It was found by C-13-NMR that the doping of iodine monobromide (IBr) i
nto C-60 solid changes significantly the electronic states of C-60, in
dicating chemical reaction between C-60 and halogen atoms, such as cha
rge transfer and bonding. On the other hand, no significant change in
C-13-NMR characteristics was observed in C-60 solids doped by iodine (
I-2) and iodine tricloride (ICI3). A possibility of metallic states at
C-60 sites was suggested by spin-lattice relaxation time measurement
in IBr-doped C-60.