The Crystal Structure of Sodium Perxenate Octahydrate

Abstract

The presumed minor importance of the 6s orbitals in the bonding would also be worthy of quantitative investigation. Such refinements would, of course, substantially increase the size of the problem, and they would be expected to result in only relatively small changes in the energies so that the essence of the present conclusions regarding the structure would remain unaltered.The Bi95+ species is evidently the first example of a homopolyatomic cation of a metallic element that is sufficiently stable to exist in a pure state, excepting, of course, the diatomic Hg22 + and Cd22+. It is interesting to note that this grouping may not be without analogy, however, since it is isoelectronic with Pbg4~and Sn94-, two (of many) species of the post-transition metals for which Zintl and co-workers16 found evidence in liquid ammonia. This relationship has also been noted by Britton.20 On the other hand, no evidence for a bis-(19) Summarized by H. J. Emeléus and J. S. Anderson in "Modern Aspects of Inorganic Chemistry," 3rd Ed., D. Van Nostrand Co., New York, N. Y., 1960, p. 512.muth analog of Pbv4~, the other lead anion suggested by Zintl's work, has been found in the BiCb-Bi system.In addition there is no evidence for any comparable, polynuclear cation of antimony in the SbXg-Sb system,21•22 perhaps due to its reluctance to form cations in the presence of halide. Compositions corresponding to the many species suggested by Zintl are generally not found in the binary alloy systems although a few isolated examples of other homopolyatomic ions with "closed-shell" MO's may occur in the latter.23 Continued investigations may well disclose other examples of such ions for the post-transition elements that are commonly thought of as metallic in character.Acknowledgments.-J. D. C. is particularly indebted to J. W. Richardson for the overlap computations and to D. S. Martin, Jr., for helpful discussions.

Ultraviolet Photolysis Studies on XeO4 in Noble‐Gas and F2 Matrices and the Formation and Characterization of a New XeVIII Oxide, (η2‐O2)XeO3

“…The differences between calculated frequencies and experimental values for the 18 O‐enriched compounds remain essentially constant over the series of Xe 16/18 O 4 isotopomers. Overall, the absolute values of the 16/18 O isotopic shifts of XeO 4 are greater than those of [XeO 6 ] 4− (Table 3), in accordance with the relative bond strengths and XeO bond lengths of XeO 4 (1.736(2) Å)5 and [XeO 6 ] 4− in NaXeO 6 ⋅ 8 H 2 O (1.864(12) Å) 18…”

Neutron diffraction study of the space group and structure of manganeseleonite, K2Mn(SO4)2.4H2O

“…The bisector of the lone pair orbitals of H2Ow(2) is directed toward the manganese ion Mn(1); but Ow(2) has, in addition, two potassium neighbours at 3.09 A nearly normal to the plane of the molecule leading to an approximately trigonal bipyramidal coordination for H2Ow(2). Somewhat similar coordinations, though with different types of neighbours, have been observed recently in sodium perxenate octahydrate (Ibers, Hamilton & Mackenzie, 1964). The coordination types of H2Ow(1) and H2Ow(2) are relatively rare and no examples of these were known to us at the time of our classification referred to above.…”

IV - Isoelectronic systems

“…is correct." 8 Infinite Anion Lattices Sodium peroxide is written Na202, not NaO, because it is known from X-ray data (and, less directly, from chemical data) that the oxygen atoms in the crystal occur, understandably enough, in pairs; for 0" ions arc isoelectronic with fluorine atoms, which are known to dimerize. This simple observation may be generalized.…”