Non-Kekulé molecule

Since non-Kekulé molecules have two or more formal charges or radical centers, their spin-spin interactions can cause electrical conductivity or ferromagnetism (molecule-based magnets), and applications to functional materials are expected.

The so-called Schlenk-Brauns hydrocarbons are:[2] Eugene Müller, with the aid of a Gouy balance, established for the first time that these compounds are paramagnetic with a triplet ground state.

After unsuccessful attempts by Erich Clar in 1953, trioxytriangulene was synthesized by Richard J. Bushby in 1995, and kinetically stabilized triangulene by Kazuhiro Nakasuji in 2001.

However, in 2017 a project led by David Fox and Anish Mistry from the University of Warwick in collaboration with IBM synthesized and imaged triangulene.

Other studied biradicals are those based on pleiadene,[15] extended viologens,[16][17] corannulenes,[18] nitronyl-nitroxide,[19] bis(phenalenyl)s [20] and teranthenes.

[21][22] Pleiadene has been synthesised from acenaphthylene and anthranilic acid / amyl nitrite: The oxyallyl diradical (OXA) is a trimethylenemethane molecule with one methylene group replaced by oxygen.