Trifluorovinyl methyl, ethyl, isopropyl and tert-butyl ethers have been prepared. These trifluorovinyl ethers show C=C absorption at such a short wavelength as 5.46∼5.50μ. The methyl and ethyl ethers can be polymerized by free-radical initiators. Halogen addition products of trifluorovinyl- and 1, 2-difluoro-2-chlorovinyl ethers have also been prepared. With α-halo or vinyl ethers, the reactions that are catalyzed by acids, including decomposition, are best interpreted as proceeding through the carbonium ion stabilized by carbonium-oxonium resonance.

Measurements of densities and refractive indices at 632?8 nm were carried out for glassy slags from the systems CaF 2 -CaO-SiO 2 and NaF-Na 2 O-SiO 2 at room temperature to derive the electronic polarisability of F (a F ). First, a F was derived assuming that the fluorides did not depolymerise the silicate network. Values of a F for xCaF 2 -(100-x)(CaO.SiO 2 ) and x(2NaF)-(100x)(3Na 2 O.7SiO 2 ) increased with increasing concentrations of CaF 2 and NaF and approached those of a F for single crystal CaF 2 and NaF, respectively. Values of a F for 5CaF 2 -xCaO-ySiO 2 also increased with increasing basicity of (mol-%CaO)/(mol-%SiO 2 ). Smaller values of a F suggest that F ions are in more covalent bonding than CaF 2 and NaF, leading to the possibility of forming Si-F bonds in the slags. Second, the number ratio of F forming Si-F bonds (N F(in Si-F) ) to the total F (N Total F ) was calculated assuming that part of the fluoride depolymerised the silicate network. The N F(in Si-F) /N Total F ratios decreased with decreasing number of bridging oxygen ions.

The molecular structure of 1,2-difluorotetrachloroethane was studied by the electron diffraction method. The existence of the two isomeric forms, trans and gauche, was ascertained and the amount of the gauche form was found to be 55±10 per cent. This corresponds to the energy difference of 0−500 cal./mol. the trans form being more stable. The interatomic distances and the valency angles were determind as follows: C—F=1.38±0.02 Å, C—Cl=1.76±0.01 Å, C—C=1.54±0.06 Å, <CCCl=112°±2°, <ClCCl=110°30′±1°, <FCCl=107°30′±1°30′, and the azimuthal angle of the gauche form=59°±4°. The C—F bond distance in this molecule is greater than those distances of compounds having more than one fluorine atom bonded with a carbon atom. On the other hand, the C—Cl bond distance seems to be slightly shorter than those of chloro-alkanes having no substituted fluorine atom.

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