Formation of metallofullerenes with higher group elements

The formation of metallofullerenes was examined for 23 elements, and some e xperimental evidence was obtained for metallofullerenes with group-4, Zr an d Hf, and group-5, Nb, elements. Relative yields of the metallofullerenes e luted at the retention time around those for M@C-82 (M = group-2, and -3 el ements) were found to decrease exponentially as the group number increased. The yields for Fe and Co, namely group-8 and -9 elements, were estimated t o be less than one hundredth of that for M@C-82 (M = lanthanoid) (C) 1999 E lsevier Science B.V. All rights reserved.