C2v-Symmetric C60 Isomer in the Gas Phase: Experimental Evidence against Buckminsterfullerene (Ih-C60)

Pure non-IPR (isolated-pentagon-rule) C 60 isomer has rarely been investigated experimentally. The recently reported availability of #1809 C 60 Cl 8 opens an avenue for experimental investigation of #1809 C 60 , a C 2v -symmetric C 60 isomer having two pairs of fused pentagons. Herein, the experiments on #1809 C 60 were performed on the basis of thermal dechlorination of #1809 C 60 Cl 8 in the solid state and gas phase. #1812 C 60 Cl 6 was employed for comparative study. As determined by Raman and other methods, #1809 C 60 from thermal decomposition of #1809 C 60 Cl 8 crystals readily coalesces to form carbon solid with a collapsed crystal lattice. In contrast, dechlorination via thermal spray of #1809 C 60 Cl 8 in the gas phase is feasible for investigation of monodispersed all-carbon C 60 isomer, because the existence of #1809 C 60 in the gas phase has been confirmed by experimental evidence from mass spectrometry and high-performance-liquid-chromatography.