Recently, it was reported that crystals of the organic material dithiophene-tetrathiafulvalene (DT-TTF) have a high field-effect charge carrier mobility of 1.4 cm(2)/(V x s). These crystals were formed by a simple drop-casting method, making this material interesting to investigate for possible applications in low-cost electronics. Here, organic single-crystal field-effect transistors based on materials related to DT-TTF are presented and a clear correlation between the crystal structure and the electrical characteristics is observed. The observed relationship between the mobilities in the different crystal structures is strongly corroborated by calculations of both the molecular reorganization energies and the maximum intermolecular transfer integrals. The most suitable materials described here exhibit mobilities that are among the highest reported for organic field-effect transistors and that are the highest reported for solution-processed materials.

The variation of the number and position of OH substituents a t the phenyl ring of a-phenyl nitronyl nitroxide radicals yields different hydrogen-bonded molecular self-assem blies with distinct dimensionalities; the mono-ortho-su bstituted isomer is most remarkable since it shows a three-dimensional network of weak hydrogen bonds exhibiting a bulk ferromagnetic transition at 0.45 K.

Pairs of stacks of organic donors D in the salt [(DT‐TTF)2][Au(mnt)2] (DT‐TTF = dithiophene‐tetrathiafulvalene, mnt = maleonitriledithiolate) form a classical ladder structure due to three close S …︁ S interactions (see picture). Below 225 K the double stack of donor molecules forms a spin ladder with two legs, which arises through localization of unpaired electrons in the (DT‐TTF)2 dimers.