The compounds α-TlBiP2Se6 (I), β-TlBiP2Se6 (II), TIBiP2S6 (III), Tl3Bi3(PS4)4 (IV), TlBiP 2S7 (V), and Tl3Bi(PS4)2 (VI) were synthesized, and the structures of I-V were determined by single-crystal X-ray diffraction analysis. The structure of I features infinite chains. Those of compounds II, III, and V are layered. The structure of IV features a three-dimensional framework. Tl4Bi2(PS 4)2(P2S6) (VII) was also prepared for comparison to the title compounds. The band gaps of each compound are 1.23, 1.27, 1.81, 1.88, 2.06, 1.98, and 1.97 eV for I-VII, respectively. Compounds I, III, IV, and VI melt congruently at 544, 595, 495, and 563°C, respectively, and compounds II, V, and VII melt incongruently at 544, 509, and 600°C, respectively. Solid-state 31P NMR spectroscopy of the reported compounds demonstrates chemical shifts and chemical shift anisotropies in line with related chalcophosphate materials. Evidence for two-bond P-TI J coupling was observed in 31P NMR spectra (J = 481-1781 Hz), and to the best of our knowledge, this is the first example of two-bond P-TI J coupling and the first example of P-TI coupling in the solid state. It was possible to assign chemical shifts of inequivalent 31P atoms from the same [P xQy]z- anion type based on different modes of metal ion coordination to the chalcogen. These assignments provide information about the vicinal metal ion contribution to the 31P chemical shift.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry