Annulated Azuleno[2,1,8?<i>ija</i>]azulenes: Synthesis and Properties

Non-alternant non-benzenoid hydrocarbons exhibit very different optical and electronic properties than their well-studied benzenoid analogues. However, preparing such structures with extended conjugation length, remains challenging. Herein, we report the synthesis of azuleno[2,1,8-ija]azulene derivatives using a two-step sequence involving four-fold aldol condensation between aromatic dialdehydes readily available tetrahydropentalene-2,5-(1H,3H)-dione. Molecules band gap values ranging from 1.69 to 2.14 eV molar extinction coefficients (?) nearly 3×105 M?1 cm?1 have been prepared. These annulene-like significant diatropic ring currents (aromatic), as supported by 1H NMR spectroscopy DFT calculations. Field-effect transistors (OFETs) semiconductors charge mobility up 0.05 cm2 V?1 s?1.