Electronic spectra and geometries of HgX3– in water

Abstract

The electronic spectra, in the visible and u.v. regions, of HgX₃^–(X = Cl, Br, or I) have for the first time been obtained, by a computer technique, free from any contributions of HgX₂ or HgX₄^2–, and the resolved bands are assigned and permit identification of HgCl₃^– as planar with D_3h symmetry, and HgI₃^– as pyramidal, with C_3v symmetry, which suggests that the solvated species are trigonal-bipyramidal and tetrahedral, respectively; HgBr₃^– has possibly intermediate or pyramidal geometry.