Head-to-Tail Zig-Zag Packing of Dipolar Merocyanine Dyes Affords High-Performance Organic Thin-Film Transistors

Abstract

Attachment of bulky substituents at both thiophene donor (D) and thiazole acceptor (A) heterocycles of a dipolar (μ(g)=10.4 D) D-π-A merocyanine dye affords a more than 1 Å expansion of the common antiparallel supramolecular dimer motif in the solid state, enabling very close π-contacts (3.36 Å) to two other neighbor molecules on each of the two remaining π-faces. This unusual packing motif leads to three-dimensional percolation pathways for hole transport and affords thin-film transistors with mobility up to 0.64 cm(2) V(-1) s(-1).

Keywords: crystal structures; dipole moments; donor-acceptor dyes; merocyanine dyes; organic thin-film transistors.