Phosphine physical constants

Ethyl dichlorophosphite is a colorless liquid, with an irritating odor. It fumes when exposed to air. It has the following physical constants sp. gr., 1.30526 b.p., 117.5° n °, 1.47176. It decomposes at 165° to ethyl chloride, phosphorus, phosphine, and phosphoric acid.3 It reacts with water to form hydrogen chloride and phosphorous acid, and with alcohols to form esters. When ammonia is passed through ethyl dichlorophosphite, ethyl phospheni-midate (ethoxyphosphimide), C2H5OP=NH, is formed. 

Quite recently, Kruck 118) obtained 80% yields of tetrakistrifiuoro-phosphine nickel by reaction at 100° C. and 350 atm. Clark and co-worker 56) studied the reaction mixture of Ni(CO)4 and PF3 by gas chromatography and NMR, determining the physical constants (density, vapor pressure) of all the substitution products, and showing that in first approximation the equilibrium composition of the mixture can be calculated if there was a statistical equilibrium between the ligands CO and PF3. This means that the metal-to-ligand bonds are of the same strength. 

The Dipole Moment of Phosphine.—Molecules which are not polar in the sense of being strong acids, bases or salts, may yet show an inner polarity when investigated by certain physical methods. The use of the dielectric constant and the refractivity in calculating the polarisation of molecules is described in certain monographs and text-books, e.g. The Dipole Moment and Chemical Structure, Debye-Deans (BlacMe), 1931 Recent Advances in Physical Chemistry, 1 Glasstone (Churchill), 1931. 

Tertiary phosphine analogs have been prepared from [Rh(NO)2Cl]x.1301 Nitrosyltris(phosphorus trifluoride)rhodium has been prepared from both rhodium(—I) and rhodium(I) complexes (equations 294-296).1297 Their physical properties are listed in Table 90. The triphenylphosphine complex is quite reactive (Scheme 42). Both electronic1312 and 31P NMR spectrometry show the equilibrium constant for the reaction (297) to be of the order of 10-4moldm3 in dichloromethane, benzene1312,1313 or THF,1313 so the reactivity of the complex cannot arise from the facile loss of a... 

The catalytic activities oftm are determined at constant phosphine to metal ratio, deliberately kept high on the polymer to minimize leaching of the metal from the support. (The problem of physical and chemical loss of metal complexes from polymer supports is review in the chapter by Garrou.) High phosphine to metal ratios reduce the fraction of coordinatively unsaturated sites reduce activity. In some cases higher activity of polymer-bound, more coordinatively unsaturated complexes may have been masked by diffiisional limitations, discuss in the chapter by Ekerdt. 

---