The formation of the mixed anions PAsO7 in solid solutions Mg2P2O7 — Mg2As2O7

Abstract

The article presents structural features at formation of solid solutions of the isostructural Mg₂P₂O₇ and Mg₂As₂O₇ connections. In these compounds, complex Р₂О₇^4-anions, As₂O₂^4-, as well as the formation of complex PAsO₇⁴ anions, is not natural. The formation of solid solutions is confirmed by the linear dependence of x-ray debaegram and optical refractive indices, depending on the concentration of P/As. In the article, phosphates are involved in energy processes in cells. For the first time, the formation of mixed anions in polyphosphates has been proven. The oscillatory spectra of pyro anions have intervals of localization of terminal and bridging groups of atoms that have no intersection regions. Strip at 662–670 cm^-1 (between structures from P: As=0.8:0.2 to 0.1–0.9), located between v_sPOP frequency in ᵦ — Mg2P2O7 at 737 cm-1 and the frequencies about 550 cm^-1 characteristic of fluctuations of v_sAsOAs in alkaline pyroarsenates, is interpreted as a strip of fluctuations of v_sPOAs of the mixed PAsO₇ ions. In the area, the strip at 925–902 cm^-1 is located between frequencies of fluctuations of v_asPOP and v_asAsOAs. The fluctuations of mastic group P-O found in ranges of infrared absorption allow establishing knowledge of the adjacent anions (PAsO₇)^4- that it is possible to confirm with quantum-chemical calculations in the subsequent.