Electron Donor‐Acceptor Compounds, 46 Molecular Structures and Charge‐Transfer Absorptions of [2.2]‐, [3.3]‐, and [4.4] Paracyclophanes with Tetracyanobenzene as Acceptor Unit

Abstract Based on X‐ray analyses the molecular structures of the electron donor‐acceptor [2.2]‐ and [3.3]paracyclophanes 1, 2, 4, 6, 10 , and 11 are discussed in terms of steric and electronic effects. The charge‐transfer absorptions of 1–9 were measured and are dealt with in correlation to the variation of the strength of the electron donors and of the donor‐acceptor distances in the series 1–9 .