Preparation and NMR characterization of C₇₀H₁₀: Cutting a fullerene π-system in half

Three isomers of C₇₀H₁₀ were prepared by Zn(Cu) reduction of C₇₀. Three chromatographic bands were identified as C₇₀H₁₀ species by MALDI-FT mass spectrometry, and these compounds were isolated by repeated HPLC treatments. The major isomer (2) was characterized by ¹H and ¹³C NMR, while the minor isomers 3-4 were isolated in such small quantities that only ¹H NMR analysis was possible. ¹H-coupled and ¹H-decoupled ¹³C NMR of 2 established a 7,8,19,26,33,37,-45,49,53,63-substitution pattern. This assignment was confirmed by HMBC and DFQ-COSY experiments. This structure is completely reasonable, as we found that 2 results exclusively from reduction of the 7,19,23,27,33,37,44,53-C₇₀H₈ that is formed in the course of the Zn(Cu) reduction of C₇₀.