Investigation of single crystal structure on Tl2SO4 by neutron diffraction

• Published in: Physica. B, Condensed matter Condensed matter, 2018-12, Vol.551, p.6-8
• Main Authors: Oh, In-Hwan, Lee, Kwang-Sei
• Format: Article
• Language: English
• Subjects: A1. Lone-pair electrons; A2. Neutron diffraction; A3. Crystal structure; A4. Neutron scattering
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2017.11.058

The single-crystal neutron diffraction technique is employed to analyze the crystal structure of Tl2SO4. The crystal structure is composed of isolated SO4 tetrahedra and two symmetry independent Tl+ ions whose coordination numbers are 9 and 11. Although the concentration of lone-pair electrons is high, the stereochemical activity of the lone-pair electrons in the outermost 6s orbital of Tl+ ions is low. For Tl1, the variation in the TlO distances is relatively low compared to Tl2. They range from 2.880(6) Å to 3.385(6) Å for Tl1 and from 2.804(5) Å to 3.252(2) Å for Tl2, respectively. In the case of Tl1, except one TlO distance, all TlO bond lengths are bigger than 3 Å, but for Tl2, four TlO distances exceed 3 Å. It might indicate that the lone-pair electrons of Tl+ ions in this crystal structure prefer to occupy the space near Tl1.