Molecular orbital calculations are applied to the Raman scattering and ESR of pyrolytic carbons on the basis of small cluster models. The E2g and A1g modes of C-C stretching vibrations of coronene, hexabenzocoronene, and circumcoronene, which belong to D6h carbon clusters, are shown to appear around the 1550 cm-1 and 1360 cm-1 bands, respectively. The unpaired electrons observed in pyrolytic carbons are attributed to the bond-alternation defects on odd-numbered carbon clusters that are more easily mobile than those of trans-polyacetylene.
All Science Journal Classification (ASJC) codes
- Materials Science(all)