Redox properties of linear and cyclic scaffolds based on Di- and tetraethynylethene

A large selection of linear and cyclic acetylenic scaffolds based on functionalized di- and tetraethynylethenes (DEEs, TEEs) have been prepared during the past ten years, such as poly(triacetylene)s (PTAs), expanded dendralenes, or perethynylated expanded radialenes and dehydroannulenes. These carbon-rich oligoenynes are interesting for their electronic and advanced materials properties. In this account, we highlight their redox properties. Moreover, the electrochemistry of cyanoethynylethenes (CEEs), a class of powerful electron acceptors that have recently attracted our attention, since they combine the scaffolding potential of TEEs with the superior acceptor strength of tetracyanoethene (TCNE), will also be discussed. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).