Studies on new aspects of Quinone Chemistry

<p>Quinones are organic compounds that are formally derived from aromatic</p><p>compounds such as benzene or naphthalene. During the conversion an even</p><p>number of (CH) groups are oxidised into (C=O) groups and necessary double</p><p>bonds are rearranged to get fully conjugated cyclic dione structure1. Apart from</p><p>this organic molecules such as phenols and catechols having electron donating</p><p>substituents are easily oxidized to quinones. The electron donating substituents</p><p>increase the nucleophilicity of the ring and contributes to the large redox</p><p>potential needed to break the aromaticity (quinones are conjugated but not</p><p>aromatic).</p><p>Many natural and artificial colouring substances (dyes and pigments) are quinone</p><p>derivatives. They are next to azo dyes in importance as dyestuffs with particular</p><p>emphasis on blue colours. Alizarin {12-dihydroxy-910-anthraquinone} (8)</p><p>extracted from the madder plant was the first natural dye to be synthesized from</p><p>anthracene. This was used as the prominent red dye for dyeing textile fabrics.</p>