Fluorocarbon derivatives

T. J. Brice, R. 1. Coon, and W. A. Severson, "Properties of Some Fluorocarbon Derivatives of Sulfur Hexafluoride," paper presented at American Chemical Society, Minneapolis, Minn., 1955. 

Electrolysis of organic sulfides in FIF affords a variety of fluorocarbon derivatives ... 

Electronic Effects in Metallocenes and Certain Related Systems, 10, 79 Electronic Structure of Alkali Metal Adducts of Aromatic Hydrocarbons, 2, 115 Fast Exchange Reactions of Group I, II, and III Organometallic Compounds, 8,167 Fluorocarbon Derivatives of Metals, 1, 143 Heterocyclic Organoboranes, 2, 257... 

Recently, Germain et al. have also shown that the indirect anodic oxidation in fluorosulfuric add of fluorocarbon derivatives of the type RfCF2X (X — H, COOH, S03H, CH2OH, Br), which are not directly oxidizable, leads to fluorosulfates of the type FSG3CF3Rf (Eqs. 18 and 19) [37, 38], in these reactions, the peroxide (FS03)2, partially dissociated in its free radicals, is the in-situ electrochemically produced reactive intermediate as shown in Scheme 5.1. 

Miller (90), King (209, 210), and Bruce (211) first observed the formation of neutral metal fluoride species and metal fluoride-containing ions in the mass spectra of pentafluorophenyl derivatives of phosphorus, germanium, silicon, and phosphido-bridged iron carbonyls (90) and aliphatic and aromatic fluorocarbon derivatives of iron, cobalt (209-211),... 

In 1938, while attempting to prepare fluorocarbon derivatives, Roy J. Plunkett, at DuPont s Jackson Laboratory, discovered that he had prepared a new polymeric material. The discovery was somewhat serendipitous as the TFE that had been produced and stored in cylinders had polymerized into poly(tetra-fluoroethylene) (PTFE), as shown in Eigure 4.2. It did not take long to discover that PTFE possessed properties that were unusual and unlike those of similar hydrocarbon polymers. These properties include (1) low surface tension, (2) high Tm, (3) chemical inertness, and (4) low coefficient of friction. All of these properties have been exploited in the fabrication of engineering materials, wliich explains the huge commercial success of PTFE. 

Fluorocarbon derivatives have another interesting and potentially useful property. They dissolve large quantities of oxygen. This fact, combined with their nontoxicity, has led to their use as blood replacements in heart surgery on experimental animals. Mice can live totally immersed in oxygen-saturated liquid fluorocarbons. 

Henry Gilman and Gerald L. Schwebke Fluorocarbon Derivatives of Metals... 

I. Mass Spectra of Fluorocarbon Derivatives of Transition Metals. 113... 

The first mass spectral studies on fluorocarbon derivatives of metal carbonyls were reported in 1961 68> the octafluorotetramethylene derivative C4FsFe(CO)4 (34) and the octafluoro-l,3-cydohexadiene... 

The nomenclarnre of fluorocarbon derivatives is based on regarding them as derivatives of the corresponding hydrocarbon compounds. 

Part of the interest in fluorocarbon systems lies in a comparison of the chemistry, and particularly reaction mechanisms, of fluorocarbon derivatives with those of the corresponding hydrocarbon compounds. Indeed, such comparisons pose quite a strenuous test on our theories of organic chemistry. As will be seen, our understanding of the influence of carbon-fluorine bonds on reaction mechanisms has made considerable progress. Nevertheless, it must be emphasised that fluorocarbon derivatives present much more complicated systems than their corresponding hydrocarbon compounds because, in addition to effects arising from different electronegativities, the effect of the lone pairs of electrons of fluorine that are not involved in o-bonds must be taken into consideration. Furthermore, the relative importance of these effects seems to be very dependent on the centre to which the fluorine is attached. 

R. N. Haszeldine, Fluorocarbon Derivatives, Royal Institute of Chemistry, London, 1956. 

The fact that exchange occurs to produce, in each case, the fluorocarbon derivative is quite consistent with the general observation that exchange generally proceeds to give a product where the metal is bonded preferentially to the most electronegative group [33]. 

The increased susceptibility to hydrolysis of the fluorocarbon derivatives over their hydrocarbon analogues is illustrated by pentafluorophenylboronic acid which is stable in acid solution, whilst pentafluorophenyl is rapidly lost in neutral or basic solution [78] (Figure 10.31). 

However, two pentafluorophenylaluminium derivatives, 10.35A and 10.35B, have been isolated [85] by cleavage of the mercurial (Figure 10.35). Both 10.35A and 10.35B eventually explode violently on heating and this occurs with 10.35A at about 195° C. Nevertheless, the relative stability of these uncomplexed fluorocarbon derivatives may be attributed to bromine bridging, which saturates the covalency of aluminium and inhibits migration of fluorine from carbon to aluminium. Evidence from NMR spectra indicates either stmcture shown in Figure 10.36 for compound 10.35A. 

Fluorocarbon derivatives of copper have been studied quite widely, probably because there is little evidence for the elimination of metal fluoride being a limitation in these systems. Early work [118] showed that when perfluoroiodoalkanes are heated with copper in DMSO or DMF, then the copper compounds are formed in solution and these have been successfully applied in a variety of coupling reactions. High-dielectric media are essential to the success of these processes (Figure 10.57). 

P. M. Treichel and Advan. Organometal. Fluorocarbon derivatives of metals 78 ... 

T. Wada Kagaku (Kyoto) 18, Fluorocarbon derivatives of metals 6 ... 

Another possible explanation for enhanced stabilities of perfluoro-alkyltransition metal compounds concerns possible multiple bonding between the metal and the fluorocarbon group 230). Whatever the reason, a large number of fluorocarbon derivatives of the transition metals have now been described, and a study of their synthesis, properties, and reactions constitutes an important new branch of organotransition metal chemistry. Fluoroalkyltransition metal compounds were first described in 1959 J 8), while perfluoroary 1-transition metal derivatives were discovered in 1963 201, 234). Some typical syntheses of fluorocarbon-transition, metal compounds are shown below ... 

Fluorocarbon derivative rubbers Isobutylene-isoprene rubbers Isocyanate type rubber Isoprene rubbers, synthetic N-type rubber Neoprene Nitrile type rubber Nitrile-butadiene rubbers Polybutadienes... 

Examples of cyclization in this section are dominated by classical methods of synthesis that have been modified to produce appropriate fluorocarbon derivatives. Other authors5,156 have discussed this area in more detail than is contained here we have largely given representative examples rather than comprehensive coverage. 

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