Molten carbonate Introduction

Molten Carbonate Fuel Cells, Introduction - Cell Configuration, Features, and Cell Stack Size... 

The C—F bond energy is indeed very high (486 kJ mol-1 cf. C—H 415, and C—Cl 332 kJ mol"1), but organic fluorides are not necessarily particularly stable thermodynamically rather, the low reactivities of fluorine derivatives must be attributed to the impossibility of expansion of the octet of fluorine and the inability of, say, water to coordinate to fluorine or carbon as the first step in hydrolysis, whereas with chlorine this may be possible using outer d orbitals. Because of the small size of the F atom, H atoms can be replaced by F atoms with the least introduction of strain or distortion, as compared with replacement by other halogen atoms. The F atoms also effectively shield the carbon atoms from attack. Finally, since C bonded to F can be considered to be effectively oxidized (whereas in C—H it is reduced), there is no tendency for oxidation by oxygen. Fluorocarbons are attacked only by hot metals, e.g., molten sodium. When pyrolyzed, fluorocarbons tend to split at C—C rather than C—F bonds. 

The relationships between solubility, supersaturation, pressure, and temperature depend upon the details of the microscopic mechanisms operative in the context of the detailed active impurity chemistry and the specific geometric relationship set up between the source carbon, molten metal solution, and nucleation site, and or growing diamond. For an introduction into these extensive subjects the reader is referred to Burns and Davies [16] where the issues such as nitrogen and boron active impurity chemistries, diamond surface reconstruction, morphology and solvent/catalyst are discussed. 

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