Formation of carbon black in the combustion of homogeneous hexane-air mixtures at pressure up to 1.5 MPa

An Unconventional Hydrofullerene C66H4 with Symmetric Heptagons Retrieved in Low-Pressure Combustion

“…By hydrogenation on the carbon cage, the HOMO−LUMO gap of dihept-C 66 is enlarged to 2.43 eV in dihept-C 66 H 4 , and the localizations of HOMO and LUMO are moved from adjacent pentagon regions to other carbons (Figure 5b and c), illustrating that the hydrogenation process in the combustion system is beneficial to the stability of the dihept-C 66 cage. With the four carbon atoms chemically modified at vertexes of the fused pentagon sites by hydrogen additions, hybridization states of hydrogenated carbon atoms are changed from sp 2 to sp 3 and the bond strains are remarkably released, finally affording the high stability of the dihept-C 66 H 4 structure.…”

“…The crystallographic data show that the dihept-C 66 H 4 contains C 2v -symmetric negative curvature moieties of heptagons accompanying fused pentagons. The four carbon atoms located at vertexes of the fused pentagon sites are chemically modified into sp 3 hybridization by hydrogen additions. Together with the heptagon involved, the sp 2 -to-sp 3 hybridization change of the vertex carbon atoms remarkably releases bond strains in the pristine dihept-C 66 , rendering the stability of the dihept-C 66 H 4 hydrofullerene.…”

“…The history of human beings using fire can be traced back to ancient times. When people began to use fire, they noticed that combustion produced carbon soot, which actually contains carbon-rich derivatives as well as carbon particles that have now been widely applied as raw materials (known as carbon black) in the rubber industry. − The composition of the carbon soot, however, is very complex and changeable with reaction conditions. Combustion at low-pressure with a proper C/O rate was reported for the synthesis of fullerenes in 1991 .…”