Preparation, Crystal Structure, Vibrational Spectra, and Thermal Behavior of Tl2H2P2O6 and Tl4P2O6

Abstract

AbstractThe new thallium(I) salts, Tl2H2P2O6 (1) and Tl4P2O6 (2), were prepared and structurally characterized by single‐crystal X‐ray diffraction. Compound 1 crystallizes in the monoclinic space group P21/c and compound 2 in the orthorhombic space group Pbca. Both structures feature channels occupied by the lone electron pairs of Tl+ cations. Furthermore, those are built up by discrete [H2P2O6]2– for compound 1 and [P2O6]4– units for 2 in staggered conformation for the P2O6 skeleton and the thallium cations. In Tl2H2P2O6 (1) the hydrogen atoms of the [H2P2O6]2– ion are in a “trans‐trans” conformation. The O···H–O hydrogen bonds between the [H2P2O6]2– groups consolidate the structure 1 into a three‐dimensional network. FT‐IR/FIR and FT‐Raman spectra of the crystalline title compounds were recorded and a complete assignment for the P2O64– modes is proposed. The phase purity of 1 was verified by powder diffraction measurements.