Asymmetric annellation effects—IV : Dibenzacenes☆

摘要: Abstract The asymmetric annellation effects and the shift difference rule are explained on basis of two schemes A B. asymmetry in passing from acenes to 1:2-benz-, 1:2,3:4-dibenzacenes support scheme B involving view that transition a cyclic conjugated polyene into benzenoid ring produces violet spectral shift. Another set annellations is found heteronuclear dibenzacenes. This series can be started ethylene. merits symplified valence bond theory considered for interpretation effects. assumption transferable electrons capable migrating through rings an acene leads π-electron levels benzene with 4 π-electrons mobile double bonds lower level 2 moving freely about not belonging any bond.