Fluorination, apparatus for

The typical fluorination apparatus used in the LaMar process for these reactions is simple in design (Fig. 4) (33). It is essential that the materials of constmction are resistant to fluorine (34). The presence of even traces of oxygen or moisture can have a deleterious effect and, therefore, extreme precautions must be taken to eliminate these contaminants. 

Long, G., Apparatus for Disposal of Fluorine on a Laboratory Scale, Harwell, AERE, 1956... 

Fluorodec [Fluorine on demand by electrolysis] An electrolytic process and apparatus for generating fluorine. The electrolyte is molten KHF2, the fluorine is liberated at a nickel anode. Offered by Fluorogas, UK. 

Dimethyl-2,3-dihydro-1,2-benzoisothiazolel,l-dioxide(60 g,0.304 mol)and NaF(16.8 g)in dry CHCI3 (500 mL) were cooled to — 40°C before the diluted mixture 10% F2/ N2 (w/ w) was introduced at a rate such that the flow in the second trap was about 15-25 mL min 1 (0.275 mol F2). After approximately 2 h, the contents of the second trap started to darken noticeably and the fluorination was discontinued. N2 was bubbled through the apparatus for about 1 h to purge the system of residual F2. The solvent was removed by rotary evaporation from the solution containing precipitate. After evaporation of the solvent, the crude mixture was purified by recrystallization from pentane (500 mL) at 0CC yield 42 g (64% from substrate, 71% from F2) mp 115-116.5 C. 

During World War II, plastics and lubricating compounds of unusual chemical and thermal stability were required for many applications, in particular for pumping apparatus used to separate 235U from 23SU by diffusion of corrosive uranium hexafluoride through porous barriers. It was natural to consider the use of substances made only of carbon and fluorine (fluorocarbons) for such purposes, and considerable effort was spent on methods of preparing compounds such as Today, many such substances are in common use. 

An Apparatus for the Fluorination of Halides of Non-metals. The discussion which follows is representative of the adaptation, by Prof. Harold S. Booth3 and his students, of the Swarts1 reaction to the fluorination of halides. 

Apparatus for preparations. All reactions were performed with a stainless steel vacuum line. Preparations were carried out in Teflon reactors assembled especially for each. The reactors were joined to the metal line via flexible fluorinated ethylene propylene (FEP) tubes and a polytetrafluoroethy-lene (PTFE) valve. FEP-tube reactors were prepared by first cutting lengths to —25 cm. These tubes were softened at one end by heating in a flame, then squeezed with broad-nose pliers to seal the end. One-armed reactors consisted of one of these tubes connected directly to a PTFE valve. T-shaped reactors had two of these tubes connected to a PTFE T-joint, which itself was connected via FEP tubing to a PTFE valve. All reactors were made vacuum-tight with PTFE swage connections. 

Figure 2.1 Fluorination apparatus used by Bigelow and Fukuhara for perfluorination of a variety of organic substrates (courtesy of the American Chemical Society) [6].

Fluorine, a yellowish-green gas, b.p. —188°, with an odor reminiscent of ozone and chlorine, is generally produced by electrolysis of KF-2HF this salt solidifies at ca. 100° and can thus be electrolysed in a steam-heated cell. Iron is used as the cathode, and graphite or nickel as the anode. Many types of apparatus for preparation of fluorine in the laboratory have been de-... 

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