ELECTROCHEMICAL STUDY OF SOME BROMO-SUBSTITUTED [2.2]PARACYCLOPHANES

The potentials of electrochemical oxidation (E(1/2)(Ox)) and reduction (E(1/2)(Red)) of monobromo- and isomeric di- and tribromo[2.2]paracyc lophanes as well as E(1/2)(Ox) of mono-, di-, and tribromobenzenes wer e measured in acetonitrile. The similarity between the properties of p seudo-para-disubstituted cyclophanes and meta-disubstituted benzenes, on the one hand, and pseudo-meta-disubstituted cyclophanes and para-di substituted benzenes, on the other hand, was confirmed by the existenc e of a linear relationship between E(1/2)(Red) of bromo-substituted [2 .2]paracyclophanes and E(1/2)(Red) of the corresponding bromo-substitu ted benzenes. The results were explained in terms of the qualitative t heory of molecular orbitals, taking into account a ''through space'' i nteraction between the pi-systems of the benzene rings.