Diphenylene-Tetracyanoquinodimethane Cocrystals as Stable Organic Rectifiers

A promising cocrystal material that acts as a rectifier was prepared by a simple procedure of solution volatilization. (E)-1,2-diphenylethene (STB) and 7,7 ',8,8 '-tetracyanoquinodimethane (TCNQ) were used as donor and acceptor respectively, and aggregate in an ordered fashion in the stilbene-tetracyanoquinodimethane (STC) cocrystal that comprises 1 : 1 donor/acceptor mixed-stacked charge-transfer (CT) complexes. The strong CT interaction between the donor and acceptor is the main driving force for the self-assembly. The cocrystals show rectifying characteristics with a rectification ratio of 26. This result suggests that cocrystal engineering provides a great possibility to obtain rectifying materials from small, readily available organic molecules.