The Kekule´ structure predicts that there
should be two different 1,2-dibromobenzenes. In practice, only one 1,2-
dibromobenzene has ever been found. Kekule´ proposed that these two forms
116 CH4 ORGANIC FUNCTIONAL GROUPS
are in equilibrium, which is established so rapidly that it prevents isolation
of the separate compounds. Later, this proposal was proved to be incorrect,
because no such equilibrium exists!