Synthesis, Crystal Structure, and Optical Properties of the Barium <i>meta</i>-Pertechnetate Ba[TcO<sub>4</sub>]<sub>2</sub>
High-quality single crystals of the colorless title compound Ba[<sup>99</sup>TcO<sub>4</sub>]<sub>2</sub> were prepared from radioactive, isotope-pure <sup>99</sup>TcO<sub>2</sub> by oxidation with H<sub>2</sub>O<sub>2</sub> in an aqueous ammonia solution and subsequent cation metathesis using an ion-exchange column. Single-crystal X-ray diffraction revealed Ba[TcO<sub>4</sub>]<sub>2</sub> to crystallize isotopically to Ba[MnO<sub>4</sub>]<sub>2</sub> in the orthorhombic space group <i>Fddd</i> with the lattice parameters <i>a</i> = 747.34(5) pm, <i>b</i> = 1244.08(7) pm, and <i>c</i> = 1511.23(9) pm for <i>Z</i> = 8. Its crystal structure features [BaO<sub>12</sub>]<sup>22-</sup> icosahedra surrounded by ten [TcO<sub>4</sub>]<sup>-</sup> tetrahedra connected via two edges and eight corners. The optical properties of Ba[TcO<sub>4</sub>]<sub>2</sub> investigated by UV-vis spectroscopy show the broad O<sup>2-</sup> → Tc<sup>7+</sup> ligand-to-metal charge transfer (2p → 4d) process within these discrete [TcO<sub>4</sub>]<sup>-</sup> anions at an absorption maximum of around 350 nm.
Authors
- Maurice Conrad (ORCID: https://orcid.org/0000-0002-8898-773X)
- Thomas Schleid (ORCID: https://orcid.org/0000-0001-5808-0128)
- Thomas E. Albrecht‐Schmitt (ORCID: https://orcid.org/0000-0002-2989-3311)
Institutions
- University of Stuttgart (DE)
- Colorado School of Mines (US)
Publication Details
- Journal
- ACS Omega
- Published
- 2025-04-04
- DOI
- https://doi.org/10.1021/acsomega.5c00481
- Citations
- 2
- Primary Topic
- Crystal Structures and Properties
- Type
- article
- Field-Weighted Citation Impact
- 0.85
Funders
- Basic Energy Sciences