Synthesis, spectroscopic and electrochemical properties of new covalent assemblies between TTF and various acceptors

• New electroactive tetrathiafulvalene based acceptor unit is synthesized.
• The whole E-configuration of the ethylenic bonds are confirmed by 1H NMR.
• The UV–visible electronic absorption spectra exhibit mainly two strong electronic absorption bands.
• All triads are characterized by an intramolecular charge transfer (ICT).
• The electron density of the HOMO orbital is located on the TTF fragment.

Five new acceptor-π–TTF-π-acceptor (A–D–A) triads that contain pyridine, quinoline, nitrophenyl or nitrofuryl groups as acceptor unit have been synthesized by two-fold Wittig olefination reactions and their electrochemical behavior has been studied by cyclic voltammetry (CV). The intramolecular charge transfer (ICT) band in these molecules was characterized by UV–visible electronic absorption spectroscopy and these studies were completed by DFT calculations in the gas phase. These materials appear to be good candidates for the preparation of electroactive discrete metal complexes or coordination polymers as well as for the preparation of radical cations salts.

Reagents and conditions: (i) LDA/THF, −78 °C, 1.5 h, (ii) DMF, 1 h at −78 °C, then 12 h et r.t and (iii) Et3N, acetonitrile, reflux 24 h.Figure optionsDownload as PowerPoint slide