Synthesis and reactions of [Et3NH]4[Mo8O6]: X-ray crystal structure of [Et3NH]3[NaMo8O26]

McCann, M., Maddock, K., Cardin, C. ORCID: https://orcid.org/0000-0002-2556-9995, Convery, M. and Quillet, V. (1994) Synthesis and reactions of [Et3NH]4[Mo8O6]: X-ray crystal structure of [Et3NH]3[NaMo8O26]. Polyhedron, 13 (5). pp. 835-840. ISSN 0277-5387 doi: 10.1016/S0277-5387(00)81691-5

Abstract/Summary

[Et3NH]4[Mo8O26] (1) was prepared by reacting triethylamine with either molybdenum trioxide dihydrate or with a solution of ammonium molybdate in aqueous HCl. An aqueous solution of complex 1 reacted with an excess of sodium chloride to give a mixture of [Et3NH]3[NaMo8O26] (2) and [Et3NH]2[Mo6O19] (3). Complex 2 was also formed on reacting sodium molybdate with triethylamine in aqueous HCl. In the reaction of 1 with potassium chloride the nature of the product obtained was critically dependent upon reaction time. After a 5.5 h reflux period a mixture of [Et3NH]3[KMo8O26] (4) and 3 was obtained, whereas upon prolonged reflux (24 h) only K4Mo8O26 · H2O (5) was precipitated. The X-ray crystal structure of 2 shows it to be polymeric, with each Na+ ion sandwiched between two β[Mo8O26]4− ions. Four oxygen atoms on one face of each β[Mo8O26]4− ion are coordinated to a Na+ ion, and four oxygens from the opposite face are bonded to the next Na+ ion in the polymer chain. This produces a zig-zag arrangement of Na+ ions throughout the molecular structure. Spectral, conductivity and voltammetry data are given.