Bulk Production of a Strong Covalently Linked (C60Hx)2 Dimer

The high-pressure treatment of C 6 0 in an H 2 atmosphere at high temperatures leads to the efficient formation of a covalently bound dimer and some oligomeric species. The resulting hydrogenated C 1 2 0 is an example of the bulk production of covalently bound derivatized fullerene cores. Matrix-assisted laser desorption/ionization in conjunction with reflectron time-of-flight mass spectrometry has been applied to the product analysis. The dissociation pattern of selected C 1 2 0 H 2 x + ions (x > 30) indicates the dimeric structure of (C 6 0 H x ) 2 , as opposed to a giant hydrofullerene species possessing a fused C 1 2 0 core. However, the results also clearly indicate a much stronger bonding (multiple a bonding) between the C 6 0 H x units than present in cycloaddition products. Evidence of a covalently linked dimer was obtained in labeling experiments, on the basis of which any laser-induced gas-phase aggregation of the C 6 0 H x monomer during the analysis is discounted.