Tetrafluoride Subject

Unless silicates are removed here, they are likely to be confused with Al(OH)3 in the group separation. Repeated evaporation with concentrated HC1 converts silicates into a granular form of hydrated silica, which is readily filtered, particularly after a final digestion with dilute HC1. The precipitate should be subjected to the microcosmic salt bead test or to the silicon tetrafluoride test (Section IV.26). 

The failure of difluoramine to appear among the final products is not particularly surprising. In the presence of nitric acid and/or nitrogen oxides, it might easily be oxidized and may well constitute the source of the silicon tetrafluoride. The formation of a carbonium ion from trityl-difluoramine would be favored by resonance stabilization. In the tert-butyl case, on the other hand, this driving force is not present and formation of the ion would be expected to occur less readily. In addition, both the tert-butyl carbonium ion and the difluorammonium ion from which it is derived would be more subject to a variety of side reactions than the corresponding trityl species. 

In complete contrast to the above results is the oxidation of the estrone (20) by hydrogen peroxide in hydrogen fluoride/antimony tetrafluoride. When subjected to hydroxylating conditions using this reagent, the estrone (20) gave a poor-yielding mixture of the oxidized products (21-23 Scheme 8). 

Sulfur tetrafluoride is very stable when compared to the lower sulfur fluorides. It can be stored at room temperature for an indeflnite period of time. It is very reactive and is valued as a selective fluorinating agent for both organic and inorganic compounds. Its remarkable fluorinating ability has been the subject of recent reviews. ... 

Two further methods of preparing organoboron compounds have been the subject of fairly recent detailed study, namely, reaction of boron halides with hydrocarbons and addition of boron hydrides to olefins. For instance, arylboron dihalides are formed when boron trihalides are heated with aromatic hydrocarbons, aluminum chloride, and aluminum powder,217 and phenyl-boron dibromide has been prepared analogously.218 Further, boron halides such as diboron tetrachloride and tetrafluoride add to olefins, yielding bis-(dichloroboryl) and bis(difluoroboryl) compounds 219... 

As the name implies, the species that do the etching in this technique are gaseous plasmas generated within an evacuated chamber to which is introduced the etchant precursor gas(es) and which is subjected to high-frequency electric power via external electrodes. These plasmas comprise ionic and neutral fragments. For a precursor etchant gas such as carbon tetrafluoride (CF4), species including C, CF" ", CF, C, F, CF, CF2, and CF3 have been detected in the generated plasma. ... 

He received a Master Degree in Chemistry in 1956 and a PhD in Science in 1962 at the Central University of Madrid. The subject of his thesis was Quantum Mechanical Study of the Electronic Stmcture of Carbon Tetrafluoride . In 1963 he won a postdoctoral scholarship at the Centre de Mecanique Ondulatoire Appliquee of CNRS in Paris (France), where he worked with Roland Lefebvre and also met Jean Mamani, who was starting his thesis in this group. During the same period he was a lecturer in Theoretical Chemistry at the Sorbonne. 

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