Fluorescent materials anthraquinones

When sublimed, anthraquinone forms a pale yeUow, crystalline material, needle-like in shape. Unlike anthracene, it exhibits no fluorescence. It melts at 286°C and boils at 379°—381°C. At much higher temperatures, decomposition occurs. Anthraquinone has only a slight solubiUty in alcohol or benzene and is best recrystallized from glacial acetic acid or high boiling solvents such as nitrobenzene or dichlorobenzene. It is very soluble in concentrated sulfuric acid. In methanol, uv absorptions of anthraquinone are at 250 nm (e = 4.98), 270 nm (4.5), and 325 nm (4.02) (4). In the it spectmm, the double aUyflc ketone absorbs at 5.95 p.m (1681 cm ), and the aromatic double bond absorbs at 6.25 p.m (1600 cm ) and 6.30 pm (1587 cm ). 

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