1,1'-Biphenyl, 2,2',5,5'-tetrachloro-4,4'-diiodo- 2,2',5,5'-Tetrachloro-4,4'-diiodo-1,1'-biphenyl 2,2',5,5'-Tetrachloro-4,4'-diiodobiphenyl 36649-77-1 4,4'-Diiodo-2,2',5,5'-tetrachlorobiphenyl