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 PtCl2-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 cm2 V–1 s–1.