Benzene, C(6)H(6), is a clear, colorless, flammable liquid that is insoluble in water.Its boiling point is 80 degrees C (176 degrees F). In the past benzene was obtained from the distillation of coal in the absence of air. Today most benzene is made syntheticallyfrom petroleum products. The benzene is a closed ring of six atoms connected by bonds that resonatebetween single and double bonds; each carbon is also bound to a single atom. Benzene isinsoluble in water but mixes in all proportions with organic . Benzene is itself an excellentsolvent for certain and for most simple organic chemicals. It is one of the most commonly used solvents in the organic chemical laboratory.
If inhaled in large quantities, benzene is poisonous. The vapors are explosive andthe liquid violently flammable. Many compounds are obtained from benzene. It is alsoused in the manufacture of and in the production of important derivatives. Benzene andits derivatives are included in the important chemical group known as . When mixed with alarge proportion of , benzene makes a satisfactory . In Europe, benzene mixed with other compounds has long been added to motor fuels.
Benzene was isolated in 1825 by Michael Faraday, but its structure remained amystery for 40 years. The problem was perplexing because the C(6)H(6) formula indicateda high degree of unsaturation, but benzene does not display the reactivity characteristic of such compounds.
In 1865, German chemist Friedrich August Kekule von Stradonitz proposed thatbenzene is structurally a planar hexagon in which the six carbon atoms are joined byalternating single and double bonds. Because this simplistic structure could not accountfor all of the unique properties of benzene and its derivatives, German chemist JohannesThiele suggested in 1899 that the bonds between carbon atoms exhibit resonance. That is,each bond oscillates between being a double and a single bond (see aromatic compounds). In modern...