Electrocrystallization of Poorly Conducting Charge-Transfer Complexes

Electrocrystallization is a convenient technique for the synthesis of conducting and superconducting one-dimensional “organic metals” such as pyrene, tetrathiafulvalene, tetramethyl-tetraselenafulvalene, and recently bis(ethylenedithio)tetrathiafulvalene complexes. However, this method has not been exploited for poorly conducting charge-transfer complexes, which are generally prepared by cooling of saturated solutions or by metathetical methods. Precise control of the rate of crystallization, and subsequently the size and quality of crystals, is generally not attainable with these two methods. Described herein is the convenient electrochemical preparation of charge-transfer complexes in which one of the constituents is introduced at a controlled rate, thereby regulating the rate of crystallization.