Molecular formula: C₁₂H₁₀
Structural formula:

Properties: White or slightly yellow squamous crystal
Purity (chromatograph): ≥95% (first grade), ≥90% (second grade)
Use: Used as raw material of engineering plastic polysulfone, heat carrier and preservative, and to produce trichlorodiphenyl, pentachlorodiphenyl and dye.