Two-Dimensional Brickblock Arrangement in Bis-Fused Tetrathiafulvalene Semiconductors

Molecular packing arrangement is a very important factor in the charge carrier mobility of organic semiconductors, but its rational design has not been established as yet. Two-dimensional (2D) lamellar packing is an advantageous arrangement for high charge mobility, but few examples have been reported thus far. Herein we show crystal structures and the electronic properties of newly designed bis-fused tetrathiafulvalene (TTF) semiconductors with hetero substituent groups with distinct electronic effects. Unprecedented 2D lamellar alignment is achieved in a single crystal, where the bis-fused TTF rings interact three dimensionally with face-to-face and side-by-side intermolecular S center dot center dot center dot S contacts up to a total of 20 sites per pi molecule and form graphitelike "brickblock" structure. The charge mobility of a single crystal is as high as 0.78 cm(2) V-1 s(-1). Systematic investigations of the semiconductors reveal a key role of intramolecular S center dot center dot center dot O interaction between a bis-fused TTF ring and a methoxycarbonyl group in controlling efficient arrangement, leading to high mobility.