Bicyclic Dienes and Beyond

There are many bicyclic dienes and polyenes. If for no other reason than to show that seemingly homologous series often show profound complications, in Table 3 we present the enthalpies of formation of the bicyclo[2.2.n]alka-2,5-dienes, bicyclo[2.2.n]alk-2-enes and bicyclo[2.2.n]alkanes, species 68, 69 and 70, respectively, wherein we limit our attention to the cases of n = 0, 1 and 2. It is seen that the enthalpies of formation of the bicycloalkadiene, bicycloalkene and bicycloalkane always become more negative in that 

TABLE 3. Recommended enthalpies of formation of bicyclo[2.2.n]alka-2,5-dienes, bicyclo[2.2.n]alk-2-enes and bicyclol 2.2.n al kanes for n = 0, 1 and 2 

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