A Building Block for Organic Electronic Material Incorporating A Reactive 1,2-Diketone Moiety Forming Tetracene Derivatives

Acenes incorporating a linear-shaped structure with plural fused-benzene rings are useful materials for organic electronics. Accordingly, a building block for the acene derivative can be an important raw material to develop a new electronic material. In 2011, Matsuo et al. reported cyclopenta[fg]tetracene-1,2-dione (1) that is a tetracene derivative with a 1,2-diketone moiety. This has a more extended acene structure compared with those of acenaphthylene-1,2-dione and aceanthrylene-1,2-dione.¹⁾ 1 is particularly stable to oxidation compared with a normal tetracene, because there is an additional group on the unstable moiety of tetracene.

The single crystal X-ray analysis of 1 showed a highly planar structure of the molecule in the crystal, and there are π-stacking conformations between the planar molecules.¹⁾ Matsuo et al. reported that 1 reacted with 1,2-phenylenediamines to form several π-extended pyrazine derivatives.²⁾ Further introduction of a disulfide group to the pyrazine derivatives gave a low band gap material showing photoabsorption up to ca. 800 nm. Characteristics of organic field-effect transistors (OFET) fabricated by the pyrazine derivatives were also reported,²⁾ thus we can further expect synthetic development of a new tetracene-based material derived from 1 as a building block.

Packing structure of 1 viewed along the c axis