1,1,4,4-tetracyanobutadienes (TCBDs) have interesting optoelectronic properties, such as an exceptional electron-accepting ability and intense non-linear absorption.

Yann Trolez, Université de Rennes 1, France, and colleagues, have investigated the reactivity of ynamides with tetracyanoethylene (TCNE) in dichloromethane. The team has found that these reactions yield novel TCBDs in good to excellent yields (example pictured). The reaction could be applied to systems bearing two conjugated ynamide moieties. Reactions with arylynamines have also been investigated, and lead to TCBDs in good yields.

Electrochemical measurements showed that the TCBD compounds have exceptional electron-accepting properties. UV/Vis spectroscopy indicated that these TCBDs exhibit a tunable absorption from the UV to the visible range, depending on the substrate. According to the researchers, these optoelectronic properties could be useful for electronic devices in the future.

• Reactivity of functionalized ynamides with tetracyanoethylene: scope, limitations and optoelectronic properties of the adducts,
  Marie Betou, Raphaël J. Durand, Antoine Sallustrau, Claire Gousset, Erwann Le Coz, Yann R. Leroux, Loïc Toupet, Elzbieta Trzop, Thierry Roisnel, Yann Trolez,
  Chem. Asian J. 2017.
  DOI: 10.1002/asia.201700353