SYNTHESIS OF A DERIVATIVE OF TRIANGULENE - THE FIRST NON-KEKULE POLYNUCLEAR AROMATIC

The first synthesis of a non-Kekule polynuclear aromatic, a trioxy der ivative of triangulene, has been achieved through a two-electron reduc tion of tetrabutylammonium 4,8-dioxo-4H,8H-dibenzo[cd,mn]pyren-12-olat e 14. The single crystal X-ray diffraction structure of this precursor shows it to be essentially planar with a three-fold axis of symmetry. The trioxytriangulene produced when it is reduced also possesses a th ree-fold axis of symmetry and it has a tripler ground state. The powde r ESR spectrum obtained is that for a uniaxial system fitted using the parameters \D/hc\ = 0.0064 cm(-1), \E/hc\ = 0.0000 cm(-1). It is stab le at room temperature but very sensitive to air oxidation.