Reference

Synthesis of vinyl fluoride by the hydrofluorination of acetylene and by the dehydrofluorination of 1,1-difluoroethane in the presence of fluorine-containing catalysts

Synthesis of vinyl fluoride by the hydrofluorination of acetylene and by the dehydrofluorination of 1,1-difluoroethane in the presence of fluorine-containing catalysts. Usmanov, Kh. U.; Sirlibaev, T. S.; Akramkhodzhaev, A.; Saparniyazov, K.; Yul'chibaev, A. A. (Task. Gos. Univ., Tashkent, USSR). Zh. Prikl. Khim. (Leningrad), 51(8), 1839-42 (Russian) 1978. CODEN: ZPKHAB. ISSN: 0044-4618. DOCUMENT TYPE: Journal CA Section: 35 (Synthetic High Polymers) Section cross-reference(s): 23 Vinyl fluoride (I) [75-02-5] and 1,1-difluoroethane (II) [75-37-6] were obtained by hydrofluorination of acetylene (III) [74-86-2] in the presence of g-Al2O3-SbF3 catalyst, and I was obtained by dihydrofluorination of II in the presence of g-Al2O3-SbF3 or g-Al2O3-Cd(BF4)2 catalysts. Most efficient were catalysts contg. 10% SbF3 or 4% Cd(BF4)2. For example, full conversion of III to a mixt. contg. 22-6% I and 70-6% II was obtained at 305-15° in the presence of the former catalyst. The latter catalyst gave I in ￡85% yield in dehydrofluorination of II.

Chemistry of nuclear recoil fluorine-18 atoms

Chemistry of nuclear recoil fluorine-18 atoms. 10. Studies of fluorine-18 caged capture processes in 1,1,1-trifluoroethane/hydrogen sulfide and 1,1-difluoroethane/hydrogen sulfide liquid mixtures. Manning, Ronald G.; Root, John W. (Dep. Chem., Univ. California, Davis, Calif., USA). J. Phys. Chem., 81(25), 2576-86 (English) 1977. CODEN: JPCHAX. DOCUMENT TYPE: Journal CA Section: 70 (Nuclear Phenomena) Abs. nuclear recoil 18F [13981-56-1] yields were detd. for liq.-phase fluoroethane-H2S mixts. at H2S [7783-06-4] concns. ranging to 50 mol. %. The results were interpreted by using contrasting Miller-Dodson (M.D.) and steady-state nonthermal kinetic formulations. The M.D. collision densities do not change significantly with the addn. of H2S. Nonthermal rate coeffs. are closely comparable and independent of mixt. compn. for F-to-HF reactions with H2S, MeCF3 [75-37-6], and MeCHF2 [75-37-6], exceeding by roughly 5-fold the composite values that include all fluoroethane org. reaction channels. Branching ratios for 18F energetic bimol. vs. caging reactions are independent of H2S concn. In contrast with the predictions of collision-theory cage-effect models, efficient F-to-HF reactions do not interfere with primary caged capture. Excitation functions for energetic F-to-HF processes in H2S and fluoroethanes are crudely similar and extend to center-of-mass energies of 25 eV or more.