Preparation, Structural Characterization and Electrical Properties of Some Polyatomic Cations of Mercury

Abstract

<p>The preparation of a number of new compounds containing mercury in formally low oxidation states is reported. The preparations are described and Raman spectra are reported for Hg₂(AsF₆)₂.SO₂, Hg₂(AsF₆)₂, Hg₂(Sb₂F₁₁)₂.SO₂, Hg₂(SbF₆)₂.SO₂, Hg₂(SbF₆)₂, and Hg₂(SO₃F)₂. All of the mercurous salts have been prepared for the first time. The preparations of Hg₃(AsF₆)₂ and Hg₃(Sb₂F₁₁)₂, both of which contain the Hg₃²⁺ cation are presented. The Hg₄²⁺ cation, which has not been identified previously, is present in Hg₄(AsF₆)₂. The preparation of this compound and its Raman and UV-visible spectra are discussed. Raman spectroscopic and x-ray crystallographic studies show that the ions are linear, and that the bond lengths increase in the order Hg₂²⁺ < Hg₃²⁺ < Hg₄²⁺.</p> <p>Two new compounds containing infinite, linear, non-intersecting chains of mercury atoms in two mutually perpendicular directions have been prepared. The bonding in the metal atoms chains can be described as metallic, with the charge delocalized over the mercury atom chains.</p> <p>An experimental technique for measuring the electrical conductivity of these extremely hygroscopic compounds is described, and conductivity and optical studies show that the compounds are anisotropic, metallic conductors. They constitute a new class of anisotropic materials.</p>