Modulation of the Electronic Properties of 3π-2spiro Compounds Derived from Bridged Oligophenylenes: A Structure–Property Relationship

3π-2spiro compounds are constituted of three π-systems linked through two shared spiro carbons leading to a three-dimensional architecture. The modulation of the electronic properties of such molecular systems can be achieved through the modification and/or substitution of their different π-systems and by the modification of their geometry. The present work is focused on the tuning of the electrochemical properties of a wide range of 3π-2spiro compounds based on fluorenyl, xanthenyl, 2,7-disubstituted fluorenyl, 1,2-b- or 2,1-a-indenofluorenyl, and pentaphenylenyl fragments with a main emphasis on the localization of the successive electron transfers. A detailed structure-property relationship study of interest for the organic electronics scientific community is then drawn.