Formation, Isolation, Spectroscopic Properties, and Calculated Properties of Some Isomers of C60H36

Isomers of C60H36 and He@C60H36 have been synthesized by the Birch or dihydroanthracene reduction of C60 and isolated by preparative high-pressure liquid chromatography. 3He, 13C, and 1H NMR spectroscopic properties were then determined. A comparison of experimental chemical shifts against those computed using density functional theory (B3LYP) with polarized triple- and double-ζ basis sets for He and C,H, respectively, allowed provisional assignment of structure for several isomers to be made. Theoretical calculations have also been carried out to identify low-energy structures. The transfer hydrogenation method using dihydroanthracene gives a major C60H36 isomer and a minor C60H36 isomer with C3 symmetry as determined by the 13C NMR spectrum of C60H36 and the 3He NMR spectrum of the corresponding sample of 3He@C60H36. In view of the HPLC retention times and the 3He chemical shifts observed for the Birch and dihydroanthracene reduction products, the two isomers generated by the latter procedure can be onl...