1,1'-Biphenyl, 2,2',5,5'-tetrachloro-4-(methylsulfonyl)- 2,2',5,5'-Tetrachloro-4-(methylsulfonyl)-1,1'-biphenyl 4-Meso2-tcb 4-Methylsulfonyl-2,2',5,5'-tetrachlorobiphenyl 60640-55-3