Tetraaminoethylenes as Strong Electron Donors

Depending on the nature of the electron acceptor and of the tetraaminoethylene (TAE), the electron pairs of the ethylenic double bond (A), of the nitrogen (B), or of the entire electronic system (C) of TAE react with the acceptor. Thus oxidizing agents convert TAE into the mono‐and dications TAE + and TAE 2+ by path (A); acids add on to the ethylenic carbon (A) or the amine nitrogen (B) (the addition of acid is often followed by cleavage of the CC or CN bond); organic π‐electron acceptors from deeply colored donor‐acceptor complexes with TAE (C).