Caffeine

Caffeine's chemical name is 3,7-dihydro-1,3,7-trimethyl-1H-purine-2,6-dione. It is also known as theine, methyl theobromine, and 1,3,7-trimethylxanthine. Its molecular formula is C₈H₁₀N₄O₂• H₂O, and it consists of bicyclic molecules derived from the purine ring system.

In its pure form, caffeine is a fleecy white solid or long silky crystals. It is odorless, but has a distinctive bitter taste. When heated, caffeine loses water at 176°F (80°C), sublimes at 352.4°F (178°C), and/or melts at 458.2°F (236.8°C). It is only slightly soluble in water and alcohol, but dissolves readily in chloroform. Water solutions of caffeine are essentially neutral (pH = 6.9).

Caffeine is a member of the alkaloid family, a group of compounds obtained from plants whose molecules consist of nitrogen-containing rings. In general, alkaloids tend to have identifiable physiological effects on the human body, although these effects vary greatly from compound to compound.