1,1'-Biphenyl, 2,2',5,5'-tetrachloro-4,4'-bis(methylsulfonyl)- 2,2',5,5'-Tetrachloro-4,4'-bis(methylsulfonyl)-1,1'-biphenyl 4,4'-Bis(methylsulfonyl)-2,2',5,5'-tetrachlorobiphenyl 66640-68-4 Bmstbp