A new method for the preparation of molybdenum and tungsten oxotetrafluorides

Conclusions A new method has been proposed for the synthesis of molybdenum and tungsten oxotetrafluorides by the reaction of the metal trioxide with the corresponding hexafluoride in a glass reactor.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2643–2644, November, 1985.     

Insertion of Ethyl Isocyanate at the Tungsten–Chlorine Bond. Crystal Structure of 1,3,5-Triethyl-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione

The reaction of tungsten hexachloride with excess ethyl isocyanate in dichloroethane leads to the insertion of three ligand molecules at one of the tungsten–chlorine bonds. The data of elemental analysis and IR spectroscopy confirm that the thermolysis of the reaction mixture affords the WCl₄(L₃Cl) complex (I), where L = –N(Et)C(O)–. The structure of the chain of inserted molecules in I is established on the basis of IR and NMR data, and the results of X-ray diffraction analysis of crystals of an organic product (II) of the hydrolysis of I. According to the latter, compound (II) is a derivative of s-triazine—1,3,5-triethyl-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione.     

Geometric structure and vibration frequencies of Re2F8

A complex electron diffraction and mass spectrometric investigation of the saturated vapor of rhenium tetrafluoride has been carried out. The principal molecular form in the vapor phase at T=471 K is the dimer Re₂F₈. The geometric structure of the Re₂F₈ molecule has the equilibrium eclipsed conformation of symmetry D_4h with a triple bond, ReRe. The barrier to internal rotation of the ReF₄ groups relative to one another is 2.8±2.8 kJ/mole. The vibration frequencies of the Re₂F₈ molecule have been estimated on the basis of the experimental amplitudes of vibration.Ivanovo Chemical Technology Institute. Translated from Zhurnal Strukturnoi Khimii, Vol. 34, No. 2, pp. 46–54, March–April, 1993.