Porphyrin-Cyclophanes with 7,7,8,8-Tetracyanoquinodimethane as an Especially Strong Electron-Acceptor: Syntheses, Properties, Electron-Transfer Interactions

Previous work on intramolecular electron-transfer compounds of the quinone-porphyrin cyclophane type with gradually increasing electron-acceptor strength was now extended to acceptor-porphyrin cyclophanes with 7,7,8,8-tetracyanoquinodimethane (TCNQ) as an especially strong electron-acceptor. The vertically stacked TCNQ-porphyrin cyclophane 1 was prepared in a multi-step synthesis. Physical properties related to structure and electron-transfer processes of 1 are reported. To determine the distance dependence of the interaction between the electron-acceptor TCNQ and the porphyrin, first results on the synthesis of the corresponding naphthalene-spacered TCNQ-porphyrin cyclophane 15 are presented.