Carbon dioxide, diamond synthesis

There are of course, in addition to the sp -carbon atoms on the surface, also the unsaturated ends of superficial graphitic structures that are saturated by the respective functional groups. Furthermore, a reaction with the cooHng medium can take place both on the diamond and on eventual graphitic structures. It is known, for instance, that lactones may be formed by the addition of carbon dioxide (coolant in the so-called dry synthesis. Section 5.3.1) to a reactive graphene layer. 

C. Chen, and T. Hong, The role of hydrogen in diamond synthesis from carbon dioxide-hydrocarbon gases by microwave plasma chemical vapor deposition, Sutf. Coat Technol, 54-55(l-3) 368-373 (1992)... 

Boron-Doped Diamond for Green Electro-Organic Synthesis, Scheme 6 Direct incorporation of carbon dioxide into an aminoacid precursor... 

Selection of the optimum medium needed to sustain detonation synthesis of ND is governed by the need to prevent oxidation of the detonation products that can occur in contact with atmospheric oxygen, as well as to provide the maximum possible rate of cooling of the ND formed to preclude transition of the diamond to graphite. In industrial-scale production of detonation ND, the explosive charges are placed in carbon dioxide, water, or solid carbon dioxide ( dry ice ). ... 

Depending on the used medium, the side products (detonation carbon) produced in detonation synthesis contain 20-70 wt% diamond. The remainder is a mixture of various structural forms of ip -carbon, the state of hybridized electronic orbitals characteristic of graphite. The yield of the diamond phase is the highest with carbon dioxide in the solid state, and the lowest, when it is in gaseous form. The medium most frequently used in industrial synthesis is water. 

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