Electrocrystallization where the reactants are confined in two dimensions yields a whole class of unexpected monoclinic polymorphs of the triclinic, prototypical tetramethyltetraselenafulvalene and tetramethyltetrathiafulvalene salts (see Figure). The crystal and electronic structures, as well as the conductivity, of these new and previously known polymorphs of Bechgaard and Fabre salts are described.