffraction data revealing considerably more complexity than previously described. (NbO)2P4O13crystallizes in the triclinic space group P1̅ with Z = 6. The lattice parameters determined at room temperature are a = 1066.42(4) pm, b = 1083.09(4) pm, c = 1560.46(5) pm, α = 98.55(1)°, β = 95.57(1)°, γ = 102.92(1)°, and V = 1.7213(2) nm3. The superstructure contains 64 unique atoms including two disordered semioccupied oxygen positions. An unusual 180° bond angle between two [P4O13]6-groups was refined to form half-occupied, split positions in agreement with previous reports. The IR and Raman spectra reflect the appearance of overlapping bands assignable to specific group vibrations as well as P-O-P linkages present in the [P4O13]6-entities. Investigation of the powdered product concerning its photoluminescence properties revealed an excitability in the UV at 270 nm assigned to O2p-Nb4d charge transfer transitions. A resulting broad-band emission with the maximum in the visible region at 455 nm was determined.
authors.affiliation: Faculty of Chemistry and Pharmacy, Institute of General, Inorganic and Theoretical Chemistry, Leopold-Franzens-University Innsbruck , Innrain 80-82, 6020 Innsbruck, Austria.
authors.forename: Daniel
authors.initials: D
authors.lastname: Schildhammer
authors.affiliation: Faculty of Chemistry and Pharmacy, Institute of General, Inorganic and Theoretical Chemistry, Leopold-Franzens-University Innsbruck , Innrain 80-82, 6020 Innsbruck, Austria.
authors.forename: Gerda
authors.initials: G
authors.lastname: Fuhrmann
authors.affiliation: Faculty of Chemistry and Pharmacy, Institute of General, Inorganic and Theoretical Chemistry, Leopold-Franzens-University Innsbruck , Innrain 80-82, 6020 Innsbruck, Austria.
authors.forename: Lucas L
authors.initials: LL
authors.lastname: Petschnig
authors.affiliation: Faculty of Chemistry and Pharmacy, Institute of General, Inorganic and Theoretical Chemistry, Leopold-Franzens-University Innsbruck , Innrain 80-82, 6020 Innsbruck, Austria.
authors.forename: Klaus
authors.initials: K
authors.lastname: Wurst
authors.affiliation: Faculty of Chemistry and Pharmacy, Institute of General, Inorganic and Theoretical Chemistry, Leopold-Franzens-University Innsbruck , Innrain 80-82, 6020 Innsbruck, Austria.
authors.forename: Daniela
authors.initials: D
authors.lastname: Vitzthum
authors.affiliation: OSRAM GmbH, Corporate Innovation, Mittelstetter Weg 2, 86830 Schwabmuenchen, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Seibald
authors.affiliation: Faculty of Chemistry and Pharmacy, Institute of General, Inorganic and Theoretical Chemistry, Leopold-Franzens-University Innsbruck , Innrain 80-82, 6020 Innsbruck, Austria.
authors.forename: Herwig
authors.initials: H
authors.lastname: Schottenberger
authors.affiliation: Faculty of Chemistry and Pharmacy, Institute of General, Inorganic and Theoretical Chemistry, Leopold-Franzens-University Innsbruck , Innrain 80-82, 6020 Innsbruck, Austria.
authors.forename: Hubert
authors.identifier: http://orcid.org/0000-0002-2098-6087
authors.initials: H
authors.lastname: Huppertz