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15. 6. 2004.
Algebraic Kekule Structures of Benzenoid Hydrocarbons.
An algebraic Kekule structure of a benzenoid hydrocarbon is obtained from an ordinary Kekule structure by inscribing into each hexagon the number of π-electrons which (according to this Kekule structure) belong to this hexagon. We show that in the case of catafusenes, there is a one-to-one correspondence between ordinary and algebraic Kekule structures. On the other hand, in the case of perifusenes, one algebraic Kekule structure may correspond to several ordinary Kekule structures.