Dorota Sendor

One dimensional energy transfer in lanthanoid picolinates. Correlation of structure and spectroscopy

Optical and structural properties of rare earth complexes with 2-pyridine carboxylic acid (‘Hpic’) are evaluated by luminescence spectroscopy, decay measurements, X-ray crystal structure determination, FTIR, DTA and metal content analysis. Corresponding Tb3+and Eu3+ complexes of this ligand are extraordinarily efficient with respect to their luminescence. In the crystalline state the series is isostructural and composed of M[Ln(pic)4]·nH2O (M = Na, NH4; Ln = Eu, Gd, Tb, Ho) with pic-linked [Ln(pic)4]− units forming a chain-like structure, which gives rise to a one-dimensional exchange communication between the rare earth ions; this energy transfer being confined to the chains. Energy transfer of the Coulomb type between the ligands appears to be of significance only, if suitable rare earth acceptor states are not accessible, as is shown for a series of [La(pic)4]− series, in which La3+ is gradually substituted by Tb3+ or Eu3+.

Transformation of nanoporous oxoselenoantimonates into Sb2O3—nanoribbons and nanorods

We have isolated flexible Sb2O3 nanoribbons and nanorods as the main product from the disintegration of nanoporous oxoselenoantimonates of the cetineite type, the size of the one-dimensional nanomaterials obtained ranging up to 15 microm in length with diameters between 8 and 50 nm.

In-sity X-ray detection of Xe adsorption in cetineites

Cetineites are chalcogenoantimonates and may act like molecular sieves such as zeolite, but in contrast they are semicoductors and they exhibit an optical band gap in the visible range. In-situ X-ray experiments during adsorption/desorption in different atmospheres were performed and indicate that the long hexagonal tubes built up from [SbO 3 ] pyramids with a diameter of about 7are suitable to take up Xe atoms. This may allow the application of as a gas sensing material for the detection of noble gases.