1 2 3 4 5-tetrachlorobenzene July 8, 2019 16 32 64 128 2 4 5 6-tetrachlorobenzene-1 3-dicarbonitrile 1 2 4-trichlorobenzene 1 2 3-trichlorobenzene 1 2 5 trichlorobenzene 1 2 3 4-tetrachlorobenzene 1 2 4-trichlorobenzene cas number