Two crystalline modifications of RuO4

摘要

RuO4 was prepared by oxidation of elemental ruthenium. Two different modifications were obtained and investigated by X-ray single crystal diffraction. RuO4-I has cubic symmetry (P4;(-)3n, Z = 8, a = 8.509(1) angstrom), and two independent tetrahedral molecules are present in the unit cell. Within the standard uncertainties in both molecules the distances Ru-O are 1.695 angstrom. The second modification, RuO4-II, is monoclinic (C2/c, Z = 4, a = 9.302(4) angstrom, b = 4.3967(10) angstrom, c = 8.454(4) angstrom, beta = 116.82(3)degrees) and isotypic with OsO4. There is one independent molecule in the unit cell, which shows distances Ru-O of 1.697 and 1.701 A, respectively. (c) 2005 Elsevier Inc. All rights reserved.