2,5-Cyclohexadien-1-one, 4,4'-(3-(2,3,4,5-tetrachloro-2,4-cyclopentadien-1-ylidene)-1,2-cyclopropanediylidene)bis(2,6-bis(1,1-dimethylethyl)- 4,4'-(3-(2,3,4,5-Tetrachloro-2,4-cyclopentadien-1-ylidene)-1,2-cyclopropanediylidene)bis(2,6-bis(1,1-dimethylethyl)-2,5-cyclohexadien-1-one) 63165-92-4