Tetra(4‐hexylphenyl) [3]‐ and [5]Cumulenes

ABSTRACT The synthesis of [3]‐ and [5]cumulenes bearing 4‐hexylphenyl endgroups, [3]PhHex and [5]PhHex , has been developed. The incorporation of alkyl groups is designed to enhance film formation by improving solubility. Although tetraaryl[3]cumulenes are typically quite stable, the head‐to‐tail dimerization of [3]PhHex is observed after prolonged storage under ambient conditions, and the dimer is characterized crystallographically. The crystallographic analysis of [5]PhHex in comparison with other tetraaryl[5]cumulenes demonstrates changes in packing as a function of increasing size of the alkyl group. Preliminary characterization of field‐effect transistors fabricated with [3]PhHex , in comparison with the parent compound tetraphenyl[3]cumulene [3]Ph , shows poorer performance for [3]PhHex and emphasizes the need to optimize film‐forming protocols for new cumulenic semiconductors.