91. Physical and chemical properties of organo-metallic compounds. Part I. The vapour pressures and freezing points of simple metal alkyls of Groups II, III, and V

Abstract

Bamford, Levi, avLd Newitt : Physical avLd 91.Measurements are recorded of the vapour pressures and freezing points of dimethyl-, diethyl-, di-n-propyl-, and di-n-butyl-zinc, trimethyl-, tri-n-propyl-, and triisopropyl-boron, solutions of trimethylboron in n-heptane, trimethyl-and triethyl-aluminium, trimethyl-and triethyl-stibine, dimethylcadmium and trimethylbismuth. From the vapour-pressure curves, the boiling points, latent heats of vaporization, and the Trouton constants have been calculated. I ;n recorded values of their physical constants. For example, in the case of the zinc alkyls recorded values of the boiling points differ by 2" for the dimethyl, by 5" for the diethyl and by 14" for the n-propyl derivative. No data for the freezing points of boron, aluminium, antimony, cadmium, and bismuth alkyls are available and the vapour-pressure data are scanty or absent.In the course of an investigation into the properties of a series of these compounds, described in subsequent papers, advantage has been taken of the availability of pure specimens to determine the vapour pressuretemperature curves, freezing points and, in some instances, the heats of combustion. The vapour-pressure and freezing-point data are included in the present paper. EXPERIMENTAL.Pressures are measured by a Bourdon gauge B, which is maintained at any desired temperature by the air-jacket J , and can be read to 0.01 mm.We wish to thank Miss B. M. Gaunt, B.Sc., for valuable assistance in preparing the pure samples of alkyls used in this work.Pressures were measured over the range 0-120" without any evidence of decomposition.This was prepared from n-butyl iodide by the above method.Similarly, diethylmercury (20 g.) and aluminium (6 g.) gave an almost theoretical yield. This was prepared by the action of antimony trichloride on the Grignard reagent.Yield, 45%. Triethylstibine.The ether was separated by repeated fractionation under reduced pressure and in a vacuum. Yield 80%.

Production of Nanometer-Sized Metal Oxide Particles by Gas Phase Reaction in a Free Jet. I: Experimental System and Results

“…The TMA bubbler was operated at room temperature (21°C), corresponding to a calculated vapor pressure of 10.0 mm Hg (Bamford et al, 1946). Raman spectrum measurements indicate oxide formation times of 0.037 ms for a TMA-0, flame under stoichiometric conditions at 4.1 mm Hg and an adiabatic flame temperature of 2600 K (Vanpee and Seamans, 1967).…”

Vapor pressures of dimethylcadmium, trimethylbismuth, and tris(dimethylamino)antimony

“…As the mass fraction of mercury impurities in our sample did not exceed 0.5 ppm and the contamination of our sample by mercury during the vapor pressure measurements using the STAT7 apparatus can be ruled out, this hypothesis is not supported by our data which show good agreement with those reported by Li [25] for all measured and derived thermodynamic properties. Other literature vapor pressure data for (CH 3 ) 2 Cd [27,28] seem to be less accurate. The data reported by Bamford et al [28] deviate up to 28% and those reported by Anderson and Taylor [27,28] up to 17%.…”

“…Other literature vapor pressure data for (CH 3 ) 2 Cd [27,28] seem to be less accurate. The data reported by Bamford et al [28] deviate up to 28% and those reported by Anderson and Taylor [27,28] up to 17%.…”

“…For (CH 3 ) 3 Bi, two literature sources reporting the vapor pressure measurements were found [28,29]. While the data reported by Amberger [29] …”

“…(the deviations do not exceed 4.5% in the overlapping temperature range), the data by Bamford et al [28] deviate significantly (up to 52%). We note that the producers of metalorganic precursors use in their catalogs almost exclusively the vapor pressure equations taken from Bamford et al [28] despite already shown significant discrepancies of these values [1].…”