Synthesis and molecular properties of two isomeric dialkylated tetrathienonaphthalenes

Isomeric 2,8-distannyl 5,11-didodecyl αβ-TTN (1, tetrathienonaphthalene = TTN) and 2,8-didodecyl 5,11-distannyl αβ-TTN (2) have been designed and successfully synthesized. The naphthalene core structures in αβ-TTNs were constructed by a systematic protocol using PtCl ₂ -catalyzed cyclization followed by oxidative Scholl annulation in good yields. Compared to the one-dimensional naphthodithiophene derivatives, the two-dimensional αβ-TTN molecules showed good solubility, extended conjugation, strong absorptivity, and highly coplanar structures. Compounds 1 and 2 were polymerized with a 5,5′-dibromo-2,2′-bithiophene-based monomer to afford 2,8-αβ-PTTNTT and 5,11-αβ-PTTNTT copolymers. 2,8-αβ-PTTNTT with the α-aNDT moiety in the main chain exhibited a higher hole mobility of 1.26 × 10 ^-2 cm ² V ^-1 s ^-1 .